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Open Access
Effect of nitrate and ammonium ratios on physiological and quality attributes of hydroponically grown leafy vegetables
(Punjab Agricultural University, Ludhiana, 2019) Ratnesh Kumari; Bedi, Seema
The effect of variable NO3 -to NH4 + ratios in the nutrient solution was evaluated on growth, nutritional quality and yield attributes of hydroponically grown leafy vegetables. Spinach (cv. Punjab Green), Coriander (cv. Punjab Sugandh) and Lettuce (cv. Iceberg) grown under substrate hydroponics with intermittent supply of water and nutrients. Simultaneously crop was raised in open field by conventional practices. Crop was sown on three dates viz., October (main season) and February and July (off-season) respectively. N was supplied in variable ratios of NO3 - to NH4 + viz., 100:0 (T1), 75:25 (T2), 50:50 (T3), 25:75 (T4), 0:100 (T5) respectively, keeping total N content constant. Fresh foliage was harvested 3 times in each season from each respective treatment at 30 days interval starting from date of sowing. At each harvesting, growth (fresh and dry biomass of shoot and root, plant height, leaf area and total yield per plant), quality parameters (total chlorophyll, carotenoids, soluble sugars, starch, soluble proteins, free amino acids and proline) and antioxidant enzyme activities (SOD, CAT, and POD) were determined. During all the three seasons, the yield was significantly more in hydroponically than open field sown crop. Under substrate hydroponics, maximum yield was obtained in the plants provided with nutrient solution T2 (NO3 - : NH4 +:: 75:25) and also had higher values of quality parameters and highest antioxidants activities than the open field crop. It is suggested that NO3 - to NH4 + ratio of 75:25 improve the growth, antioxidants activity, quality attributes and is thus most suitable for leafy vegetables growth under substrate hydroponics.
Open Access
Morpho-physiological and biochemical characterization of a recombinant inbred line population of rice (Oryza sativa L.) under direct-seeded aerobic conditions
(Punjab Agricultural University, Ludhiana, 2014) Cheema, Amandeep Kaur; Bedi, Seema
Direct seeding of rice (Oryza sativa L.) is a resource conservation technology but at the cost of reduction in yield. In the present study, recombinant inbred lines (RILs) obtained from a cross between PR 120 x UPLRi 7 were sown as direct-seeded aerobic and conventional transplanted crops respectively for two seasons. Various morpho-physiological, biochemical and yield related traits were studied under the two conditions. In general, plant height, dry matter, crop growth rate, relative growth rate, leaf area and chlorophyll content were lower under direct-seeded aerobic conditions than under conventional transplanted conditions. Plant height and crop growth rate showed a positive correlation with grain yield and had a direct effect on grain yield. Dry matter accumulation did not show any significant correlation but had an indirect effect on grain yield. Relative growth rate, leaf area and chlorophyll content did not show any correlation or effect on grain yield. All the yield contributing traits viz., above ground biomass, total number of tillers per 0.5m row, number of fertile tillers per panicle per 0.5m row, spikelets per panicle, grain filling percentage, grain yield per 0.5m row, harvest index, 1000 grain weight were lower and sterile grain per panicle were higher in direct-seeded aerobic condition. Above ground biomass and harvest index showed correlation with yield and had a direct effect on grain yield under both direct-seeded aerobic and conventional transplanted conditions. In general, higher sugar, starch and proline content were detected in leaves of direct-seeded aerobic crop. Out of twenty RILs under study, Ae-RIL-B-158, showed highest proline and sugar contents. Interestingly, this RIL showed least reduction in yield when sown under direct seeded-aerobic condition as against conventional transplanted condition suggesting this RIL may be more tolerant to drought stress as it accumulated highest proline and sugars under direct-seeded aerobic condition. The development of aerenchyma was comparatively more in crop raised under conventional transplanted conditions than under direct-seeded aerobic conditions. UPLRi7 (parent) showed maximum aerenchyma under direct-seeded aerobic conditions while PR120 (parent) showed maximum aerenchyma formation under conventional transplanted conditions. Under both the sowing conditions, two high-yielding RILs (Ae-RIL-B-42 and Ae-RIL-B-44) had higher aerenchyma than the two low-yielding RILs (Ae-RIL-B-7 and Ae-RIL-B-117). These characters could be used as criteria for selecting RILs for incorporating into breeding programmes for yield enhancement.
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Comparative study of floral biology, fruit growth and associated metabolic changes in mandarin (Citrus reticulata Blanco.) genotypes
(Punjab Agricultural University, Ludhiana, 2019) Shabnam; Nirmaljit Kaur
The present investigation entitled, “Comparative study of floral biology, fruit growth and associated metabolic changes in mandarin (Citrus reticulata Blanco.) genotypes” was carried out during 2017 and 2018. Fifteen mandarin genotypes, viz., Clone 11, CRS 4, N 4, N 28, N 34, Nagpur mandarin, Nagpur seedless, W.Murcott, Kinnow, Daisy, PAU Mutant 1, Mutant 2, Mutant 3, Mutant 4 and Mutant 5 at PAU, Ludhiana and three mandarin genotypes, viz., W.Murcott, Kinnow and Daisy at Dr. J C Bakshi RRS, Abohar were selected for their physical, morphological, anatomical and biochemical characterization. Results revealed the existence of wide variation among mandarin genotypes and years of investigation. The quanlitative and quantitative characters of flowers, leaves and fruits differed significantly among genotypes and the locations. These variations were indicative of the underlying genetic diversity and the influence of environmental factors. Anatomical studies revealed that the area under xylem tissues decreased in the pedicel of dropped fruits. Clone 11 and Kinnow prove promising in terms of yield data at harvest. This study provides supporting evidence on the basis of biochemical attributes for the superiority of PAU Mutant 1 fruit, released by Punjab Agricultural University, as an excellent source of major value added nutritional bioactive compounds. Results on endogenous IAA contents of ovaries correlated positively to fruit growth and development. Observations on organic acids profile of mandarin genotypes revealed that citric acid is the major organic acid, followed by ascorbic acid. N 34 genotype of mandarin might be used for high oil productivity. A comparative study was done with the mean of two years data in three mandarin genotypes (W.Murcott, Kinnow and Daisy) to investigate variation in qualitative and quantitative characters of three genotypes at two different locations. However, among mandarins grown at PAU, Ludhiana and Dr. J C Bakshi RRS, Abohar, a single variety does not emerge as the best on the basis of their collective physical, morphological, anatomical and biochemical characterization. This study of mandarin genotypes characterization may be useful for the selection of a genotype for desired quality characteristics as per specific market demand.
Open Access
Germination ecology of Medicago denticulata Willd. in relation to seed coat colour, persistence and herbicide exposure
(Punjab Agricultural University, Ludhiana, 2019) Sethi, Renu; Navjyot Kaur
The present study entitled, “Germination ecology of Medicago denticulata Willd. in relation to seed coat colour, persistence and herbicide exposure" was conducted at Punjab Agricultural University, Ludhiana and Dr. J.C. Bakhshi Regional Research Station, Abohar. Under natural conditions, M. denticulata produces heteromorphic seeds differing in seed coat colour - cream and brownish black. The study was aimed to compare the effect of seed coat colour on dormancy and germination behaviour of M. denticulata seeds and response of heteromorphic seeds to various environmental variables and herbicide exposure. Brownish black seeds were non-dormant with high moisture content. Cream seeds with low moisture content were dormant and germinated only when subjected to dormancy breaking treatments indicating seed coat imposed dormancy. Germination of both cream and brownish black seeds was independent of light. Cream seeds germinated in the wide temperature range of 15/5 to 30/20°C; while brownish black seeds germinated in narrow temperature range of 15/5 to 25/15°C. Brownish black seeds recorded no germination at 200 mM NaCl; whereas, some cream seeds (10%) were able to germinate at this NaCl concentration. The osmotic potential required for 50% inhibition of maximum germination of cream and brownish black seeds was -0.37 and -0.32 MPa, respectively. Brownish black seeds accelerated aged for 20 recorded no germination. Whereas, some cream seeds (∼13%) aged for 20 days were still able to germinate. Cream seeds placed on soil surface or buried at 2 and 10 cm depth germinated up to 12 months; but no germination was observed in brownish black seeds buried for 12 or more months. Therefore, cream seeds may have longer persistence than brownish black seeds. Herbicide sprays at eight and twelve-leaf stages of M. denticulata reduced seed production potential of this weed with concomitant decrease in germination as compared to herbicide sprays done at four-leaf stage of M. denticulata. This indicated possibility of herbicide carry-over effect from parent plants.
Open Access
Physiological, biochemical and molecular parameters for assessing viability and vigour of hot pepper (Capsicum annuum L.) seeds during storage
(Punjab Agricultural University, Ludhiana, 2019) Hagroo, Ruzeena Parvaiz; Bedi, Seema
The present study was conducted on hot pepper (capsicum annuum L.) cultivar Punjab Sindhuri and hybrid CH-27 seeds. Hot pepper is an important spice crop of India and the quality of its seed is an important commercial trait. However, the seeds undergo loss of quality when stored for intervening months between harvesting and next sowing. To establish the physiological, biochemical and molecular aspects of seed ageing, freshly harvested seeds of hot pepper var. Punjab Sindhuri and hybrid CH-27 were stored in refrigerator (controlled ageing) and at room temperature (natural ageing) for 12 months. The seeds kept for controlled ageing were drawn at 3 monthly intervals and subjected to accelerated ageing for 3, 6, 9 and 12 days respectively. Ageing significantly affected seed quality in terms of physiological (germination per cent, mean days to germination, seedling vigour index, seedling length, seedling fresh and dry weight, electrolytic leakage and moisture content), biochemical (content of total soluble sugars, starch, total soluble proteins, total free amino acids, ascorbic acid, α-tocopherol, malondialdehyde, hydrogen peroxide, change in protein profile by SDS PAGE, activity of enzymes, viz; POD, SOD, CAT, α-amylase activity and molecular (alteration in DNA by SSR markers) aspects. To restore the germinability after storage period the seeds were primed in KNO3, GA3, PEG and Ascorbic acid. All priming treatments significantly improved germination parameters over control but the treatments differed among themselves in magnitude. The improvement in seed quality and germination parameters due to priming was attributed to increased activity of antioxidant enzymes (POD, SOD, CAT) and reappearance of some protein bands degraded during storage.
Open Access
Morpho-physiological characterization of Mexican wheat landraces for traits of Economic importance
(Punjab Agricultural University, Ludhiana, 2018) Ankita; Sarlach, R.S.
The present research work on “Morpho-physiological characterization of Mexican wheat landraces for traits of Economic importance” was carried out to explore the genetic diversity of landraces for drought and salinity stress tolerance. The study was carried out at wheat laboratory and experimental area of Department of Plant Breeding & Genetics, Punjab Agricultural University, Ludhiana during 2015-16 and 2016-17. A set of 1161 Mexican wheat landraces was procured from CIMMYT, Mexico and was sown in field in augmented block design. The landraces set was narrowed down to a smaller set on the basis of their yield potential and seed availability. Selected 177 Mexican wheat landraces were subjected to salinity and drought stress conditions. To find the salinity stress tolerance among Mexican wheat landraces, they were subjected to different concentration of sodium chloride (0, 25mM, 50mM, 75mM, 100mM, 125mM and 150mM) in laboratory. Among different concentration of NaCl, 125mM was found to be the optimum dose for screening. Similarly, to find the drought stress tolerance among Mexican wheat landraces, these were subjected to different concentration of PEG (6000) 0 (control), 2%, 4% 6% 8%,10%,12%,14%,16% and 18%.Dose of 14% was found to be the optimum dose for further screening. The landraces selected from the laboratory screening at seedling level were further evaluated for drought stress (irrigated, restricted irrigated and rainfed conditions) and salinity stress tolerance (Rajpura and Rattakhera, Sri Muktsar Sahib) under actual field conditions and in pots with simulated salinity stress conditions (control, 120mM and 240mM NaCl).The soil of Sri Muktsar Sahib was slightly alkaline having pH 8.1 and high EC (0.948 dS/m). The district contains high salinity and water logged area. And the soil of Rajpura was alkaline having pH 8.5 and high EC (1.97 dS/m). The landraces MICH89.4.28, MICH89.5.5, VERY LATE, HGO94.10.7, MEX94.19.52 performed well under actual field and simulated salinity stress conditions. The drought stress was created by withholding of irrigations (rainfed conditions) pre-irrigation before sowing and subjected to rainfall for water requirements, irrigated conditions (regular recommended irrigation) and restricted (1-2 irrigation after sowing). The morpho-physiological data was recorded. The landraces TXL92.1.1.58, PBL94.14.17, HGO94.5.124, HGO94.5.130, HGO94.9.2.29 and HGO94.8.113 performed well under drought stress conditions. These landraces can be used for introgressing the salt and drought tolerance traits into commercial wheat cultivars for development of tolerant wheat varieties.
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Partitioning of zinc and its associated metabolites in diverse rice (Oryza sativa L.) genotypes
(Punjab Agricultural University, Ludhiana, 2018) Avneet Kaur; Nirmaljit Kaur
The present investigation entitled “Partitioning of zinc and its associated metabolites in diverse rice (Oryza sativa L.) genotypes” was undertaken in the Department of Botany, Punjab Agricultural University, Ludhiana during 2016-17. Seeds of sixteen genotypes with diverse zinc content were procured from the Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana. The studies were conducted in two experiments, in the first experiment sixteen rice genotypes were raised in the nursery and; physiological and biochemical parameters of rice genotypes were quantified from 35-days old seedlings. The chlorophyll pigments, hill activity, total soluble sugars, total soluble proteins, free amino acids, starch and superoxide dismutase (SOD) activity were recorded higher in PR113 and PR121, whereas these were lower in RYT Biofort1 and RYT 3403 as compared to the rest of the genotypes. Grain weight, grain yield and grain zinc uptake also followed similar trend. Hence, PR113 and PR121 were characterized as zinc efficient, whereas, RYT Biofort1 and RYT 3403 as zinc inefficient. These zinc efficient and zinc inefficient genotypes were put to further experimentation. The zinc content and zinc associated traits were quantified during three stages of development: maximum tillering, anthesis (50% flowering) and maturity. The chlorophyll content, hill activity and SOD activity increased significantly from maximum tillering to anthesis stage and these parameters were also higher in zinc efficient genotypes as compared to zinc inefficient genotypes. The total soluble sugars, total soluble proteins, free amino acids and starch increased significantly from maximum tillering to anthesis stage, whereas decreased from anthesis to maturity. These metabolic reserves were higher in zinc efficient genotypes as compared to the zinc inefficient genotypes. The plant height, leaf area, flag leaf area, leaf weight, number of tillers and internodal length was also higher in zinc efficient genotypes as compared to the zinc inefficient genotypes. The leaf, tiller, spike and grain were separated at each representative stage of growth for quantifying weight, zinc content and zinc uptake. A higher dry matter accumulation as well as zinc remobilization from the vegetative to reproductive parts of the plant was observed in the zinc efficient genotypes as compared to the inefficient ones.Panicle characteristics, viz., panicle length, panicle number per m2, filled spikelet percentage and percent grain filling were high in zinc efficient genotypes, whereas low in zinc inefficient genotypes. On the contrary, panicle sterility was high in the zinc inefficient genotypes. Yield and yield contributing traits, viz., test weight, grain weight per plant, grain yield and harvest index were high in the zinc efficient genotypes as compared to the zinc inefficient genotypes. Based on the present investigation, PR113 and PR121 have been characterized as zinc efficient and RYT Biofort1 and RYT 3403 as zinc inefficient genotypes.
Open Access
Morphophysiological basis of manganese deficiency tolerance in progenies derived from wheat  triticale crosses
(Punjab Agricultural University, Ludhiana, 2018) Ramanjit Kaur; Sarlach, R.S.
Manganese (Mn) is one of the leading micronutrient deficiency disorders in alkaline and calcareous soil of Punjab due to wheat-rice crop rotation system. Mn efficiency is an ability of a plant to have greater Mn uptake in the Mn deficient soil too. This study was designed to refine the half seed technique for screening of efficient progenies derived from wheat x triticale crosses at seedling stage on the basis of specific visual symptoms of Mn deficiency in the pot experiment and then validated in the Mn deficient field. Taking in account its traits to be introgressed from rye and the preliminary indications of micronutrient deficiency tolerance, the proposed study has been devised to explore the potential of Mn deficiency tolerance in the germplasm. In the first pot experiment, nine wheat genotypes were sown using half and full seed under Mn deficient conditions. Being most sensitive to Mn deficiency durum wheat cultivar PDW 233 showed earliest symptoms in half seed rather than full seed. It helped to validate the method of screening. This novel method of screening was used to evaluate lines derived wheat x triticale crosses. Durum wheat, bread wheat and triticale were used as standard sensitive, moderate and tolerant control respectively. Out of seventy two lines, only forty two were selected on the basis morpho-physiological traits like root-shoot length (cm), dry matter accumulation (g), days to germination (DTG), vigour index, relative growth rate, days to deficiency symptom appearance, yield contributing traits, Mn indices and stress tolerance index. Biochemical analysis of selected lines was carried out later in laboratory. Lines derived from first cross TL2908/2*CS(S)//PBW343 were 3-TL to 5-TL, 8-YRR-TL, 12-TL, 14-TL, 15-YRR-TL, 21-TL to 26-TL, second cross T3048/2*CS(S)//PBW343 were 28-T3048 to 38-T3048, 43-T3048, 46-T3048 to 48-T3048, 51-T3048, third cross 54-T3065/2*CS(S)//PBW343, forth cross 56-T3048/2*CS(S)//DBW17 to 59- T3048/2*CS(S)// DBW17, 61-T3048 to 63-YRR-T3048 and fifth cross 65-T3021/2*CS(S)//PBW550 to 66-T3021/2*CS(S)//PBW550, 68-T3021, 71-T3021 to 72-YRR-T3021 were evaluated as Mn efficient lines. These lines can be used for further processing to introgress Mn efficiency and released at commercial level as Mn deficiency tolerant varieties.
Open Access
Growth and development of wheat (Triticum aestivum L.) genotypes as affected by drought stress and PGRs
(Punjab Agricultural University, Ludhiana, 2017) Aparjot Kaur; Thind, S.K.
The most important challenge in production of most of the crops including wheat (Triticum aestivum L.) is drought stress. Presently, growth and development of wheat genotypes (HD2967, PBW660, WH1105 and PBW658) as effected by drought stress and plant growth regulators like cytokinins [Kinetin (Kn) and Benzyl adenine (BA)] on various morpho-physiological and biochemical parameters under the lab conditions were studied to select the best concentration of Kn (@ 10, 20 and 40mg/L) and BA (@ 25 and 50mg/L). Drought stress in laboratory was induced by PEG-6000 creating -0.4MPa of stress. Under laboratory conditions, Kn@40mg/L and BA@50mg/L was performed better as compared to lower concentrations of Kn and BA tested and these were studied in combination with osmoprotectants like [Trehalose (Tre) and Glycine Betaine (GB)] in different combinations like Kn@40mg/L along with Tre@1mM, Kn@40mg/L along with Tre@ 1.5mM, BA @50mg/L along with Tre@1mM, BA @50mg/L along with Tre @ 1.5mM, Kn@40mg/L along with GB 50mM, Kn@40mg/L along with GB100mM, BA @50mg/L along with GB 50mM, BA @50mg/L along with GB 100mM in the field experiments on three wheat genotypes (HD2967, PBW660 and WH1105. Drought stress significantly reduced various morpho-physiological parameters like Relative Growth rate (RGR), Specific leaf area (SLA), Relative leaf water content (RLWC) and photosynthetic gas exchange parameters like net photosynthetic rate (NPR), transpiration rate (TR), stomatal conductance (SC) and intercellular CO2 concentration (ICC) at vegetative as well as flag leaf stage. Cytokinins along with different concentrations of osmoprotectants significantly decreased the negative effect of drought stress on various morpho-physiological parameters. Significant negative effect of drought stress was studied on biochemical parameters like Hill reaction activity, MDA content, membrane stability and cell viability. Drought stress significantly increased the photosynthetic pigments like chlorophyll and carotenoid content. Drought stress significantly increased the total soluble sugars, reducing sugars and decreased the non-reducing sugars. Enzymatic activities of various antioxidants like SOD, catalase, APx, DHAR and MDHAR were increased significantly under drought stress. Nonenzymatic ROS were alleviated significantly under drought stress and by application of cytokinins in combination with osmoprotectants. Under drought stress a significant reduction in yield contributing parameters like number of kernels per spike, number of productive tillers/m2, peduncle extrusion, thousand grain weight, grain yield/m2, biological yield/m2 and harvest index was recorded. Cytokinins in combination with different concentrations of osmoprotectants significantly ameliorated the negative effect of drought stress. From among the tested combinations, Kn@40mg/L in combination with Tre@ 1.5mM had more pronounced effect in ameliorating the adverse effect of drought stress on yield contributing parameters of selected wheat genotypes.

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