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ThesisItem 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, SeemaDirect 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.ThesisItem Restricted SALICYLIC ACID INDUCED CHANGES IN SOME PHYSIOLOGICAL AND BIOCHEMICAL PARAMETERS IN MASHBEAN (Vigna mungo L. Hepper) GENOTYPES GROWN UNDER SALINITY(PAU Ludhiana, 2012) Manpreet Kaur; Navita GhaiThe present investigation was undertaken to study the effect of salicylic acid on physiological and biochemical parameters in salt sensitive (KUG 363 and KUG 310) and salt tolerant (KUG 529 and KUG 502) mashbean genotypes, along with a check variety (UL 338) grown under NaCl (30mM and 45mM) stress. The plants were grown in plastic pots kept under a rain-out shelter. NaCl was applied in split dose: 50% at the time of sowing and remaining 50% at 15 days after sowing (DAS). Salicylic acid (SA) @ 0.5 mM and 1.0 mM was applied as a foliar spray at 25 DAS. Data on various physiological and biochemical changes was recorded at 35 (vegetative stage), 50 (flowering stage) and 65 (pod setting stage) DAS. Salt stress decreased the leaf area and plant dry biomass of all the genotypes at various stages of development. The decrease in plant dry biomass led to reduction in relative growth rate and crop growth rate. Sensitive as well as tolerant genotypes showed a sharp increase in membrane permeability under saline conditions. NaCl caused a decrease in photosynthetic pigments and increase in levels of hydrogen peroxide and malondialdehyde content. Under saline conditions, all the genotypes showed a higher accumulation of osmotic solute proline, with tolerant genotypes accumulating more amount than sensitive ones. Antioxidant enzymes like catalase and ascorbate peroxidase showed a decrease under saline conditions. However, peroxidase activity was increased under salt stress. Maximum increase was shown in salt sensitive genotypes. Reduction in yield contributing parameters like number of pods plant-1, number of seeds per pod, 100 seed weight and seed yield plant-1 was observed at both the levels of salinity. SA treatments had a pronounced ameliorative as well as, growth promoting effect under saline conditions. The ameliorative effect of SA was observed as increase in leaf area, relative leaf water content, water potential of leaves and photosynthetic pigments in salt-stressed plants. SA treatments increased the biosynthesis of proline under salt stress. Foliar application of SA enhanced the level of antioxidant system (catalase and ascorbate peroxidase) in mashbean plants under NaCl stress and reduced the hydrogen peroxide and malondialdehyde content. The reduction in yield and yield contributing parameters was also less in SA-treated salt-stressed plants as compared to non saline controls. However, tolerant genotypes (KUG 529 and KUG 502) and check variety (UL 338) were able to tolerate high salinity and responded better to the application of SA as compared to sensitive genotypes probably due to improved growth, metabolism and enhanced antioxidant system. Lower concentration of SA (0.5 mM) proved to be more effective to ameliorate the adverse effects of salt stress.ThesisItem Open Access PHYSIOLOGICAL AND MOLECULAR BASIS OF SEED PRIMING IN LATE SOWN WHEAT (Triticum aestivum L.)(PAU Ludhiana, 2011) Ambalika; Geeta, BassiSeed priming is an important physiological seed quality enhancement method. It provides a low-cost practical solution to sow seed in stress conditions. Abiotic stresses like low temperature and inadequate moisture during sowing season, many a times result in poor germination and poor plant stand leading to drop in crop yield. To harvest the full genetic potential, seeds must germinate and seedlings emerge quickly and uniformly throughout the field so that light, water and other soil nutrients may be utilized with maximum efficiency. However, this may not always happen in nature. Most of the major crops grown under stressed conditions can benefit substantially from pre- sowing seed priming treatment. In Punjab during sowing, prevailing low temperature, closure of canals or scanty rains result in poor germination and poor crop stand of late sown wheat. Therefore, keeping in view the prospects of this technique, the present investigations were undertaken to observe the effect of seed priming on different physiological and molecular parameters in late sown wheat. PBW 509 is late sown wheat (Triticum aestivum L.) variety released by Punjab Agricultural University Ludhiana. Different hydration durations applied were 8h, 12h, 16h and 18h and it was found that hydration for 16 h as well as 18 h enhanced the physiological parameters and elevated biochemical and molecular parameters. It was also observed that primed seeds after germination of 24 and 48 h indicated higher values of molecular parameters.ThesisItem Open Access EVALUATION OF ROSE (Rosa hybrida L.) CULTIVARS FOR LANDSCAPE USE(PAU Ludhiana, 2011) Parget Singh; R. K., DubeyThe present experiment entitled, “Evaluation of rose (Rosa hybrida L.) cultivars for landscape use” was carried out at the Research Farm, Department of Floriculture and Landscaping, Punjab Agricultural University, Ludhiana during the year 2009-2011. The experiment comprised of 30 floribunda and 20 miniature cultivars. The maximum plant height (53.67 cm) was observed in cultivar ‘Banjaran’ and ‘Torch of Liberty’ (30.00 cm) in floribunda and miniature cultivars respectively. The maximum plant spread (90.83 cm) was recorded in floribunda cultivar ‘Brown velvet’. The floribunda cultivars ‘Summer Snow’, ‘Ahalya’ and miniature cultivars ‘Red Flush’ and ‘Red Ace’ were observed to be thornless. The foliage glossiness was observed in four floribunda and two miniature rose cultivars. Flower size was observed to be maximum in ‘Charleston’ (8.37 cm) and ‘Black Jade’ (5.23 cm) in floribunda and miniature cultivars respectively. Flower colour of the cultivars evaluated varied from Red, Purple, Yellow to Orange group. Maximum duration of flowering (141.33 days) was observed in ‘Brown velvet’ cultivar of floribunda. In case of miniature cultivars maximum duration of flowering (131.33 days) was observed in cultivar ‘My Valentine’. Maximum number of petals per flower was recorded in cultivars ‘Arunima’ (66) and ‘Rosy’ (100) in floribunda and miniature rose cultivars respectively. Seed setting was observed in seven floribunda rose cultivars and seven miniature rose cultivars.ThesisItem Open Access Physiological and biochemical basis for determining seed longevity in carrot (Daucus carota L.)(Punjab Agricultural University, Ludhiana, 2016) Manjeet Kaur; Bassi, GeetaThe present investigation was carried out at Seed Technology Centre, Punjab Agricultural University, Ludhiana. The freshly harvested foundation seed of carrot cv. Punjab Carrot Red was stored from June 2015 to June 2016 under different storage temperature conditions (ambient, cold room and refrigerator) in four different packaging materials (cloth bag, plastic bag 700 gauge, desiccator with silica gel and desiccator with drying beads). The initial moisture content of carrot seeds was 6.90%. Bimonthly observations with respect to physiological and biochemical seed quality parameters were conducted to determine the longevity and viability of the stored seeds. Based upon the observed results it was concluded that if the carrot seeds with MC of 5.5±1% to 5.8±1% stored in the desiccator containing drying beads or silica gel and stored in refrigerator (~5.9°C) with RH of 30.36±5% or cold room (~15.7°C) with RH of 56.76±5%, can maintain seed viability up to 12 months. It was also inferred that, under ambient temperature conditions (~29.4°C) at RH of 37.2±5% with MC of 6.7±1%, the carrot seeds can be stored for 12 months if packed in the cloth bag.ThesisItem Open Access Physiological variations in herbicide tolerance among Chickpea (Cicer arietinum L.) genotypes(Punjab Agricultural University, Ludhiana, 2016) Kawaljit Kaur; Jagmeet KaurThe present investigation was carried out in field area of the Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana during rabi season 2015-16 to evaluate the variations in herbicide tolerance in chickpea genotypes. A field experiment was conducted in factorial randomized block design using twenty four genotypes and three treatments (unsprayed, imazethapyr and carfentrazone-ethyl). According to our studies, both herbicides caused change in phenological development of plants. The early flowering and maturity was found in herbicide tolerant genotypes. Significant variations were recorded in physiological parameters (leghaemoglobin content, leaf area index, photosynthetic efficiency, hill reaction activity, cellular respiration and malondialdehyde content) during reproductive phase displaying that herbicides affect physiological processes in the plant. There was an upregulation in malondialdehyde content in sensitive genotypes. A negative effect of herbicidal treatments on yield attributes (yield/plant, pods/plant and 100-seed weight) was observed. From physiological parameters and yield attributes, genotypes were assorted as tolerant and sensitive from each treatment. Six genotypes (three sensitive GL 12021, GLW 125, GL 27023 and three tolerant GLW 11, GL 10047, PDG 4) following carfentrazone-ethyl treatment and (three sensitive JG 1362, GL 28203, GL 12021 and three tolerant GL 11026, GLW 44, PBG 5) following imazethapyr treatment were further evaluated for biochemical evaluation. It was shown that during reproductive phase, total soluble sugars, total proteins, total free amino acids and proline content in leaves were elevated in tolerant genotypes of each treatment. Anti-oxidative defence system was studied from leaves and it was found to be hiked in tolerant genotypes. This work emphasizes that genpotypes GLW 11, GL 10047, PDG 4 and GL 11026, GLW 44, PBG 5 are apt for the post-emergence herbicide tolerance.ThesisItem Open Access Viability studies on onion (Allium cepa L.) cv. Punjab Naroya seeds during storage(Punjab Agricultural University, Ludhiana, 2016) Paul, Amandeep; Bedi, SeemaRapid loss in viability of onion seeds during seed storage is a major problem. In the present study, seeds of onion (Allium cepa L.) cv. Punjab Naroya harvested in the month of June were subjected to three post harvest storage procedures, viz; refrigerator storage at (5⁰C; 30% RH) for 4 months (considered as fresh seeds), room temperature storage for 4 months (stored seeds) and accelerated aged seeds. Refrigerator stored seeds were subjected to accelerated ageing at (50º C; 90% RH) for 3, 6, 9 and 12 days respectively. The refrigerated stored seeds showed maximum germination percentage (94%) while seeds accelerated aged for twelve days gave least germination percentage (62%). As the duration of ageing increased, there was a marked reduction in seedling length, fresh and dry weight. All the ageing treatments resulted in membrane damage, as is evident from higher solute leakage in aged seeds. Besides physiological changes, significant changes in biochemical parameters were also observed due to ageing. Increase in ageing duration decreased the activities of enzymes viz; peroxidase, catalase and α-amylase. There was a reduction in contents of total starch and total soluble proteins whereas, the total soluble sugars and total free amino acids increased with accelerated ageing. The amount of ascorbic acid, α-tocopherol and DNA also reduced with accelerated ageing.ThesisItem Restricted Effect of proline and salicylic acid on germination of muskmelon (Cucumis melo L.) seeds at different temperatures(Punjab Agricultural University, Ludhiana, 2016) Sandeep Kaur; Gupta, NamartaIn this work, the effect of proline and salicylic acid on physiological and biochemical parameters of muskmelon (Cucumis melo L.) seeds c.v. Punjab Sunehri at different temperatures was studied. The low temperature has deleterious effect on seed germination and seed vigour parameters. Seeds of muskmelon were treated with different treatments (hydration, warm water and different concentrations of proline and salicylic acid) at 20˚C and 25˚C. Various estimations were done from the treated seedlings after 8 days of germination. All the seed treatments increased the physiological (percent germination, seedling length, seedling biomass, speed of germination, vigour index I and II) and biochemical parameters (total soluble sugars, total soluble proteins and activities of antioxidant enzymes) of seedlings as compared to control at 20˚C and 25˚C. But as far as electrolyte leakage was concerned, different treatments were effective in decreasing the leakage of electrolytes at both the temperatures. The results showed that Proline 20mM and salicylic acid 0.1mM were more effective as compared to proline 10mM and salicylic acid 0.5mM at both the temperatures. Thus, application of proline and SA could play an ameliorating role on low temperature stress tolerance by regulating and scavenging the free radicals produced by reactive oxygen species.ThesisItem Open Access Effect of plant growth regulators on manipulation of source-sink relationships in pigeonpea (cajanus cajan l.)(PAU, 2013) Pahwa, Kanchan; Ghai, NavitaField experiments were conducted at Punjab Agricultural University, Ludhiana during kharif season in the years 2010-11 and 2011-12 respectively with an objective to evaluate various groups of genotypes (early, mid, late and check) on the basis of pattern of growth, partitioning of dry matter, flower retention, growth efficiency and yield and to study the effect of foliar application of ethrel (100 and 200 μg ml -1 ) and cobalt chloride (10 and 15 μg ml -1 ) applied at vegetative and flowering stages on seed yield. Various morpho-physiological, biochemical and yield characteristics were analyzed at different developmental stages. Study conducted with early, mid, late and check genotypes of pigeonpea revealed marked differences in partitioning of assimilates to vegetative and reproductive parts at different stages of growth cycle. The higher CGR, RGR, leaf area, LAI, photosynthesis, stomatal onductance, pod set percentage in mid-duration group resulted in high yield. Further, reproductive efficiency of four mid-duration genotypes (AL 1578, AL 1593, AL 1702 and AL 201) was chemically manipulated by foliar application of ethrel and cobalt chloride. The parameters determining reproductive efficiency and yield were significantly improved due to reduction in flower abscission. Ethrel (100 and 200 μg ml -1) sprayed at vegetative stage and CoCl2(10 μg ml-1) sprayed at flowering stage efficiently improved seed yield and other biochemical traits through improved flower retention, pod formation , seed setting percentage and seed weight. Genotype AL 1578 exhibited high yield in all treatments including control as compared to all the genotypes. The leaves of treated plants exhibited higher level of chlorophyll, which provided better conditions for higher production of photosynthates to be utilized for grain yield due to larger sink resulting from increased branching and number of pods. The treatments also affected the content of various biochemical constituents (total soluble sugars, total soluble proteins, total starch content, total free amino acids, chlorophyll content as well as the activity of various enzymes viz., nitrate reductase (NR), invertase and PEP carboxylase). Correlation analysis showed significant positive relationships between plant height, crop growth rate, leaf area, number of pods/plant, pod set percentage, seed eight/plant, 100-seed weight and harvest index. Further, path analysis revealed leaf area, specific leaf weight and number of pods/plant had significant positive direct influence on yield. Path analysis of various biochemical traits with seed yield revealed that activities of nitrate reductase, total soluble proteins and total starch content in leaves and invertase activity, total starch in seeds showed positive direct effect on seed yield. These traits should be used as target traits to improve seed yield. Protein profiling in mature seeds revealed much denser bands in treated plants as compare to control and also number of bands were higher in treated plants. A study of pedicel anatomy revealed an increase in area of conducting tissues through PGRs application. This increase could be responsible for enhanced translocation of assimilates to flowers, thereby helping in their retention.
