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Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Dist. - Nadia, West Bengal PIN - 741 252

The university established in 1974, has completed five decades of its existence as the pioneer institute of Agricultural Education, Research and Extension. The main objective of this Viswavidyalaya is to provide facilities for the study of Agriculture, Horticulture and Agricultural Engineering. It is also to conduct researches in these sciences and undertake the educational and extension programmes in agriculture among the rural clientele base, keeping in view the requirements of the state.

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    ThesisItemOpen Access
    IMPACT OF CROP ESTABLISHMENT METHOD, NUTRIENT MANAGEMENT AND STUBBLE HEIGHT OF HYBRID RICE ON RICE – LENTIL CROPPING SEQUENCE
    (Agronomy, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia – 741252, 2023-12-22) Sana Megha; Dr. Sukanta Pal
    A 2-year study on “Impact of crop establishment methods, nutrient management and stubble height of hybrid rice on rice-lentil cropping sequence” was undertaken at RRSS, BCKV, Chakdaha in kharif and rabi seasons of 2020-21 and 2021- 22. The experimental soil was sandy clay loam in texture with neutral pH (7.1, 7.2), medium OC (0.680 and 0.681%), low available N (261.5 and 263.7 kg ha-1) and medium available P2O5 (16.30 and 17.20 kg ha-1) and medium available K2O (130.0 and 134.0 kg ha-1). The field layout plan was done as per strip-strip plot design with 24 treatment combinations and three replications. The treatments represent 3 factors: the main plot factors namely two different crop establishment methods [transplanted rice (TPR) and direct seeded rice (DSR)], the sub-plot factors namely six nutrient doses [Farmers fertilizer practice (60 kg N, 30 kg P2O5 and 30 kg K2O per hectare), 100% RDF (80 kg N, 40 kg P2O5 and 40 K2O per hectare), 150% RDF (120 kg N, 60 kg P2O5 and 60 K2O per hectare), 75% RDN + 25% N via Municipal compost + Azospirillum @ 2 kg ha-1, 50% RDN + 50% N via Municipal compost + Azospirillum @ 2 kg/ha, SSNM based on Nutrient Expert® (i.e. 91-42-48 kg N, P2O5, K2O ha-1)], two different stubble length (15 cm and 25 cm) was in sub sub-plots. There were 72 total plots with a 12 m2 each plot size. The results of the present experiment indicate that different crop establishment methods have profound impact on growth and yield of hybrid rice. During both kharif seasons, growth attributes of hybrid rice, for all the dates of observation were found to be higher in transplanted crop than that of, direct seeded crop. Transplanted crops recorded highest plant height (114.21cm and 114.30cm at 90 DAT), number of tillers m-2 (431.40 and 446.64 at 90 DAT), LAI (4.45 and 4.54 at 60 DAT), above ground biomass (1089.1g m-2 and 1096.5g m-2 at harvest), CGR (17.95 g m-2 day-1 and 17.64 g m-2 day-1 during 31- 60 DAT), third leaf nitrogen concentration (2.43% and 2.47% at 60 DAT), root length (24.62cm and 24.67cm at 90cm DAT) and root dry weight (261.5 g m-2 and 269.8 g m-2 at 90 DAT) in both kharif seasons, respectively. Among the nutrient levels, during both years for all dates of observation, treatment receiving 150% RDF performed best with respect to growth attributes of hybrid rice, closely followed by Nutrient Expert® treatment; And both the treatments (F6) were statistically at par among themselves. Application of 150% RDN recorded highest plant height (119.32cm and 123.22cm at 90 DAT), number of tillers m-2 (469.1 and 492.3 at 90 DAT), LAI (4.78 and 5.16 at 60 DAT), above-ground biomass (1044.8g m-2 and 11058.3g m-2 at harvest), third leaf N concentration (2.72% and 2.77% at 60 DAT), root length (24.74cm and 24.82cm at 90 DAT) and root dry weight (270.4 g m-2 and 281.7 g m-2 at 90 DAT) in both the years, respectively. Application of 50% RDN + 50% N through municipal compost + Azospirillum (F5 treatment) produced plants with highest CGR (18.53 g m-2 day-1 and 18.72 g m-2 day-1 in kharif 2020 and 2021 respectively). With respect to different CEM and nutrient management treatments, yield attributes of hybrid rice followed a similar trend as that of growth attributes for both the years. Transplanted crops produced higher number of panicle m-2 (250 and 253), number of filled grains per panicle (105 and 109), panicle length (28.74cm and 27.42cm), panicle weight (3.51 g and 3.65 g), 1000-grain weight (22.24 g and 22.23 g), grain (6.34 t ha-1 and 6.36t ha-1), straw (6.25 t ha-1 and 6.40 t ha-1) yield and HI (50.34% and 49.95%) in kharif 2020 and kharif 2021, respectively than that of direct seeded crops. Treatment consisted of 150% RDN performed best with regard to effective number of panicle m-2 (259 and 263), number of filled grains per panicle (120 and 123), panicle length (28.98 cm and 28.32 cm), panicle weight (3.64 g and 3.91g), test weight (22.29 g and 22.53 g), grain (7.16 t ha-1 and 7.15t ha-1), straw (7.33 t ha-1 and 7.46 t ha-1) yield and HI (49.25% and 49.29%) in kharif 2020 and kharif 2021, respectively. Hybrid rice in FFP treated plots had lowest values for all measured parameters. The content and N uptake (1.206%, 1.229% and 77.35 kg ha-1, 78.81 kg ha-1), P content and P uptake (0.302%, 0.311% and 19.57 kg ha-1, 20.19 kg ha-1) and K content and K uptake (0.360%, 0.366% and 23.06 kg ha-1, 23.57 kg ha-1) of rice grains was found to be highest in transplanted crops during kharif 2020 and kharif 2021, respectively. Irrespective of CEM, application of 150% RDN (F3 treatment) showed highest N content and N uptake (1.225%, 1.268% and 88.18 kg ha-1, 91.35 kg ha-1), P content and P uptake (0.339%, 0.347% and 24.48 kg ha-1, 25.08 kg ha-1) and K content and K uptake (0.384%, 0.402% and 27.68 kg ha-1, 28.73 kg ha-1) of rice grains in kharif 2020 and kharif 2021, respectively. Significantly higher crude protein content in hybrid rice grain (7.538% and 7.683%), hulling percentage (76.23% and 77.15%) and milling percentage (71.04% and 71.15%) were obtained in transplanted crop during kharif 2020 and kharif 2021, respectively. Irrespective of CEM, application of 150% RDN (F3 treatment) produced grains with highest crude protein content (7.658% and 7.924%), hulling % (76.37% and 77.59%) and milling % (70.25% and 70.34%) in kharif 2020 and 2021, respectively. At the end of both the kharif seasons, the under different CEMs soil organic carbon content (SOC) in 0-15 cm soil depth remained unaltered. The available N (378.74 kg ha-1 and 278.54 kg ha-1), P2O5 (26.34 kg ha-1 and 37.01 kg ha-1) and K2O (176.26 kg ha-1 and 175.65 kg ha-1) in soil was found to be the highest in direct seeded rice plots in kharif 2020 and kharif 2021, respectively. Irrespective of CEMs, application of 50% RDN + 50% N through municipal compost + Azospirillum (F5 treatment) led to higher content of organic carbon (0.65% and 0.67%), N (388.44 kg ha-1 and 394.12 kg ha-1), P2O5 (31.27 kg ha-1 and 33.67 kg ha-1) and K2O (185.23 kg ha-1 and 199.18 kg ha-1) in soil after harvesting of hybrid rice in 2020 and 2021, respectively; while the lowest values were recorded in plots which received FFP. In this 2-years field experiment, the highest cost of cultivation was incurred in transplanted hybrid rice cultivation with F5 treatment (₹99332 ha-1). The gross (₹183020 ha-1 and ₹181805 ha-1) and net (₹96247 ha-1 and ₹93737 ha-1) return as well as B:C ratio (2.11 and 2.08) were found to be the highest in transplanted hybrid rice cultivation with F3 treatment in kharif 2020 and kharif 2021, respective. The lentil crop, sown after harvesting of DSR, recorded highest plant height (38.71cm and 39.77cm at 90 DAS), dry aerial biomass (131.95g m-2 and 136.20g m-2 at 90 DAS), CGR (2.026g m-2 day-1 and 1.933 g m-2 day-1 during 31-60 DAS), number of nodules plant-1 (32.09 and 34.57 AT 60 DAS), nodule dry weight plant-1 (4.576mg and 4.665gm at 60 DAS), relative leaf water content (85.10% and 87.53% at 90 DAS) and total chlorophyll content (1.715mg g-1 of fresh weight and 1.735 mg g-1 of fresh weight at 90 DAS), respectively. Among various nutrient treatments, the residual effect of 150% RDN application in kharif hybrid rice produced lentil crop with highest plant height (39.11cm and 40.60cm at 90 DAS), dry aerial biomass (131.88g m-2 and 1137.50g m-2 at 90 DAS), CGR (2.064g m-2 day-1 and 1.988g m-2 day-1 during 31-60 DAS), number of nodules plant-1 (32.93 and 34.66 AT 60 DAS), nodule dry weight plant-1 (4.642mg and 4.640gm at 60 DAS), relative leaf water content (85.01% and 87.87% at 90 DAS) and total chlorophyll content (1.755 mg g-1 of fresh weight and 1.778 mg g-1 of fresh weight at 90 DAS), respectively. Lentil grown under 25cm stubble height recorded higher plant height (38.43cm and 39.16cm at 90 DAS), dry aerial biomass (129.15 g m-2 and 134.10 g m-2 at 90 DAS), number of nodules plant-1 (30.53 and 32.91 at 60 DAS), nodule dry weight plant-1 (4.317 mg and 4.398 mg at 60 DAS) and relative leaf water content (84.07% and 86.87% at 90 DAS), respectively as compared to the crop under 15 cm stubble height. The N content N uptake (4.573%, 4.613% and 48.46 kg ha-1, 49.64 kg ha- 1), P content and P uptake (0.302%, 0.321% and 3.237 kg ha-1, 3.486 kg ha-1) and K content and K uptake (0.870%, 0.880% and 9.252 kg ha-1, 9.487 kg ha-1) of lentil seeds was found to be highest in lentil crops sown after harvesting of direct seeded rice in rabi 2020-21 and 2021-22, respectively. Irrespective of CEMs, lentil crop when grown after kharif hybrid rice that received 150% RDN recorded the highest N content and N uptake (4.652%, 4.680% and 48.34 kg ha-1, 49.82 kg ha-1), P content and P uptake (0.332%, 0.0.348% and 3.468 kg ha-1, 3.724 kg ha-1) and K content and K uptake (0.0.895%, 0.897% and 9.327 kg ha-1, 9.575 kg ha-1) of lentil seeds in rabi 2020-21 and 2021-22, respectively. Different stubble heights of hybrid rice, maintained during sowing of lentil crop in rabi season, resulted non-significant variation in seed and stover N, P and K content. The gross return from lentil cultivation was found to be the highest (₹62250 ha-1 and ₹62800 ha-1 in rabi 2020-21 and 2021-22, respectively) in plots which had direct- seeded hybrid rice cultivation with F3 treatment and finally leaving greater stubble height (25cm). The net return from lentil cultivation was also found to be the highest (₹33380 ha-1 and ₹33930 ha-1 in rabi 2020-21 and 2021-22, respectively) in plots which had direct-seeded hybrid rice cultivation with F3 treatment and finally leaving greater stubble height (25cm). Under the same growing environment, the B:C ratio was also found to be the highest (2.16 and 2.18 in rabi 2020-21 and 2021-22, respectively) for lentil cultivation. Results in respect of overall performance of rice-lentil system revealed that system productivity (8232.2 kg ha-1 and 8300.2 kg ha-1) and system production efficiency (34.30 kg ha-1 day-1 and 34.29 kg ha-1 day-1) attained highest values in transplanted rice- lentil system in 2020-21 and 2021-22, respectively. Rice-lentil system performed best when the kharif hybrid rice cultivation with 150% RDN was followed by lentil cultivation with regard to productivity (9750.6 kg ha-1 and 9800.6 kg ha-1), production efficiency (41.49 kg ha-1 day-1 and 41.10 kg ha-1 day-1) of the systems, N uptake (200.58 kg ha-1 and 206.59 kg ha-1), P uptake (42.25 kg ha-1 and 43.96 kg ha-1) and K uptake (181.64 kg ha-1 and 183.15 kg ha-1) in 2020-21 and 2021-22, respectively. Total population of bacteria (129.54×10-5 and 134.60×10-5 CFU g-1 dry soil), fungi (43.63×10-3 and 49.71×10-3 CFU g-1 dry soil) and actinomycetes (63.96×10-5 and 66.69×10-5 CFU g-1 dry soil) was highest at the end of direct seeded rice-lentil sequential cropping in 2020-21 and 2021-22, respectively. Cultivation of kharif hybrid rice with nutrient combinations of 50% RDN + 50% N through municipal compost + Azospirillum (F5 treatment) followed by lentil crop resulted higher total population of bacteria (1137.30×10-5 and 142.15×10-5 CFU g-1 dry soil), fungi (45.97×10-3 and 54.47×10-3 CFU g-1 dry soil), actinomycetes (66.52×10-5 and 69.91×10-5 CFU g-1 dry soil), OC (0.701% and 0.710%), available N (266.97 kg ha-1 and 271.12 kg ha-1), P2O5 (14.44 kg ha-1 and 13.56 kg ha-1) and K2O (120.12 kg ha-1 and 116.57 kg ha-1) in post-harvest soil during 2020-21 and 2021-22, respectively. The harvest of hybrid rice with a pre-determined stubble height, prior to sowing of lentil crop, exerted significant impact of microbial population in post-harvest soil at the end of rabi season. Total population of bacteria (128.18×10-5 and 131.68×10-5 CFU g-1 dry soil), fungi (41.62×10-3 and 48.03×10-3 CFU g-1 dry soil) and actinomycetes (62.12×10-5 and 65.21×10-5 CFU g-1 dry soil) was highest in rice-lentil system which consisted of lentil sowing under greater (25 cm) stubble height in 2020-21 and 2021-22, respectively. Based on 2-years data, the cost of cultivation of hybrid rice-lentil system was more (`128202 ha-1) when the system comprised of transplanted kharif hybrid rice cultivation with F5 treatment followed by lentil sowing under stubble height of either 15 cm or 25 cm in rabi season. This cropping system gave the highest gross return (`183020 ha-1 and `180510 ha-1 in 2020 and 2021, respectively) when it consisted of kharif hybrid rice cultivation under transplanted condition with F3 treatment followed by lentil sowing under greater (25 cm) stubble height in rabi season. The highest net return (`108206 ha-1) and B:C ratio (2.00) of rice-lentil system was obtained when it involved direct seeded hybrid rice cultivation kharif season with F3 treatment followed by lentil sowing under 25cm stubble height in 2020-21. But in 2021-22 net return (`113496 ha-1) and B:C ratio (2.04) of rice-lentil system was more when it involved direct seeded hybrid rice cultivation in kharif season with F3 treatment followed by lentil sowing under 15cm stubble height in rabi season. The available N gain was the highest (93.70 kg ha-1) under rice-lentil system which involved direct seeded hybrid rice cultivation with F4 treatment followed by lentil under 25 cm stubble heighten 2020-21 in rabi season. But in case of 2021-22 available N gain of rice-lentil system was more (97.37 kg ha-1) when the system consisted of transplanted kharif hybrid rice cultivation with F4 treatment followed by lentil sowing under 25 cm stubble height in rabi season. In 2020-21, the extent of P loss was low (5.97 kg ha-1) in rice-lentil system which involved transplanted hybrid rice cultivation in kharif season with F6 treatment followed by sowing of lentil crop under 25cm stubble height. But in case of 2021-22, the available P loss of rice-lentil system was low (5.99 kg ha-1) when the system comprised of transplanted kharif hybrid rice cultivation with F6 treatment followed by sowing of lentil crop under 25cm stubble height. The available K gain was maximum (114.57 kg ha-1) under rice-lentil system when it involved transplanted kharif hybrid rice cultivation with F6 treatment followed by rabi lentil sowing under 25 cm stubble height in 2020-21. But in case of 2021-22, available K gain of rice-lentil system was more (108.06 kg ha-1) when the system consisted of transplanted kharif hybrid rice cultivation with F2 treatment followed by lentil sowing under 25 cm stubble height in rabi season. Based on the above discussions, it was concluded that rice-lentil system, comprising directly sown hybrid rice receiving 150% RDF followed by sowing of lentil crop in winter under 25 cm left-over stubble height of hybrid rice, was superior over the same system with different treatment combinations. Therefore, rice-lentil system of cropping with above treatment combination can be prescribed for local farming community not only for getting higher system productivity but also for maintaining improved soil fertility status in the long run.
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    ThesisItemOpen Access
    In vitro direct regeneration and Agrobacterium rhizogenes-mediated hairy root culture for enhanced forskolin production in Indian coleus (Coleus forskohlii Briq.)
    (Department of Agricultural Biotechnology, Faculty of Agriculture, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur-741252, Nadia, West Bengal, 2022-11-21) Mitra, Monisha; Dr. Nirmal Mandal
    Coleus forskohlii is an herbaceous and aromatic plant belonging to the family Lamiaceae and order Lamiales having multifaceted uses namely in food industry, in cosmetic as well as in pharmaceutical arenas. The major metabolite found exclusively in the cork cells of the root is forskolin. Forskolin is used commercially for the treatment of glaucoma, asthma, and heart ailments. The major shortcoming faced in traditional cultivation of this plant is slow growth and incidence of pest and diseases mainly root rot caused by Macrophomina phaseolina. Furthermore, low metabolite concentration in the plants, and lower levels of forskolin is another limitation for its commercial uses. Considering all these aspects the present research has been proposed with the following two key objectives namely; 1) Establishment of in vitro propagation of Coleus forskohlii via direct regeneration approaches as well as their genetic fidelity assessment and 2) Establishment of Agrobacterium rhizogenes-mediated hairy root culture for enhanced forskolin production. Initial culture was established following a non-toxic, simple, and effective sterilization and then inoculated in basal MS medium fortified with different types and doses of single cytokinin, out of which MS medium augmented with 1.5 mg L-1 mT (meta Topolin) turned out to be promising since it displayed higher response (100% ±0.00), maximum number of shoots (12.66±1.20) and number of leaves (20±0.66) per inoculated shoot tip and also exhibited earliest response to shoot induction (5.33±0.33 days). In shoot proliferation experiment, the maximum number of shoots (12.66±0.66) along with highest number of leaves (23.66±0.88) was obtained when MS medium was supplemented with 1 mg L-1 mT + 0.05 mg L-1 NAA. The maximum number (19.33±1.76) and the length (4.76±0.38 cm) of healthy roots per plant were achieved on control medium (MS without PGRs). The sustainability of shoot regeneration ability was checked up to five subculture passages and meagre variability in terms of abnormalities like vitrification, malformation of shoots and yellowing was detected in the 5th subculture. In acclimatization experiment, the survival rate of plantlets cultured in a combination of vermiculite + sand was (91.00±0.57%). The concentration of photosynthetic pigments in plantlets during acclimatization (chlorophyll a, chlorophyll b, total chlorophyll and carotenoids) displayed a minimal increase in the first 10 days and then it increased rapidly and its maximum concentration was noted in the 30 days of acclimatization period. The micromorphological characterization of in vitro and ex vitro hardened plantlets on the basis of stomata and trichome revealed similarities in the features and it strengthened the proof towards the trueness of mother plant and the acclimatized plantlets. DNA fingerprinting of the in vitro-regenerated plantlets via analysis of inter simple sequence repeats (ISSRs) showed clonal fidelity of the plantlets with the mother plant. A stable transgenic hairy root (HR) culture has been developed using engineered three different types of Agrobacterium rhizogenes strains namely LBA1334 harbouring pCAM:2×35S:gusA binary vector; MTCC 532 and MTCC 2364, to achieve high yield of secondary metabolites. Putative transgenic HRs were observed in all the three strains. The highest transformation frequency (56.67±1.66%) was noted in internodal explants when immersed in A. rhizogenes suspension for 15 min and co-cultivated for three days. Putative transformation was confirmed by histochemical GUS staining assay that showed blue coloration in the transgenic HRs. This was further confirmed by PCR analysis of rolA, rolB, rolC and virD genes. Time course study revealed that the transgenic HRs grew rapidly in ½MS liquid medium with highest biomass production 0.464±0.0008 g per 50 mL DW after 42 days of culture. In the elicitor mediated experiment, when 20 mg L-1 methyl jasmonate was added to the 15 days old growing culture the biomass of HRs increased by 1.06-fold (DW=0.490±0.06 g). Histochemical localization through vanillin staining revealed the presence of forskolin and related terpenoids in the hairy roots since it displayed violet coloration in the cells. The forskolin content was compared among the transgenic HRs, in vivo as well as in vitro roots with the help of HPLC. The estimation revealed that there is 2.10 and 1.14 times increase in forskolin content in HRs (2.99±0.009 mg g-1 DW) in comparison to the amount accumulated in the in vivo (1.42±0.003 mg g-1 DW) and in vitro-grown (2.63±0.006 mg g-1 DW) roots, respectively. Addition of 20 mg L-1 methyl jasmonate to the 15 days old HR culture boosted the forskolin accumulation to the level of 5.42±0.007 mg g-1 DW, which was 1.8 times of the non elicitated HR culture, respectively. In addition, the content of several important phenolic and flavonoid compounds was increased in the transgenic HRs as analysed by spectrophotometer. The outcome of the present investigation shows great potential for a systematic and efficient in vitro direct regeneration system of plantlets and transgenic HR culture mediated enhanced forskolin accumulation that can serve as a substitute of conventional extraction technologies in order to provide resources of forskolin to the pharmaceutical industries.
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    ThesisItemOpen Access
    Soil biotic and abiotic factors influencing plant diseases in rice based cropping system with different regimes of conservation agricultural practices
    (Plant Pathology, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia – 741252, 2023-12-20) DASGUPTA AMRITA; Dr. Subrata Dutta
    Conservation agriculture (CA) aims to conserve, improve and make more efficient use of natural resources through integrated management of soil, water and biological resources combined with external fertilizer inputs. At early stage of CA there appear some serious issues related to supplying sufficient nutrients to the crops to achieve economically viable yields. These issues can be addressed by strengthening microbial interaction and optimizing soil biological activity through self-sustaining biological systems rather than reliance on external inputs or synthetic fertilizers. Modern agriculture is input and energy intensive and highly torturous in nature thus, becoming threats not only to microbial world but to whole ecology and environment. Thus, it is high time for the farmers and agriculturists to address the issues of environmental sustainability along with eco-friendly management practices for harnessing sustained crop productivity to ensure the future food security goal. Conservation agriculture (CA), offers low mechanical disturbance, crop rotation, retention of diverse crop residues and release of diversified chemical compounds as rhizo-depositions to soil and maintaining a protected, cozy habitat for microbes is well ahead biodynamic technology for sustainable crop production. Practices of CA are capable of regenerating and conserving top soil by restoring microbes, and ecosystem services and manage the disease dynamics in field crops under natural conditions. Scanty of literature has been available on the details of microbial population dynamics along with vis –a-vis plant disease dynamics under intensification of CA practices. In the current experiment, microbial dynamics, disease dynamics and yield was assessed and some of the important disease prediction models were developed under rice-wheat-green gram (R-W-G) and rice-mustard-black gram (R- M-B) cropping system under different degrees of CA practices. In the present study, it was observed that zero tillage was found to significantly increase the total bacterial, total fungal, total Actinomycetes and total Bacillus population, whereas, reduced tillage favoured the total phosphate solubilizing bacteria (PSB), total Pseudomonads population and nitrogen fixing bacterial (NFB) population. Real time (RT) PCR was performed to evaluate the population dynamics of Alphaproteobacteria, ii Betaproteobacteria and Gammaproteobacteria under three tillage different systems and it was found that intensification of CA practices favoured the Proteobacterial population dynamics, when compared to conventional tillage system. In the current study, dehydrogenase enzyme activity was also performed for better understanding of microbial enzyme activity under different tillage systems in combination with different nutrient- residues level. Zero tillage along with NR2 (100% residue + 50% RDF) performed the best, with highest enzyme activity in both the cropping system, proving effects of tillage systems and residue retention on microbial activity. Thus, a hypothesis that keystone microbial clads were well conserved in CA under microclimate created due to less soil disturbance, habitat restoration, cover cropping, crop rotation etc. ,is put forward. Population dynamics of Sclerotium rolfsii was evaluated along with the suppressiveness and conducivenesss of the soil under different regime of CA practices. In both the cropping systems (R-W-G & R-M-B), the maximum sclerotial population of Sclerotium rolfsii was observed in conventional tillage system as compared with CA practices. A meta-analysis was performed to assess the changes in microbial abundance under varying degrees of CA. Different tillage practices were the most important factors in defining the structure of bacterial communities and β-diversity matrix showed that reduced tillage (RT) and zero tillage (ZT) are closely related to each other whereas conventional tillage (CT) is distantly related to them, which is the reflection of management followed in these scenarios. Abundance at genus level showed that zero tillage and reduced tillage exhibited higher abundance of Bacillus when compared to conventional tillage. Streptomyces and Spingomonas showed similar kind of result, with maximum abundance in reduced tillage, followed by conventional tillage and zero tillage. Pseudomonas, on the other hand, showed maximum abundance in reduce tillage, followed by zero tillage and conventional tillage. The present study clearly demonstrated that the structure and diversity of soil bacteria in reduced tillage were significantly different compared with other tillage practices. Also the dynamics of naturally occurring plant diseases of rice (blast, brown spot, bacterial blight and sheath blight), wheat (leaf blight disease), green gram (Cercospora leaf spot disease), mustard (Alternaria blight and downy mildew) and black gram (Cercospora leaf spot disease) under rice-wheat-green gram and rice-mustard-blackgram cropping system were evaluated and it was observed that severity of some of the diseases are comparatively less with increasing intensity of CA practices and it was also observed iii that severity of the majority of rice diseases were less in reduced tillage system. Studies were also conducted for understanding the influence of different weather factors, micro- climatic variables and soil temperature on important diseases in R-W-G and R-M-B cropping system under varying degrees of CA practices. Disease prediction equations were developed based on 2 years data (2019-20 & 2020-2021) for few important diseases to understand the significant disease predicting weather and micro-climatic variables under different rgime off CA practices. In case of Cercospora leaf spot disease of green gram, different prediction models (multiple regression model, logistic regression model and canonical discriminant function model) had been compared and it was observed that canonical discriminant analysis model performed better in predicting the disease risk in comparison to other two models. Outcome of this study will be helpful to the farmers for adopting CA, particularly, in tropic and subtropical countries where agriculture is greatly relying on the benefits derived from plant–microbe interactions.
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    ThesisItemOpen Access
    IDENTIFICATION OF RICE GENOTYPES WITH ACCELERATING RECOVERY FROM PHOTOPROTECTION AND THEIR GENETIC ANALYSIS
    (GENETICS AND PLANT BREEDING, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia – 741252, 2023-12-20) Saha Shoumik; Dr. Somnath Bhattacharyya
    Rice cultivation in the eastern and north-eastern parts of India faces biotic and environmental challenges, including changing climatic conditions and extreme light fluctuations, which reduce crop yield potential by up to 35-40% in Kharif. The plant undergoes photoprotection mode by increasing nonphotochemical quenching (NPQ) in high light intensity (>1200 μmole m-2s-1 PPFD ), which attenuates photosystem II yield (ɸPSII) drastically. The plant remains in photoprotection mode (reduced ɸPSII and high NPQ) even after light intensity becomes normal (<1000 PPFD) for a more extended period (usually > half an hour). The study aims to identify rice genotypes with quick photoprotection recovery (QPR) ability and allelic variations of the genes controlling the traits. However, phenotyping QPR requires more than forty-five minutes/genotype to measure the chlorophyll fluorescence parameters in progressive actinic light (200-1800 μmole m-2s-1 PPFD) after dark adaptation. Swarnaprabha, Shatabdi, GB1, and Bidhan Suruchi showed QPR ability as observed from the less gap between theoretical and observed ɸPSII yield at 400 PPFD as well as a larger difference between NPQ1800 -NPQ400 after twenty minutes of exposure at six different increasing PPFD, whereas Swarna, Chotogora, and Srabani behave contrarily. The study finds that instantly (2 minutes) measured A400/A1800 ratio in 8-10 days old flag leaves strongly associated with NPQ1800 -NPQ400 and ɸPSII400- ɸPSII1800 with R2 value 0.81 and 0.77 respectively. In a panel of ninety-six genotypes using the QPR data by the newly proposed methodology and 7K SNP genotyping data, GWAS identified that the region (LOD>3) possesses the genes reported earlier for photoprotection recovery in rice and other plants. QTL analysis further validated new methodology in a RIL population developed from a contrasting parental pair Swarnaprabha x IR64. The GWAS and QTL analyze the regions carrying known photoprotection-related genes like OsPsbS1, OsLUT2, OsVDE, OsZEP, OsPGPL2, OsbZIP72 located on chromosomes 1, 4, 8, 9. Genotypes with quick photoprotection recovery identified and further analyzed with existing methodology confirmed their QPR ability. A positive association between A400/A1800 ratio and yield and biomass was observed in RIL with R2 values of 0.11 and 0.17, respectively. The newly identified methodology for the QPR will be used for easier introgression of the traits in popular cultivars of the zone. The identified genotypes, genes, and QTLs can be used to improve yield potential and allele mining.
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    ThesisItemOpen Access
    In vitro mass propagation, polyploidization, and elicitor-mediated enhancement of vincristine production in Catharanthus roseus (L.) G. Don
    (GENETICS AND PLANT BREEDING, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia – 741252, 2023-12-20) Das Anamika; Dr. Sutanu Sarkar
    Catharanthus roseus, often known as Madagascar periwinkle or periwinkle, is a species of flowering and medicinal plant that belongs to the family Apocynaceae, having chromosome number 2n=16. The two most common cultivars of C. roseus are "rosea" with pink flowers and "alba" with white flowers. One of the major alkaloids, vincristine, which has anti-cancerous activity, is present in very small amounts (around 0.0005% of total alkaloids) in the leaves of C. roseus. Vincristine has proven to be a highly effective drug in the chemotherapy of various kinds of cancer including both paediatric and adult acute lymphoblastic leukaemia, neuroblastoma, Wilkins' tumour, Hodgkin's disease, and reticulum cell sarcoma. Since vincristine is particularly demanded yet difficult to extract, there is a continuing effort to improve the production of this dimeric alkaloid. Traditional seed propagation limitations affecting secondary metabolite production include low germination rates, low seed viability and vigour, etc. Moreover, spontaneous outcrossing results in genetic changes that alter the quantity and quality of beneficial alkaloids including vincristine. Taking all of these factors into account, the current study has been conducted with the aim of developing an in vitro methodology for high vincristine cultivar among alba and rosea, and further vincristine enhancement using biotechnological approaches such as in vitro polyploidization and elicitation. HPTLC analysis for the vincristine content of both cultivars showed that the C. roseus cv. rosea had considerably higher vincristine (1025.69±0.76 μg g-1 DW) at three months of age than the C. roseus cv. alba (939.23 ± 0.42 μg g-1 DW). The initial culture of C. roseus cv. rosea was established by using apical shoot tips as explants and following an effective surface disinfection method. For direct regeneration, the in vitro shoot tips were inoculated on MS medium fortified with different types and doses of cytokinin alone, out of which MS medium supplemented with 0.5 mg L-1 mT emerged as promising since it showed the highest number of shoots (10.9±0.23) per inoculated shoot tip. However, the addition of 0.1 mg L-1 NAA to the MS medium supplemented with 0.5 mg L-1 mT increased the number of shoots (12.67±0.67) in the shoot proliferation experiment. The maximum number (21.9±1.85) of roots with the maximum length (39.2±1.65 mm) were reported on half-strength MS medium supplemented with 0.5 mg L-1 IBA. For indirect regeneration, in vitro leaves were used as explants for callus induction. Among various auxins used, the maximum response percentage (97.5±0.50%) to callus induction with earliest (4.7±0.15 days) induction and highest biomass (159.8±0.59 mg fresh weight, 29.6±0.16 mg dry weight) was achieved on MS medium supplemented with 1 mg L-1 Picloram. Organogenic calli were found to be inducing a maximum number of shoots (9.00±0.57) on MS medium supplemented with 1.5 mg L-1 BA in conjugation with 0.2 mg L-1 NAA, with a response percentage (52.66±1.52%). Among the various planting substrates investigated in combination, cocopeat and vermiculite showed the highest survival percentage (99.0±1.00%) in the acclimatisation experiment. The clonal fidelity of in vitro-regenerated plantlets to the mother plant was demonstrated by the DNA fingerprinting of the plantlets using ISSR primers. In order to induce in vitro polyploidization, shoot tips from the already formed multiple shoot cultures were immersed in different doses of colchicine solution for diverse amounts of time. The maximum rate of polyploidy induction (40.00%) was achieved during a 12-hour treatment with a 0.1% colchicine solution. The cytological study revealed that putative polyploids had a combination of diploid and tetraploid cells, which was further supported by FCM. Vincristine concentration was reported to be 1.49 times higher in colchicine- induced mixoploid (2348.85±0.60 μg g-1 DW) acclimatised plants compared to in vitro diploids (1577.22±0.67 μg g-1 DW) and about 2.29 times higher compared to the in vivo mother plant after treatment with a 0.1% colchicine solution for 12 hours. On the elicitor-supplemented media, the shoot tips from the multiple shoot culture and the induced calli from the in vitro leaves were injected. After 12 weeks of culture, it was shown that the shoot tip cultures on the medium supplemented with 50 mM AgNO3 had greater vincristine levels (2228.72±0.92 μg g-1 DW) than the control (1178.59 ± 0.87 μg g-1 DW), which is over 1.89 times higher than the control and 2.17 times higher than the in vivo mother plant. The calli on 50 M SA supplemented medium were also shown to have more vincristine (302.67 ± 1.45 μg g-1 DW) among elicited calli after 6 weeks of culture, however the non-elicited calli did not exhibit a peak for vincristine in HPTLC analysis. The findings of this study indicate great promise for a precise and effective in vitro direct and indirect regeneration system, elicitor-mediated enhanced vincristine production in C. roseus. Also, in vitro induction of polyploidy was attempted for the first time in C. roseus, which resulted in mixoploids with higher vincristine content. These findings can be employed as an addition to the current extraction techniques and as a source of vincristine for the pharmaceutical sectors.
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    ThesisItemOpen Access
    VULNERABILITY AND ADAPTIVE RESPONSE OF FARMING COMMUNITY TO CLIMATE CHANGE IN HILLY AND TERAI AGRO-CLIMATIC REGIONS OF WEST BENGAL
    (AGRICULTURAL EXTENSION, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia – 741252, 2023-12-20) DUTTA SUCHANDRA; Dr.Tapan Kumar Mandal
    Climate change poses significant challenges to agricultural communities, particularly in regions with diverse agro-climatic zones like West Bengal, India. This study aims to assess the vulnerability of farming communities and explore their adaptive responses to climate change in the Hilly and Terai agro-climatic regions of West Bengal. This study was conducted at household level. ‘Descriptive and Diagnostic’ research design was used. Out of 8 Community Development blocks of hilly agro-climatic region of West Bengal, 3 blocks were randomly selected. For terai agro-climatic region, 9 blocks out of 32 were randomly selected. Thus, a total of 12 blocks were selected for the present study. Following that, two villages from each block were chosen at random. 15 responders were chosen at random from each village. Primary data were collected from respondents who were mixed farmers engaged in multiple types of agricultural activities, such as crop cultivation, livestock rearing and fishery. As a result, 360 respondents were chosen for the study employing the personal interview method, observation methods, and appropriate PRA tools. The trend analysis of temperature and rainfall provide some valuable insights. The overall annual rainfall of hilly region for the study period (1981-2020) was found to be decreasing about 9.61mm/year whereas the overall annual rainfall of terai region for the study period (1981-2020) was found to be increasing about 4.12 mm/year. The maximum annual temperature of hilly region for the study period (1981-2020) was found to be decreasing about 0.003 °C/year whereas the mean and minimum annual temperature of hilly region increases significantly by 0.018°C/year and 0.039°C/year respectively. On the other hand, the maximum, mean and minimum annual temperature of terai region for the study period (1981-2020) was found to be significantly increasing about 0.0104°C/year, 0.023°C/year and 0.035°C/year respectively. The rainfall perceptions of hilly and terai farming communities align with the actual trends of the last 10 years, showing an increasing trend in annual rainfall in both regions. However, their perceptions about summer temperature differ from recorded data, while their perceptions about winter temperature align with the actual trends of the past decade. The farming community of both the region differ much in their feelings towards the perceived economic and environmental impact of climate change on agriculture whereas they do not differ much in their feelings towards the perceived social impact of climate change on agriculture. Though the difference between two agro-climatic regions of West Bengal in exposure was very small but the sensitivity was very high followed by the adaptive capacity of the farming community which in turn results in very large vulnerability difference in hilly and terai regions. A total of 33 and 32 adaptive responses were identified in hilly and terai regions respectively, to cope up with climate change in the field of crop cultivation, livestock rearing and fisheries. The effectiveness of adaptive responses in crop cultivation varies by region. In the hilly region, ‘Using indigenous technological knowledge to combat biotic and abiotic stresses’ is effective, while in the terai region, ‘Practicing ridge and furrow method for potato and chili cultivation’ and ‘Shifting the sowing and harvesting time of crops’ are effective. In livestock rearing, ‘Vaccination against diseases’ is effective in the hilly region, while ‘Rearing indigenous and non-descriptive breeds of ruminants’ is effective in the terai region. Additionally, ‘Practicing Composite fish farming’ is effective in both regions. The study identifies the household level vulnerability of both regions and underscores the need for region-specific and context-sensitive policies that promote climate-resilient agriculture and strengthen the adaptive capacity of farming communities.
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    ThesisItemOpen Access
    EPIDEMIOLOGY AND MANAGEMENT OF LENTIL DISEASES WITH SPECIAL REFERENCE TO COLLAR ROT DISEASE IN LOWER GANGETIC PLAINS OF WEST BENGAL
    (PLANT PATHOLOGY, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia – 741252, 2023-12-20) NAZNEEN HUMA; Dr. Raju Das
    Lentil is one of the oldest known protein-rich grain legumes in the winter cropping system of Indo-Gangetic plains including lower Gangetic Bengal (LGB) and provides a balanced diet with high nutritional value. Lentil productivity in this zone is seriously impeded due to the prevalence of several biotic stresses. Collar rot, lentil blight complex (LBC) and rust are major problems for lentil not only in Eastern India, but throughout the South Asia. Collar rot disease incited by Sclerotium rolfsii Sacc. is one of the most dreaded soil borne diseases of lentil and is found to cause yield losses of up to 50% in the farmer’s field (Asghar et al., 2018). Most importantly there is no resistant genotype of the lentil crop against collar rot disease and chemical control is not also effective against this soil borne disease. In the present investigation, a comprehensive effort has been made to study the disease situation of different diseases of lentil under lower Gangetic plains of West Bengal; screening and identifying promising stable tolerant lentil genotypes against major diseases of lentil under field conditions, developing a forewarning model for successful prediction of collar rot disease and development of biorational management package utilizing plant extracts, bioagents, inducers and chemical fungicides for efficient eco-friendly management of S. rolfsii inciting collar rot disease of lentil. Thus, taking a holistic view on all these aspects, an intensive survey was conducted in major lentil growing districts of West Bengal, viz. Nadia, North 24 Paraganas, Malda and Murshidabad in the months of November–March (2018-19, 2019-20 and 2020–21).The present survey study reflected that lentil fields were infected with three main fungal diseases: Collar rot (Sclerotium rolfsii), lentil blight complex (LBC) and rust (Uromyces viciae-fabae) disease. Collar rot and LBC were the most widespread, while lentil rust occurred little comparatively to both diseases. There was no individual occurrence of either Alternaria or Stemphylium blight rather mixed infection was obtained in a complex manner. To the best of our knowledge, this is the first report of mixed infection of A. alternata and S. botryosum in a complex manner followed by successful isolation of S. botyrosum and confirmation of the pathogens by sequencing through ITS and Stemphylium specific gpd1 and gpd2 primers. Higher disease response was observed in normal sown fields for collar rot disease whereas for lentil blight and rust, the highest disease severity was observed in late sown fields. Ensuring lentil planting during the second fortnight of November can mitigate the climate mediated disease risk. Soil texture played a significant role in the collar rot development, viii more pronounced in light textured soil. Intercropping with mustard and okra individually considerably reduced the DI for collar rot disease as compared to other intercropping patterns. For collar rot disease, ILL-10802 was observed as highly tolerant with only 2% DI and HUL-57 as highly susceptible with 34.7% DI. For blight and rust diseases, the highly tolerant varieties were Pusa ageti (DS 5.4%) and IPL-526 (DS 3.2%) respectively, whereas local varieties were susceptible to both diseases. Screening of lentil genotypes for resistance against collar rot (Sclerotium rolfsii) reflected that the effect of genotype, environment and the genotype environment interaction (GEI) were significant among the tested lentil genotypes albeit G (genotypes) found to exert a greater effect compared to the environment in this variation. Among the locations, the highest mean collar rot disease incidence irrespective of genotypes (including check) over 3 years was observed in Chakdah location (19.18%) followed by Kalyani location (16.46%), whereas the lowest mean incidence was observed in Sekhampur location (13.84%). Amid the genotypes, the significantly lowest average collar rot disease incidence (2.26%) was observed in WBL-58 followed by IPL-603, PL-254, X2012S-186-S20 and TCADL-18-2. From the GGE biplot for resistance against collar rot (Sclerotium rolfsii), PL-254 was considered as the "ideal" genotype and WBL-58 and IPL-603 were recognized as "desirable" genotypes with coherent response over the tested locations. Over the years, Sekhampur location displayed closest angle with "AEC abscissa," than the other 2 locations thus being identified as "representative". Therefore, Sekhampur location with the highest desirability index (4.264) was considered as the “ideal location” for screening against collar rot in lentil. Chakdah location and Sekhampur location were grouped in upper mega environment and Kalyani location during both the years grouped in the lower mega environment. In upper mega environment ME- I, IPL-603 was the only best performing genotype and in ME- II, WBL-58 and X2012S-186-S20 were the winning genotypes but in comparison to X2012S-186-S20, WBL-58 genotype exhibited high stability. Screening of lentil genotypes for resistance against lentil blight complex (LBC) (Alternaria/Stemphylium) reflected that the effect of genotype, environment and the genotype environment interaction (GEI) were significant among the tested lentil genotypes although, G (genotypes) contributed higher in comparison to the environment in this total variation. Among the locations, the highest mean LBC disease severity irrespective of genotypes (including check) over 3 years was observed in Chakdah (23.84%) followed by Kalyani ix (20.08%), whereas the lowest mean severity was observed in Sekhampur (16.08%). Amid the genotypes, the significantly lowest average LBC disease severity (9.49%) was observed in IPL-239 followed by PL-7, DPL-62, TCADL-19-5 and BCL-1296. From the GGE biplot for resistance against lentil blight complex (LBC) (Alternaria/Stemphylium), DPL-62 was the "ideal" genotype and TCADL-19-5 followed by BCL-1296 were recognized as "desirable" genotypes. Kalyani location with the highest desirability index (4.252) was considered as the "ideal" location for screening against LBC disease severity in lentil. Stepwise multiple regression analysis (MRA) and canonical discriminate model could predict only 51.9% and 71.7% respectively of the variations of S. rolfsii disease incidence. Among the different prediction models, Binary logistic regression model was found to be the most sensitive model and successfully predicted 77.8% of disease risk and no-risk periods in the testing data set. Among the thirteen soil abiotic factors and weather variables examined, ((Soil TM(5cm), Soil TM(15cm), Soil TM(30cm), Soil TE(5cm) and Soil TE(30cm)) were found to be the significant parameters in predicting disease occurrence in the binary logistic regression model. Biochemical parameters phenol, antioxidant enzymes PPO, PAL and SOD were found to be significantly negatively correlated with collar rot disease incidence indicating that these enzyme activities might play a major role in attributing resistance towards host-pathogen interactions. In the field experiment, it was observed that the seed and soil treatment with microbial consortia (GP8: Pseudomonas aeruginosa and B11: Bacillus subtilis) and conjoint application of chitosan (seed treatment) and Ageratum plant extract (soil drenching) checked both pre and post emergence damping off/ collar rot disease of lentil and enhanced the yield of lentil. Thus, this bio-intensive disease management package may in the future be used in a large scale in this zone for cheap and eco-friendly management of soil borne diseases in different cropping systems.
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    ThesisItemOpen Access
    Characterization of spot blotch of wheat pathogen and defining their mechanism of resistance or susceptibility in wheat
    (Plant Pathology, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia – 741252, 2023-12-20) CHAKRABORTY SUNANDA; Dr. Sunita Mahapatra
    Wheat (Triticum aestivum L.) is a dominant staple crop cultivated in an area of around 215 million hectares, across wide range of latitudes covering around 89 countries of the world. Out of the total global area under wheat cover, an estimated 25 million ha is infected by spot blotch disease of which 40% is India’s share. Considering the importance of the pathogen under West Bengal conditions, the following objectives for the research work was formulated: 1) Identification and characterization of fungi associated with spot blotch of wheat and their pathogenecity assessment on host 2) Determination and correlation of ecological and phenological factors responsible for occurrence and host preference of spot blotch pathogen and 3) Determination of resistance in different wheat varieties and relative susceptibility to spot blotch disease. The roving survey conducted in Nadia and Murshidabad revealed that the disease severity ranged from 44.03% to 81.48% and the highest disease severity (DLA%) was observed in Domkol-Taraf (81.48%), while the lowest value was observed in Ghaat more, Krishnanagar - Karimpur route (44.03%). Among the twelve isolates of Bipolaris sorokiniana collected from the locations, BSC11 was found to be most aggressive, based on Percent Disease Index, Incubation Period, Latent Period and Lesion size. The disease severity, observed in spot blotch susceptible genotype K 1317, was positively correlated with number of spores, growth rate of mycelium and lesion size, whereas, length of the spore, incubation period, latent period were negatively correlated with disease severity. The molecular characterization of the twelve isolates with ITS1/ITS4 primer pair produced amplified product at ~600bp. For assessment of ecological and phenological factors responsible for occurrence and host preference of spot blotch pathogen, leaf tip necrosis (LTN), lesion mimic (Lm), lesion size (LS), lesion type (LT), leaf angle (LA) and chlorophyll content was evaluated on fifty wheat genotypes during the rabi season of 2020-21, 2021-22 and 2022-23. It was observed that with increase in Lm, LT, LS and LA, there is a significant increase in Disease Leaf Area, whereas with increase in LTN and Area Under SPAD value Decline Curve, Disease Leaf Area was significantly decreased. It indicated that Plants with leaf tip necrosis, higher chlorophyll, erect leaves, without lesion mimic, and smaller lesion lesion size might be chosen for tolerance to spot blotch. Field screening of wheat genotypes conducted during the rabi season of 2020-21, 2021-22 and 2022-23 revealed that the genotypes DBW 252, DBW 386, PBW 899, PBW 897, HI 1612, HI 1653, HD 3086, HD 3293, DBW 187 showed resistant reaction. Whereas, the genotypes DBW 303, PBW 644, PBW 771, PBW 872, PBW 887, PBW 891, PBW 893, HI 1654, HI 1674, HI 1675, HD 2932, HD 2967, HD 3369, HD 3385, HD 3470, HD 3471, GW 538, GW 542, WH 1402, CG 1036, UP 3102, MACS 4100, MACS 6814, NIAW 3170, JKW 261, MP 3557 showed moderately resistant reaction. Similarly, the genotypes DBW 380, GW 322, GW 547, WH 1311, CG 1040, recorded moderately susceptible disease reaction and DBW 398, PBW 889, GW 513, GW 543, UP 3111, UAS 3080, LOK 79, K 1317, Raj 4083 recorded susceptible reaction among the 50 genotypes screened. The analysis of yield attributes revealed that Maximum Panicle Length was obtained in PBW 897, PBW 899, PBW 889, HD 3293,GW 513, NIAW 3170, whereas, minimum value was observed in Raj 4083, followed by HD 3471. Maximum number of grains per panicle was noticed in PBW 897, HI 1653, HD 3086, DBW 252, and minimum in Raj 4083, followed by MACS 6814 and WH 1311. Maximum Thousand Grain Weight was noticed in DBW 252, PBW 893, HI 1653, whereas minimum thousand grain weight was recorded in GW 543, HD 3086 and HD 3293. Biochemical characterization was conducted considering total phenol content, Polyphenol oxidase activity and Phenylalanine ammonia lyase activity at different intervals. A significant negative correlation was observed between Diseased Leaf Area with Phenol content at 24 hours after inoculation (hai), Phenol content at 48 hai, Phenol at 72 hai, PPO activity at 7 days after inoculation (dai), PPO activity at 15 dai, Phenylalanine Ammonia Lyase activity at 0, 24, 48 and 72 hai. Molecular characterization of nineteen genotypes was done from the fifty genotypes collected. Twelve SSR primers were taken for assessment, out of which six primers, i.e., Xgwm148 (200bp), Xgwm374 (200 bp), Xgwm295 (220 bp), XWGGC7412 (70 bp), Wmc335 (140 bp) and Xgwm425 (100 bp), exhibited polymorphism. Among the genotypes, PBW 897 exhibited resistance reaction as well as positive reaction with the primers, except primer Xgwm 425. Among the primers, three primers Xgwm374, Xgwm295 and Xgwm425 exhibited signification reaction when assessed in the genotypes on the basis of Diseased Leaf Area (DLA%). The isolates of Bipolaris sorokiniana collected in this study can be further subjected to diversity analysis using specific SSR markers. The outcome of the present investigation may be utilised further for selection of genotypes for resistance breeding against spot blotch of wheat at field as well as molecular levels.
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    ThesisItemOpen Access
    Development of genetic and genomic resources for Downy mildew resistance and low ODAP content in Lathyrus sativus L.
    (Agricultural Biotechnology, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia – 741252, 2023-12-20) Saha Pratik; Dr. Md. Nasim Ali
    Grasspea (Lathyrus sativus L.) belongs to the family Fabaceae and the tribe Vicieae having chromosome number (2n = 2x = 14). India is the largest producer of lathyrus which is the third most important pulse crop after chickpea and pigeon pea. It is one of the most important climate resilient crops which thrive well not only in extreme weather and stressed condition but also in poor soil. It is a good source of dietary proteins and is used as food and fodder including improvement of soil fertility. The cultivation of this crop is neglected due to the presence of anti-nutritional compound β-N-oxalylamino-L-alanine (BOAA) or β-N- oxalyl-L-α, β-diaminopropionic acid (ODAP) which is considered as causative agent of the disease Lathyrism, the paralytic disorder. In recent past, many breeders started working to develop low-ODAP lines like Ratan, Prateek and BioL-212 etc. containing ~ 0.2% ODAP. Among different biotic factors, downy mildew (Peronospora lathi-palustris) poses a serious threat in case of water stagnation during winter rains. On the other hand, introgression of disease resistance gene leading to increase yield has also been initiated in grasspea using marker assisted selection. Therefore, it is necessary to develop trait linked molecular markers for marker assisted breeding for developing new Lathyrus varieties. The present work was aimed to screen out the segregants, from F2 and F3 population derived from two different cross combination, Berhampore local x Mahateora and Mahateora x BioL-212 attributed with high grain yield coupled with zero/negligible ODAP content and resistance to downy mildew resistance. In the present study, the segregating population (F2 and F3) developed from two sets of crosses (Mahateora x BIO L-212 and Berhampore Local x Mahateora) were characterized. Simple Sequence Repeats (SSR) marker-based assessment was done for parents and segregating populations in search of trait associated marker and to deduce molecular diversity. A total of 120 SSR markers including 30 EST-SSR were used for molecular diversity and screening for association with ODAP and /or Downey mildew. All morphometric traits were statistically significant in segregating populations derived from both the parental crosses. Based on the mean seed yield plant-1, the F2 segregants MBiF2-1, MBiF2-2 MBiF2-4 and three F3 Segregants MBiF3-43, MBiF3-54, and MBiF3-52 from Mahateora x BioL-212 as well as from Berhampore Local x Mahateora, F2 segregants BLMF2-23, BLMF2-37 and BLMF2-50 and F3 segregants BLMF3-46, BLMF3-143 and BLMF3-100 were found very promising. Low ODAP content (≤0.1%) was found in BLMF3- 32, BLMF3-78, BLMF3-8, BLMF3-186, BLMF3-39, BLMF3-46 and BLMF3-211. With respect to the percent disease incidence (PDI), the identified resistant segregants to Downy mildew were BLMF3-128 (2%), BLMF3-8 (4%), BLMF3-36, (12%) BLMF3-39 (12%), BLMF3-195 (14%) and BLMF3-100 (18%). The PDI was highest in BLMF3-38 (44%). Based on highest seed yield/plant (>20 g), low ODAP (≤0.1%) and PDI (<12%), the most promising segregants identified were BLMF3-39, BLMF3100, BLMF3211, BLMF3168. The seed yield/plant were found to be significantly and positively correlated at both genotypic and phenotypic level with Plant height, number of branches plant-1, number of pods plant-1, pod length, number of internodes plant-1 and number of seeds pod-1. The Regression model identified number of pod plant-1, 100 seed weight, number of seeds pod-1 and pod length in F2 of the crosses where as in the F3 population of Berhampore Local x Mahateora, number of pods plant-1, number of seeds pod-1, number of internodes plant-1, 100 seed weight, plant height and number of branches plant-1 were considered as the better explanatory variables. No significant differences between GCV and PCV were found for most of the traits, indicating lesser influences of environmental factors. High heritability coupled with high Genetic advance over mean for plant height, number of branches plant-1, number of pods plant-1, and seed yield plant-1 were recorded to be used for indirect phenotypic selection. Multivariate analysis based on morphometric parameters from the segregants from Mahateora x Bio L-212 viz, MBiF2-49, 2, 4, 55, 46, 20, 11, 19, 52, 33, 25 and MBiF3-52; from Berhampore Local X Mahateora the segregants BLMF2-27, 56, 30, 37, 50, 59 and, BLMF3-128, 143, 46, 211, 100, 168 and 39 were found as the diverged genotypes. Molecular diversity based on SSR genotyping formed 7 distinct groups where Cluster V was found to be the largest with 15 cluster members. Based on higher Polymorphic Information Content (PIC) and Marker Index (MI) value, the SSRs namely c39279_g1_i12, c46049_g2_i1, c34810_g1_i1, c35787_g1_i1, c43114_g1_i1, c46949_g2_i1, c13442_gi_i1 and S-168 could be used in molecular diversity analysis in lathyrus for future breeding programme. From the study, the EST-SSR marker c31994_g1_i1 and c35336_g1_i4 were found putatively associated with low ODAP content from both F2 and F3 population. In the F3 population c39249_g1_i1 and S-159 showed association with downy mildew resistance.