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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 Restricted Physiological basis of nitrogen use efficiency in maize (zea maysl.) at various rates of applied nitrogen(PAU, 2012) Amandeep Kaur; Bedi, SeemaField and laboratory experiments were conducted at Punjab Agricultural University, Ludhiana during kharifseason in the years 2009 and 2010 respectively to study the physiological basis of nitrogen use efficiency in maize (Zea mays L.) at various rates of applied nitrogen. Six maize genotypes (hybrids and their parents) i.e., long duration PMH1 (parents LM13, LM14) and short duration JH3459 (parents CM143, CM144) were raised under five nitrogen levels viz; recommended (RDN), RDN+25%, RDN+50%, RDN-25% and RDN-50% respectively. Various ecophysiological traits viz; leaf area, leaf area index (LAI), fraction of PAR intercepted by plants (FRI), intercepted photosynthetically active radiation (IPAR), radiation use efficiency (RUE) were significantly improved with the application of nitrogen at higher than the recommended rates in both long and short duration genotypes. Low nitrogen levels increased anthesissilking interval and shortened the duration of grain filling. It also caused a reduction in grain yield and its determinants mainly harvest index, 100-kernel weight, cob weight, above ground biomass, shelling percentage, cob length and diameter, number of kernel rows per cob and number of kernels per cob. The various physiological traits such as plant height, crop growth rate, relative growth rate, dry matter accumulation, root-shoot ratio etc. were significantly increased with the application of 25% and 50% higher nitrogen than the recommended. The applied nitrogendose also affected the content of various biochemical constituents (total soluble sugars, total soluble proteins, total starch content, chlorophyll content as well as the activity of various enzymes viz., nitrate reductase (NR), glutamine synthetase (GS), glutamate synthase (GOGAT) and PEP carboxylase). Path coefficient analysis showed that various traits such as RUE, LAI, FRI, IPAR, GS and NR activity had the maximum positivedirect contribution to grain yield in both set of maize genotypes (long and short duration). Therefore, these traits should be used as target traits to improve maize grain yield at both high and low nitrogen levels. The various quality parameters (starch, proteinand oil) in grains of both long and short duration genotypes were maximum in the treatment RDN+50%. Aminoacid content (total free amino-acids, tryptophan and methionine content) was significantly decreased with the decrease in nitrogen (RDN-25%; RDN-50%) than the recommended. In contrast, there was a decreasing pattern in nitrogen use efficiency (NUE), nitrogen remobilization efficiency (NRE) and nitrogen harvest index (NHI) values with increasing fertilizer rates in both long and short duration genotypes. Hybrids i.e. PMH 1 (long duration) and JH 3459 (short duration) were more responsive to variations in nitrogen supply than their female and male parents. Moreover, the high nitrogen use efficiency for hybrids (PMH1, JH3459) as compared to their parents (LM13, LM14 ; CM143, CM144) was associated with greater PAR interception during the growth period , high radiation use efficiency (RUE), more harvest index (HI), high photosynthetic capacity associated with increased acitivity of PEP carboxylase enzyme and high chlorophyll content in leaves, high nitrogen metabolic efficiency, increased activity of nitrogen metabolism enzymes (nitrate reductase, glutamine synthetase and glutamate synthase) leading to higher nitrogen harvest in dex. Keywords:GOGAT, GS, maize, nitrogen, NR, NUE, PAR, PEP carboxylase, RUE, yieldThesisItem Restricted REGULATION OF SENESCENCE THROUGH THE APPLICATION OF PLANT GROWTH REGULATORS AND NUTRIENTS IN RELATION TO PRODUCTIVITY IN SOYBEAN (Glycine max L. Merrill)(Punjab Agricultural University, Ludhiana, 2010) Kaur, Jasdeep; Kaur, JagmeetSoybean called ‘Miracle Bean’ belongs to family Fabaceae, contains 40% proteins and 20% edible oil. A striking feature of maturing soybean is decline of assimilatory capacities due to growing reproductive structures and is characterized by syndrome of physiological changes that include decline in foliar N, protein, chlorophyll and photosynthetic activity culminating in leaf abscission. The regulatory signals exchanged between the parts of soybean plant during development are affected by endogenous levels of hormones and possibly nutrient fluxes. The exogenous application of plant growth regulators and nutrients was done to study the senescence behavior in soybean. The treatments comprised of control (no spray), foliar application of SNP @150 and 200 µM, ethrel @ 150 and 200 µgml-1, calcium chloride @ 1 and 2 mM and sodium selenite @10 and 20 µgml-1. The treatments were applied in combinations of three stages vis-à-vis preflowering (V), pod initiation (P) and grain filling (G). Various observations pertaining to the morpho-physiological, biochemical and yield attributes were recorded at various growth stages. The morpho-physiological traits vis-à-vis plant height, root length, leaf characteristics, canopy characteristics and biomass accumulation studied at 60, 80, 100 and 120 DAS; were effectively enhanced by V+P+G application of SNP 200µM and P+G application of sodium selenite 20µgml-1. Also, the application of SNP 200µM (V+P+G) and sodium selenite 20µgml-1 (P+G) gave best results in terms of yielding attributes viz. pod count, 100 seed weight and seed yield. The photosynthetic pigments and activity along with storage biomolecules (total soluble sugars and starch) exhibited maximum change with SNP 200µM (V+P+G) and sodium selenite 20µgml-1 leading to enhanced production of photosynthates and accumulation of photoassimilates. The activities of antioxidant enzymes vis-à-vis catalase, peroxidase and superoxide dismutase concomitant with proline accumulation was putatively enhanced with the application of SNP 200µM (V+P+G) and sodium selenite 20µgml-1 (P+G) thereby counteracting the senescence induced oxidative stress. Also, the treatment with SNP 200µM elicited the activation of high molecular weight proteins in the leaves at 80 DAS. Conversely, higher concentration of ethrel at all treatment combinations depicted reduction in morpho-physiological traits, intense loss of chlorophyll and membrane integrity, lesser production of sugars and starch and reduced antioxidants contributing towards much reduced yield. Therefore, NO donor SNP 200µM (V+P+G) and sodium selenite 20µgml-1 (P+G) behaved as anti-senescence growth substance.ThesisItem Open Access COMPETITIVE ABILITY OF DIFFERENT WHEAT VARIETIES AGAINST Phalaris minor (Retz.) IN RELATION TO CROP GEOMETRY(Punjab Agricultural University, Ludhiana, 2011) Neeraj SharmaA field investigation was conducted at Students’ Research Farm, Deptt. of Agronomy, Punjab Agricultural University, Ludhiana during rabi 2010-11 to study the competitive ability of different wheat varieties against Phalaris minor (Retz.) in relation to crop geometry. The experiment was conducted using Split Plot Design with four replications. Three spacings (15cm, 22.5cm and 22.5cm × 22.5cm) and two weed control methods (sprayed and unsprayed) were kept in main plots and four wheat varieties viz: PBW 550, DBW 17, PBW 621 and WH 542 were kept in sub plots. The weed count (118 and 130/m2) and weed dry weight (22.6 and 24.0q/ha) was found to be significantly less at harvest under bi-directional (22.5cm × 22.5cm) sowing and closer (15cm) sowing, respectively as compared to normal 22.5cm sowing which resulted in increased grain yield i.e. 56.5q/ha and 52.5q/ha in bidirectional and closer sowing respectively. The plots sprayed with herbicide showed significantly less weed count (112/m2) and weed dry matter (21.5q/ha) at harvest which resulted in increased grain yield in sprayed plots (57.9 q/ha) as compared to unsprayed plots (45.3q/ha). Among four wheat varieties, PBW 621 and PBW 550 were at par with each other in terms of grain (57.1 and 55.4 q/ha) and straw (86.5 and 78.8 q/ha) yield due to more number of effective tillers/m2 (445 and 416), ear length (8.7 and 7.7cm), numbers of grains per ear (53.7 and 50.5) and thousand grain weight (39.1 and 38.2 g) respectively. The weed count (120 and 126/m2) and weed dry matter (22.4 and 23.2 q/ha) was found to be significantly less at harvest for wheat variety PBW 621 and PBW 550, respectively due to more leaf area index and number of tillers/m2 recorded at different growth stages of wheat and proved more competitive against Phalaris minor as compared to DBW 17 and WH 542.ThesisItem Open Access INFLUENCE OF BENZYLAMINOPURINE AND SALICYLIC ACID ON MORPHO-PHYSIOLOGICAL AND SOME BIOCHEMICAL PARAMETERS OF WHEAT (Triticum aestivum L.) UNDER WATER STRESS(Punjab Agricultural University, Ludhiana, 2010) RadhikaThe influence of Benzylaminopurine (BAP) and Salicylic acid (SA) on morphophysiological and some biochemical parameters of wheat (Triticum aestivum L.) genotypes (PBW 343 and PBW 527) under water deficit conditions was studied. The PEG (6000) induced water stress (-.2MPa, -.4MPa and -.6MPa) had markedly reduced the root and shoot traits (coleoptile length, seminal root number, seminal root length, number of leaves, total leaf area, seedling fresh weight and seedling dry weight) at 10 DAS under laboratory conditions. Foliar application of BAP and SA given at the 7 DAS had partially ameliorate the PEG induced water stress. Water stress given at the tillering stage and the boot leaf stage had significantly reduced the plant height, hill reaction activity, photosynthetic pigments, starch, proteins and significantly induced the sugars, free amino acids, proline, water saturation deficit, relative saturation deficit, acid invertase activity and membrane permeability in the leaves of the studied genotypes at both 70 DAS and 100 DAS. Water stress imposed at the tillering stage resulted in more yield loss as compared to the stress given at the boot leaf stage. Foliar application of BAP @100 μg ml-1 given at the vegetative stage under water deficit conditions had showed the stress ameliorative effect and foliar application of SA @ 30 μg ml- 1 given at the vegetative stage had more growth promotary effect as compared to the application given at the anthesis stage under water deficit conditions, whether the stress was given at the tillering stage or the boot leaf stage.ThesisItem Open Access ThesisItem Open Access SELECTION CRITERIA FOR COMBINING HIGH GRAIN YIELD AND PROTEIN CONTENT BASED ON NITROGEN PARTITIONING EFFICIENCY IN WHEAT (Triticum aestivum L.)(Punjab Agricultural University, Ludhiana, 2010) Sidhu, Sukhpreet KaurThis study was designed to identify selection criteria for the simultaneous improvement of grain yield and grain protein concentration in wheat (Triticum aestivum L.). Three wheat cultivars namely PBW-550, PBW-502 and PBW-343 were sown on 2nd week of November under two nitrogen levels (120 and 180 kg ha-1). Results showed that Cv.PBW-550 found to have maximum remobilization efficiency (78.98%), grain protein yield (90.33 g m-2) and nitrogen harvest index (0.602). This cultivar had higher grain yield (57.34 q ha-1) averaged over both nitrogen level due to maximum number of spikes per plant (7.5), number of kernels per spike (65.67) and 1000- kernel weight (44.43 g) as compared to Cv.PBW-502 and PBW-343.This indicate that Cv. PBW-550 expressed high levels of both traits concurrently. Pearson correlation analysis showed significant positive correlation with grain yield and vegetative nitrogen at anthesis + 12 days (r = 0.9693**), vegetative nitrogen at anthesis + 4 days (r = 0.8527**), accumulated nitrogen (r = 0.8596**), accumulated dry matter (r = 0.7313**) at post anthesis stage. Correlation analysis also indicate significant positive correlation between grain protein concentration (r = 0.8236**), harvest index (r = 0.9833**), total plant nitrogen (r = 0.9710**) and grain protein yield (r = 0.9067**) at physiological maturity. Regression line between grain yield and grain protein concentration showed significant positive relationship (R2 = 0.6948).The correlation and path analysis revealed that the direct effect of vegetative nitrogen at maturity was more (P9 11= 0.5329) followed by remobilization efficiency (P10 11=0.2072) on grain yield. The regression model showed significant positive correlation between grain yield and growing degree days accumulated during booting stage (R2= 0.4709).These results indicated that Cv.PBW-550 showed 12.96% increase in grain yield and 19.62% increase in grain protein concentration due to its high nitrogen remobilization and partitioning efficiency. Nitrogen uptake and nitrogen partitioning function as separate and independent physiological systems in wheat plants. Therefore, improvement in both grain protein percentage and grain yield realized by manipulating nitrogen uptake and its partitioning separately.
