Loading...
Dr. Rajendra Prasad Central Agricultural University, Pusa
In the imperial Gazetteer of India 1878, Pusa was recorded as a government estate of about 1350 acres in Darbhanba. It was acquired by East India Company for running a stud farm to supply better breed of horses mainly for the army. Frequent incidence of glanders disease (swelling of glands), mostly affecting the valuable imported bloodstock made the civil veterinary department to shift the entire stock out of Pusa. A British tobacco concern Beg Sutherland & co. got the estate on lease but it also left in 1897 abandoning the government estate of Pusa.
Lord Mayo, The Viceroy and Governor General, had been repeatedly trying to get through his proposal for setting up a directorate general of Agriculture that would take care of the soil and its productivity, formulate newer techniques of cultivation, improve the quality of seeds and livestock and also arrange for imparting agricultural education. The government of India had invited a British expert. Dr. J. A. Voelcker who had submitted as report on the development of Indian agriculture. As a follow-up action, three experts in different fields were appointed for the first time during 1885 to 1895 namely, agricultural chemist (Dr. J. W. Leafer), cryptogamic botanist (Dr. R. A. Butler) and entomologist (Dr. H. Maxwell Lefroy) with headquarters at Dehradun (U.P.) in the forest Research Institute complex.
Surprisingly, until now Pusa, which was destined to become the centre of agricultural revolution in the country, was lying as before an abandoned government estate. In 1898. Lord Curzon took over as the viceroy. A widely traveled person and an administrator, he salvaged out the earlier proposal and got London’s approval for the appointment of the inspector General of Agriculture to which the first incumbent Mr. J. Mollison (Dy. Director of Agriculture, Bombay) joined in 1901 with headquarters at Nagpur
The then government of Bengal had mooted in 1902 a proposal to the centre for setting up a model cattle farm for improving the dilapidated condition of the livestock at Pusa estate where plenty of land, water and feed would be available, and with Mr. Mollison’s support this was accepted in principle. Around Pusa, there were many British planters and also an indigo research centre Dalsing Sarai (near Pusa). Mr. Mollison’s visits to this mini British kingdom and his strong recommendations. In favour of Pusa as the most ideal place for the Bengal government project obviously caught the attention for the viceroy.
Browse
Search Results
ThesisItem Open Access SELECTION OF ELITE EARLY MATURING SUGARCANE CLONE AND THEIR MOLECULAR CHACTERIZATION(RPCAU, Pusa, 2023) DASH, CHANDAN KUMAR; Kumar, BalwantThe current study entitled “Selection of elite early maturing sugarcane clones and their molecular characterization” conducted during the year 2022-23 at Research Farm, R.P.C.A.U., Pusa, Bihar with seventeen sugarcane clones in randomized block design with two replications was to select elite genotypes through assessment of variability, association among characters, and the effects of attributing traits on cane yield. Molecular characterizations were performed using SSR markers to complement our understanding on sugarcane genetic diversity. Sixteen traits were recorded, including germination percentage at 45 days, plant height at harvest, cane diameter at harvest, brix % and pol % in juice at 8 and 10 months stages, purity % at 8 and 10 months stages, extraction % at harvest, single cane weight, number of shoots at 120 DAP, number of millable cane at harvest, cane yield, and CCS (t/ha). The analysis of variance indicated significant variation among the sugarcane clones for all sixteen traits, highlighting their potential for improvement. Clones X 20034, CoX 20069 and CoX 20246 exhibited superior performance for most of the traits, including cane yield. Phenotypic variance was higher than genotypic variance for all traits, indicating the influence of environmental factors. Heritability estimates were high for most of the traits. Besides high heritability, traits such as single cane weight and number of millable cane showed the highest genetic advance, suggesting simple phenotype selection for improvement of these traits. Correlation analysis revealed several traits had highly significant positive associations with cane yield, such as germination % at 45 DAP, plant height at harvest, number of millable cane at harvest, and CCS (t/ha). Further path coefficient analysis showed the direct and indirect effects of these traits on cane yield, with CCS (t/ha) having the highest positive direct effect while brix % at 10 months stage showing the highest negative direct effect. Genetic characterization using SSR markers demonstrated a substantial level of genetic diversity among the seventeen sugarcane clones, enabling unique genotyping. The markers showed 123 allelic variations, with an average of 7.23 alleles per primer, and primer pairs NKS 1, NKS 34, NKS 57, and NKS 61 displayed a higher number of alleles. The PIC values ranged from 0.63 to 0.92, indicating the genotypes' allelic diversity and frequency. The study employed a selection procedure based on pooled ranking of sucrose % in juice at 10 months stage and cane yield, along with natural disease tolerance, insect infestation, and morphological appearance. Based on ranking of cane yield and sucrose % three genotypes namely CoX 20398, CoX 2069 and CoX 20164 were selected as elite early maturing clones with tolerance against natural incidence of diseases and pests. These elite early maturing clones will be helpful in further breeding programme.ThesisItem Open Access AGRO-MORPHOLOGICAL EVALUATION AND MOLECULAR CHARACTERIZATION FOR GRAIN ZINC CONCENTRATION OF RICE GENOTYPES(RPCAU, Pusa, 2023) RS, ASWATHY NAIR; NilanjayaThe present investigation was undertaken with thirty five rice genotype which were presumed to be biofortified to study the variability and genetic parameter in addition to character association, path effects for yield and quality parameter, genetic divergence study among the genotypes and to evaluate genetic diversity in grain Zinc content using microsatellite spanning primers in the representative population. This study involved ten quantitative characters viz. Plant height, Panicle length, Days to 50% flowering, Days to physiological maturity, No: of panicles per plant, Spikelet fertility, 1000 grain weight, No: of grains per panicle, Zinc content in rice grains, Grain yield per plant. The results have revealed high phenotypic and genotypic coefficient of variation for Grains per panicle, high heritability coupled with genetic advance as per cent of mean for traits like plant height, Days to 50% flowering, Days to physiological maturity, No. of panicles per plant, spikelet fertility,1000 grain weight, No. of grains per panicle, zinc content in rice grains, grain yield per plant. The results of character association revealed that No. of panicles per plant, Spikelet fertility, No. of grains per panicle and 1000 grain weight were positively and significantly associated with grain yield per plant. So indirect selection of these trait would be fruitful. Path coefficient analysis showed that traits like No. of panicles per plant, Spikelet fertility, No. of grains per panicle, 1000 grain weight, and zinc content in rice grains exhibited positive direct effects on grain yield per plant indicating the effectiveness of these traits in improvement of grain yield per plant towards development of high yielding genotypes with good nutritional quality. The current study assess genetic diversity and to determine the Zn value by Atomic absorption spectrometry. Zinco rice and R-RGY-MH-113 had highest zinc value of respectively. Based on the tocher method shown that the total genotypes are clustered into nine clusters in which cluster IV had the maximum genotypes followed by cluster I and cluster II. The inter cluster distance, the maximum inter cluster distance was observed between cluster VIII and cluster IX followed by cluster V and cluster IX. Therefore, it was concluded that diverged genotypes from these groups can be utilized as better parents for future breeding programmes. Thirteen microsatellite spanning primers were used for the amplification. Except OsYSL6K all the other primers resulted in successful amplification. A total of 49 allelic variants were amplified using the above mentioned primers in which four primer viz. OsZIP7K, OsYSL2K, OsNRAMP7K and OsNACK amplified a single unique allele each and the primer OsZIP5K produced two unique alleles, typically 4.08 alleles per locus, with a range of 1to 6 alleles per primer. The examined rice genotypes are clustered into four broad clusters with a clear differentiation of genotypes into low, moderate and high concentration of grain zinc in them.ThesisItem Open Access Assessing the effect of Heat stress at reproductive stage in Bread wheat (Triticum aestivum L.) genotypes and their molecular characterization(RPCAU, Pusa, 2023) V, ANIRUDH T; SINGH, SATISH KUMARThe current experiment entitled “Assessing the effect of Heat stress at reproductive stage in Bread wheat (Triticum aestivum L.) genotypes and their molecular characterization” was conducted during rabi season 2022-2023. Experiment was undertaken featuring the 30 bread wheat genotypes in Randomised Block Design (RBD) with three replications under timely(normal) and late sown(heat stress) condition was conducted in Research Farm RPCAU Pusa. Data was recorded on the parameters like Plant height, days to heading, days to maturity, grain filling duration, grain filling rate, SPAD, canopy temperature, soil temperature, number of grains per spike, number of effective tillers per plant, thousand grain weight, relative water content, spikelet fertility, pollen fertility, heat susceptibility index. The investigation involved assessing the level of genetic variability, the relationship among the different parameters studied, direct and indirect effects, genetic diversity and molecular diversity with trait specific SSR markers. All the genotypes have shown decreased performance for parameters including spikelet fertility, grain weight, and pollen fertility with the exception of genotypes 41ESYT 102, 9th HPYT 440 for increased Pollen fertility under heat stress condition. Analysis of variance under both timely and late sown environments showed that significant variation exists among the genotypes for all the traits, suggesting that selecting appropriate genotypes based on performance of traits could lead to successful outcomes. Traits with high heritability associated with high Genetic advance as per cent of mean exhibited by number of grains per spike, number of effective tillers per plant, and grain filling rate. Trait grain yield per plant had a substantial positive alliance with Grain filling rate, SPAD, Number of effective tillers per plant, thousand grain weight, Number of grains per spike, Spikelet fertility, Pollen fertility and Relative water content under both conditions. It had a substantial negative alliance with Canopy temperature, Soil temperature, Plant height and Heat susceptibility index. CT revealed negative relation with Grain yield per plant and Grain filling rate indicating that elevated CT leads to yield reduction under heat stressed environment. Attributes like Grain filling rate, SPAD, Number of grains per spike, Number of effective tillers per plant and Relative water content must be prioritised in the selection process for crop improvement as they are positively correlated with grain yield per plant and also has a strong direct effect on grain yield per plant and also the remaining traits contributed indirectly to grain yield. Correlation and direct ,indirect effects implied SPAD, Grain filling rate, Relative water content, Spikelet fertility and Number of effective tillers per plant would be dependable and efficient as they illustrated positively strong association with grain yield per plant and positive interrelation among themselves and also through indirect effects of remaining traits on grain yield per plant. 30 bread wheat genotypes under timely sown environment were clustered into Ⅵ clusters, whereas into Ⅳ clusters under late sown condition. Cluster Ⅲ and Ⅵ reported maximum inter cluster distance followed by cluster Ⅳ and Ⅴ, whereas cluster Ⅲ and Ⅴ reported minimum inter cluster distance under timely sown condition. Under late sown condition , inter cluster distance was recorded maximum and minimum between the cluster Ⅰ and Ⅱ and cluster Ⅱ and Ⅳ respectively Genotype SSN-2021-13 can be selected as suitable donor parent for traits like Grain filling rate, Number of grains per spike, Number of effective tillers per plant, spikelet and pollen fertility and Relative water content under timely sown scenario. Genotype 41 ESWYT-102 can be used in breeding programs for advancement in characters such as number of grains per spike, pollen fertility and Number of effective tillers per plant. Genotype NEST-19-22 will be effective in improvement for SPAD and Grain yield per plant. 26 simple sequence repeat (SSR) markers were used for estimation of molecular diversity in the 30 bread wheat genotypes. These markers produced distinct and scorable bands for the genotypes used. All the 30 genotypes were classified into 5 clusters, Cluster Ⅳ had maximum of 16 genotypes and minimum number of genotypes obtained in Cluster Ⅱ having 2 genotypes. Magnitude of similarity coefficient between 11th HPYT 414 and SSN-2021-13 , followed by11th HPYT 425 and SSN-2021-13, was determined to be maximum. Dissimilarity coefficient was maximum between 11th HPYT 431 and 38 SAWSN 3253, followed by 11th HPYT 431 and 41ESWYT-102.ThesisItem Open Access PHENOTYPING AND DEEPWATER RESPONSE RELATED GENOTYPING OF ADVANCED BREEDING LINES OF RICE(RPCAU, Pusa, 2023) KUMAR, LALAN; Singh, Mithilesh KumarThe current research project, titled “Phenotyping and Deepwater Response Related Genotyping of Advanced Breeding Lines of Rice.” encompassed a collection of 25 genotypes. This study was executed at the RPCAU Research Farm located in Pusa, Bihar utilizing randomized complete block design (RCBD) with two replications during the Kharif season - (2022). The primary objectives of the study were to assess variations in yield and yield components, specifically focusing on grain yield in deepwater conditions. Data were recorded on the parameters like plant height, days to 50% flowering, panicle length, number of tillers per plant, leaf length, number of grains per panicle, kernel breadth, kernel length, test weight, kernel L/B ratio, and grain yield per plant in the field. The investigation involved assessing the level of genetic variability, the relationship among different parameters studied, direct and indirect effects and molecular diversity with respect to trait specific SSR markers. The materials were grown in pots to obtain genomic DNA from young seedlings. The extracted DNA was then subjected to targeted amplification using a set of six SSR primer pairs. The molecular investigations were carried out in the Rice Molecular Breeding Laboratory, situated in the Department of Genetics and Plant Breeding at Pusa. Analysis of Variance revealed that significant differences existed for all the studied traits among the genotypes. PCV was higher than GCV for all the traits, albeit of low difference indicating meagre influence of environment on trait expression. High heritability (h²bs) coupled with high genetic advance was recorded for days to 50% flowering, number of grains per panicle, leaf length, number of tillers per plant, test weight, kernel length, kernel length to breadth ratio and grain yield per plant. Therefore, direct selection for these traits could be rewarding to modify the trait mean in the direction of selection. Correlation and path coefficient analysis revealed that the trait test weight, number of grains per panicle and panicle length had significant positive correlation with grain yield as well as high direct effect on grain yield. Therefore, direct selection for these could be exercised to improve the grain yield. Six simple sequence repeats (SSR) markers were used for estimation of molecular diversity in relation to deepwater response related traits. These markers produced distinct and scorable bands for the genotypes used. All the 25 genotypes were accommodated into 4 clusters, with cluster III having maximum genotypes i.e., 9 and cluster 2 and 4 containing minimum genotypes i.e.,5, each. The markers were polymorphic with PIC value ranging from 0.608 (RM 20562) to 0.825 (RM3769). Genotypes viz. RAU1538-16-5 and RAU1538-16-6 showed minimum genetic divergence with respect to all the SSR markers studied.ThesisItem Open Access CHARACTERIZATION AND STABILITY ANALYSIS OF TRANSPLANTED FINGER MILLET USING MORPHO-PHYSIOLOGICAL TRAITS IN SUMMER(RPCAU, Pusa, 2023) S, ADITHYA RAJENDRAN; MISHRA,SWETAThe present study was conducted to determine the effect of genotype, environment and their interaction for grain yield and to identify more stable finger millet genotypes for summer season. The experiment was laid down in Augmented block Design and 144 finer millet genotypes along with 3 checks (RAU-8, GPU-67 and VL-376) were evaluated for 2 summer seasons of 2022 (season 1) and 2023 (season 2). There were highly significant variations among genotypes for all the quantitative traits studied. The mean grain yield averaged over seasons ranged from 309.74 kg/ha to 3012.35 kg/ha in season 1 and from 429.13 kg/ha to 2931.64 kg/ha in season 2. Days to 50% flowering, days to maturity, finger length, finger width, ear length, fingers per ear, plant height, number of basal tillers, productive tillers per plant, 1000 grain weight, flag leaf blade length, flag leaf blade width and peduncle length showed significant positive correlation with grain yield in season 1 and season 2. finger length, fingers per ear, number of basal tillers, 1000 grain weight, flag leaf blade width and peduncle length showed positive direct effects with grain yield in season1 and season 2. For qualitative morphological traits most genotypes showed erect type of plant growth habit, compact ear shape, absence of finger multiple whorls, absence of finger branching, copper brown seed colour, round shaped seeds, absence of stem culm branching, dark green coloured glume, absence of seed shattering and persistent pericarp. Some genotypes showed finger branching in thumb finger. Among the genotypes, RAU-FM-Sheohar-2009-19 (987.0) and RAU-FM-Sheohar-2009-9 (964.9) showed higher values for seed vigour index I. RAU-FM-83 (1.271), RAU-FM-Gopalganj-2009-5 (1.144) and RAU-FM-93 (0.960) showed higher values for seed vigour index II. RAU-FM-Sheohar-2009-9 (11.38cm) outperformed the check varieties in terms of seedling length. Most of the genotypes showed 100% seed germination. RAU-FM-Sheohar-2010-9 recorded higher value (18.4) for chlorophyll content. RAU-FM-82 exhibited a comparable performance with check varieties for speed of germination with a value of 3.33. RAU-FM-Sheohar-2009-9 which showed a better performance for seed vigour index I, seedling length and chlorophyll content, had high flag leaf blade length. Genotypes RAU-FM-83 and RAU-FM-Gopalganj-2009-5 which had high vigour index II also had higher values for days to 50% flowering. RAU-FM-Sheohar-2009-14 which had high seedling length and RAU-FM-82 which had high speed of germination showed higher mean performance for plant height. RAU-FM-100 also had high speed of germination as well as showed a better mean performance for days to 50% flowering and days to maturity. GGE Biplot showed that RAU-FM-Kanti-2010-1 showed stable performance for ear length; RAU-FM-Sheohar-2009-14 for fingers per ear; RAU-FM-114 for productive tillers per plant and RAU-FM-86 for 1000-grain weight, respectively. RAU-FM-86 showed better mean performance for the trait fingers per ear. As per GGE Biplot analysis, the summer season was new in Bihar where finger millet is being introduced for the first time. So, this maybe the reason that the biplot didn’t include the seasons under ideal environment. The genotypes RAU-8, GPU-67 and VL-376 were identified for stable performance in terms of yield. Though these are released varieties, they are usually grown in kharif season and were new to summer season and hence can be either evaluated for more summer seasons. The genotypes showed better performance of other traits can be selected for more summer seasons or used as a donor parent for the particular traits in pre-breeding programmes in future.ThesisItem Open Access STABILITY ANALYSIS OF RICE GENOTYPES UNDER BORO CONDITION(Dr.RPCAU, Pusa, 2023) CHHAYA, RUCHIKA; NILANJAYAThe present experiment was carried out at Pusa Rice farm of Dr. RPCAU, Pusa, Bihar during Boro season of 2021-22 and 2022-23 using 30 rice genotypes in Randomized Block Design with two replications and two dates of sowing under four environments. E1 (10th Dec 2021 sowing and transplanting on 05th Feb 2022), E2 (25th Dec 2021 sowing and transplanting on 20th Feb 2022), E3 (10th Dec 2022 sowing and transplanting on 05th Feb 2023) and E4 (25th Dec 2023 sowing and transplanting on 20th Feb 2023) were the combinations of environments. In ANOVA for all the traits, highly significant variation was obtained due to genotypes sources of variation across four environments. The pooled analysis of variance was also observed to be highly significant for all sources of variation for all the traits. By going through mean performance results we could summarize that E3 and E4 environments were found as better for majority of traits studied compared to other environments. G7, G15, G12 and G22 were good performer for almost all the traits in more than one environment (E1, E3 and E4). It became evident by analysis of sixteen traits across four environments that genotypes which performed better as compared to Gautam € were supposed to be promising one for cold tolerance. These are as follows: G21 was found superior for Length of root at seedling stage, Sterility percentage, Test weight, SPAD value, Proline content and Grain yield (g/plant) whereas G27 and G6 were stable genotypes for Length of shoot at seedling stage, Shoot/root ratio, Filled grains, Days to 50% flowering, Days to maturity, Spikelets per panicle and Relative water content. The ANOVA for stability analysis was highly significant for genotypes (G) for all the traits. Environments €, [E+ (GxE)] and non- linear components were highly significant for majority of traits. On consideration of different stability parameters G27, G21 and G14 seemed to record predictable performance with non-significant S2 di and greater (bi>1) value for majority of traits i.e genotypes were responsive and could be recommended for specific or favourable environments whereas G16, G25 and G7 showed predictable performance with non- significant S2 di and less (bi<1) value for most of the traits i.e it can be suitable for poor or unfavourable environmental conditions. GGE biplot graphical representation inferred that single mega environment existed for Sterility percentage, Filled grains, Plant height (cm), Length of root at seedling stage and Grain yield whereas two mega environments present in case of Length of shoot at seedling stage, Shoot/root ratio, Germination percentage, Sterility percentage, Test weight, Proline content, and Relative water content. However, three mega environments were seen in case of Unfilled grains and SPAD Value. From GGE biplot G and E view suggested that G12, G27 and G22 were ideal genotypes. E1, E2 and E3 environments were most discriminating for selecting rice genotype adapted for the region. These stable genotypes could be utilised in future as parents for crop improvement program for developing cold tolerant rice genotypes at seedling stage and heat tolerant at flowering stageThesisItem Open Access COMPARATIVE DIVERGENCE STUDIES IN BREAD WHEAT (Triticum aestivum L.) UNDER TIMELY AND LATE SOWN CONDITION FOR ZINC BIOFORTIFICATION(Dr.RPCAU, Pusa, 2020) KUMARI, SHARDA; Singh, Satish KumarA study was conducted at Wheat Breeding section, RPCAU, Pusa, Samastipur, Bihar during Rabi 2017-18 to evaluate the genotypes of bread wheat (Triticum aestivum L.) under timely and late sown conditions. Observation were recorded on plant height, number of tillers per plant, flag leaf area, days to fifty per cent flowering, canopy temperature, relative water content, spike length, number of grains per spike, spike fertility, chlorophyll content, days to maturity, thousand grain weight, harvest index, yield per plant, zinc content and heat susceptibility index. 28 genotypes were grown under two environments namely non stressed (timely sown) and stressed (late sown). The experiment in each environment was laid out in Randomized Block Design with three replications. Analysis of variance revealed highly significant differences among the accessions for all the parameters except canopy temperature under both timely and late sown conditions. The phenotypic and genotypic coefficient of variance was found to be low for days to fifty per cent flowering, harvest index, spike fertility, grains per spike under both the environment (late and timely). Heat susceptibility index showed highest GCV and PCV under late sown condition. It is interesting to note that the differences between GCV and PCV values were minimum implying least influence of environment. Heritability in broad sense for all the characters namely days to fifty per cent flowering, thousand grain weight were found to be high in both environments. The four characters namely heat susceptibility index, number of tillers per plant, flag leaf area, chlorophyll content were found to have high heritability under late sown condition. The characters, namely days to fifty per cent flowering exhibited high heritability coupled with medium genetic advance as per cent of mean under both environments. Hence, direct selection can be done through this character for future improvement of genotypes. The four characters namely heat susceptibility index, number of tillers per plant, flag leaf area, thousand grain weight, chlorophyll content were found to have high heritability revealed high heritability with moderate genetic advance as per cent of mean under late sown condition, whereas days to maturity showed high heritability with low genetic advance as per cent of mean in timely sown condition. Moderate heritability coupled with low genetic advance as per cent of mean were observed for traits like number of grains per spike in both environments. Spike length, flag leaf area exhibited moderate heritability with low genetic advance under timely sown condition . Relative water content, plant height, spike fertility, shows medium heritability with low genetic advance under late sown condition. Zinc content showed medium heritability with medium genetic advance under late sown condition. All genotypes showed higher yield under timely sown condition compared to late sown condition, indicating the potential of genotypes to yield better if the favourable condition prevailed. 28 genotypes were grouped into five clusters under timely sown condition but distribution of genotypes in cluster was dissimilar. Under timely sown condition, the maximum intra cluster distance was recorded in cluster III followed by cluster II and I. The least intra cluster distance was observed in cluster IV and V indicating close resemblance between the genotypes presented in these cluster. The maximum inter cluster distance was observed between cluster III and V followed by cluster I and III, cluster II and IV, cluster III and IV and cluster I and II indicating the chances of getting high yielding recombinants would be better if the crosses are made among the genotypes of these groups. The lowest inter cluster distance was recorded between cluster I and IV followed by cluster I and V, cluster II and IV showing these clusters were relatively less divergent. The maximum contribution in the manifestation of genetic divergence in timely sown condition was exhibited by days to fifty per cent flowering, followed by thousand grain weight, number of grains per spike, grain yield, number of tillers per plant, spike length, zinc content under late sown condition suggesting scope for improvement in these characters. In other words, selection for these characters may be rewarding. In late sown condition, in the present investigation, 28 genotypes (including check) were grouped into nine clusters on the basis of D2 statistics and ward minimum variance. Cluster II comprises highest number of genotypes (17) followed by cluster I (4). Whereas, the cluster III, IV, V, VI, VII, VIII, and IX were solitary (monogenotypic), comprising single genotype each. Cluster III may be selected as a donor for dwarfness. For the purpose of earliness, cluster VIII followed by I, V were most suited. The genotypes in cluster (IV and VIII) followed by cluster (VII and VIII), due to maximum inter cluster distance between them, exhibited high degree of genetic diversity and thus may be utilized under inter varietal hybridization programme (transgressive breeding) for getting high yielding recombinants. The highest contribution in the manifestation of genetic divergence in late sown condition was depicted by days to fifty percent flowering followed by heat susceptibility index, thousand grain weight and zinc content. This indicated that selection of genotypes for these traits may be rewarding for future utilization in breeding programme.ThesisItem Open Access VALIDATION OF SSR MARKERS ASSOCIATED WITH RESISTANCE TO BROWN SPOT DISEASE IN RICE(Dr.RPCAU, Pusa, 2021) BANSHIDHAR; KUMAR, RAJESHRice is cultivated in a wide range of agro-climatic and agro-ecological areas under dry to semi dry conditions and/or wet conditions. On account of its extensive cultivation it is adversely affected by a number of insect-pest and diseases. Among, these brown spot of rice caused by Cochliobolus miyabeanus is a disease of economic significance in the locale of study since it is the hotspot for the disease.The pathogen infects the crop on almost all above ground parts, from nursury to maturity stages and form small dark brown to purplish-brown spots on leaves that later enlarge into oval lesions with brown necrotic centers that are frequently surrounded by chlorotic halo. These spots appear even on seeds resulting in significant economic losses both in grain quality and yield. An immediate and judicious solution to these problem lies in breeding of high yielding resistant cultivars that could be strategically employed for disease management. Keeping this in view the present investigation entitled “Validation of SSR markers associated with resistance to brown spot disease in rice’’ was undertaken to phenotypically screen 300 genotypes of rice along with three checks for two consecutive season in Kharif 2019 and 2020 in controlled condition (glasshouse of department of Plant Pathology) as well as in field (Rice research farm, RPCAU, Pusa, Samastipur, Bihar) to identify resistant sources that could be either utilised directly as a resistant variety or as a parent in hybridisation programme to develop resistant varieties. These genotypes were also evaluated for eight morphological traits related with yield in Kharif 2019 and 2020 in field in augmented design to detect an association between disease resistance and morphological traits under study. Further, 15 most resistant and 15 most susceptible genotypes selected on the basis of AUDPC values were subjected to molecular characteristaion to support the phenotypic screening through genotypic evaluation using 18 SSR markers linked with brown spot disease in rice. The findings of molecular characterization were analysed for validation of these SSR markers in the selected population and to identify a significant marker trait association for the validated linked SSR markers. On the basis of phenotypic screening 18 genotypes were categorised as resistant, 90 genotypes were categorised as moderately resistant, 149 genotypes were categorised as moderately susceptible and 46 genotypes were categorised as susceptible. The mean values for various disease estimating parameters and morphological traits were utilized in various statistical analysis to derive all other complex statistics viz. standard deviation, coefficient of variation, genetic advance as percentage of mean, etc. The analysis of variance revealed significant differences among all genotypes for all the traits. This indicates that there is ample scope for selection of promising lines from the present gene pool for yield and disease resistance. The phenotypic coefficient of variation was slightly greater than the genotypic coefficient of variation (GCV) for all traits under study which reveals lower influence of environment on inherent potential of a trait and higher genetic inherent potential which is a prerequisite in any crop improvement programme. High estimates of heritability in broad sense and genetic advance as percent of mean was observed for each trait under study which inferred that selection for these traits promises improvement in desired direction of selection. From the association studies, it was observed that days to 50% flowering, days to physiological maturity and plant height had positive correlation with AUDPC while negative correlation with yield per plant. In contrary to this, panicle length, number of effective tillers per plant, number of grains per panicle and test weight had negative correlation with AUDPC while positive correlation with yield per plant. Number of grains per panicle, number of effective tillers per plant and test weight showed high direct positive effect on grain yield while days to physiological maturity showed the high direct negative effect on yield. Molecular characterization of selected genotypes showed that the amplified product of resistant genotypes with most of the primer pair were in accordance to the expected band size for a primer pair as per Gramene data base for SSR markers. Total of 6 primer pairs out of 18 primer pairs included in the study were validated and showed moderate to highly significant marker trait association. Thus, these markers could be used to differentiate the resistant lines from the susceptible one and could be used for marker assisted selection of brown spot resistance lines. The conclusive findings of present investigation pave the way for high ends breeding programmes aimed at long lasting field resistance against brown spot pathogen. The genotypes which were reported to be resistant can be used as donor in various resistance breeding programmes. Findings from the molecular characterisation and validation of primer pairs will precisely guide the further research activities in selection of markers for brown spot resistance genotyping. In a nutshell, the reported findings from present investigation will be quite helpful for students, breeders, farmers and others who are in academic and research activities as a good source of information in selecting improved genotypes for various breeding programmes.ThesisItem Open Access CANDIDATE GENE BASED MICROSATELLITE PROFILING IN RELATION TO FRAGRANCE OF LAND RACES AND IMPROVED VARIETIES OF AROMATIC RICE(Dr.RPCAU, Pusa, 2021) Kumar, Abhay; SHARMA, V.K.A study was performed to evaluate the genetic polymorphism using candidate gene based microsatellite specific reported and designed primers and to validate them in relation to fragrance in 18 rice genotypes. Molecular-level genetic divergence along with the importance of candidate genes based microsatellite markers was assessed in relation to fragrance in these landraces and improved varieties of aromatic rice used as experimental material during molecular profiling. The experimental materials were grown in aluminum containers to extract genomic DNA from young seedlings. The targeted amplification of genomic DNA was achieved using candidate genes based microsatellite specific 24 reported primer pairs and candidate genes based microsatellite specific 38 designed primer pairs. Based on the information available in the literature, a total of eleven genes, namely, Os03g0327600, Os04g0352400, Os04g0434800, Os04g0401700, Os04g0438300, Os04g0445700, Os04g0468600, Os04g0474800, Os04g046970, Os08g0424500 and OsNPB_0504555500, which are known to be associated with aroma in aromatic rice, were searched through the internet. The fragrance related these 11 candidate genes are located on the short arm of four different chromosomes (3, 4, 8 and 5) existing in the rice genome. A total of 47 SSR sequences were detected for all eleven candidate genes by using BatchPrimer3 v1.0 software under investigation. Most of the SSRs were tri-nucleotides followed by di-nucleotides; only few were tetra- nucleotides. As a result, altogether investigated 38 microsatellites contained 10, 22, and 06 microsatellites with di-nucleotide, tri-nucleotide and tetra-nucleotide repeat motifs, respectively. The gene Os08g0424500 possessed the highest number of SSRs, while gene Os04g0445700 and Os04g0474800 were not observed to possess any SSR. Differential amplification profile was ascertained amongst the genotypes subjected to molecular characterization by employing 24 reported and 38 designed microsatellite specific primer pairs. The migration of amplicons resulted in appearance of bands representing amplification products localized at different positions on the gel, reflecting the variation in product length derived by primer directed amplification of genomic templates. By using 24 reported primers, a survey of the molecular profiles generated on the basis of the evaluation of the amplified products clearly indicated that a total of 160 alleles were detected with an average number of 6.66 alleles per primer. Similarly, by using 38 designed primers, a total of 248 allelic variants were detected with an average number of 6.52 alleles per primer. Null allele was also noticed in the specific combinations between genotypes and primers. Statistical measure of polymorphic information content (PIC) of the 24 reported microsatellite primer pairs, which reflected allelic diversity and frequency among the genotypes, varied from 0.638 to 0.870. Similarly, for the 38 designed primers, polymorphic information content (PIC) varied from 0.692 to 0.880. Polymorphism per cent generated by these 24 reported primer pairs varied from 0.00 to 62.50 with an average of 24.26 per primer. Similarly, by using 38 designed primers, polymorphism per cent varied from the 0.00 to 66.66. The reported primers CHR 8_34, CHR 3_20, CHR 3_24, CHR 4_3, CHR 8_10, CHR 3_10 and CHR 8_5 appeared to be highly informative primers with above average polymorphism per cent and polymorphic information content. Similarly, the designed primers, CHR4.1_1, CHR4.1_5, CHR4.1_6, CHR4.1_10, CHR4.1_11, CHR4.1_13, CHR8.1_4, CHR8.1_6, CHR8.1_9, CHR8.1_10, CHR8.1_11, CHR8.1_12, and CHR8.1_21 appeared to be highly informative primers with above average polymorphism per cent and polymorphic information content. The results indicated a relatively higher magnitude of discrimination coefficient for the reported primer pairs CHR3_16, CHR3_10, CHR3_20, CHR3_24, CHR4_3, CHR4_25, CHR4_26, CHR8_29, CHR8_6, CHR8_49, CHR8_10, and CHR8_5. Similarly, for the designed primers the relatively higher magnitude was found for the primers CHR3.1_2, CHR4.1_1, CHR4.1_5, CHR4.1_6, CHR4.1_8, CHR4.1_10, CHR4.1_11, CHR4.1_12, CHR4.1_13, CHR8.1_4, CHR8.1_7, CHR8.1_9, CHR8.1_10, CHR8.1_11, CHR8.1_13, CHR8.1_15, CHR8.1_17, CHR8.1_20, CHR8.1_21, and CHR8.1_22. Differential amplification pattern revealing molecular level genetic polymorphism among the genotypes subjected to molecular characterization provided a basis for deducting that the sequence length variation observed in candidate genes may be a role player in differential fragrance in landraces and improved varieties of aromatic rice. Sizable variation was clearly recognized in the molecular size of the genomic region targeted by the primer pairs. The values of similarity coefficient ranged from 0.00 to 0.641, 0.024 to 0.481 and 0.015 to 0.545 for pair-wise combinations of genotypes by using 24 reported primers, 38 designed primers and 62 combined (reported and designed) primers based binary matrices data. Wide genetic differentiation and divergence at the molecular level was revealed among the genotypes. Hierarchical pattern of classification based on similarity coefficient matrix of pair-wise combinations of genotypes was in extremely good agreement with principal coordinated analysis based spatial distribution pattern of genetic profiles of genotypes. Hierarchical cluster analysis, as well as principal coordinate analysis using microsatellite-specific markers derived from candidate genes made it possible to differentiate aromatic landraces and improved varieties of rice. The landraces were discriminated from improved aromatic varieties and accommodated into different cluster. The computational analysis of the genetic structure of the aromatic landraces and improved varieties unambiguously reflected that the genotypes subjected to fragrance related molecular characterization are the admixture of three ancestral components present in different combinations in different genotypes. The Practical utility of the fragrance related candidate gene specific designed primers in discrimination of aromatic landraces and improved varieties was amply demonstrated. The results led to validation of designed primers by amply demonstrating their efficiency to discriminate aromatic landraces from improved varieties of aromatic rice. These reported and designed candidate genes based SSR primers could be utilized for molecular characterization, identification, genetic divergence analysis, parental selection and biological individuation in relation to fragrance of landraces and improved varieties of aromatic rice.
