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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 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.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 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 EFFECT OF FOLIAR APPLICATION OF POTASSIUM AND MAGNESIUM ON GROWTH AND YIELD OF SUMMER MUNGBEAN (Vigna radiata (L.) Wilczek) UNDER WATER STRESS CONDITIONS(PUNJAB AGRICULTURAL UNIVERSITY, 2011) maninder kaur; Parmar, UshaThe present investigation was undertaken with the objective to understand the phenological response of summer mungbean genotypes SML 1082 and SML 1168 to moisture stress at vegetative, flower initiation and pod initiation stages and also to understand the influence of potassium and magnesium on various morphological, physiological and biochemical parameters. The experiment was carried out on plants grown under field conditions. Various morpho-physiological parameters viz. plant height, number of leaves plant-1, leaf area plant-1, LAI, LAD, SLW, RWC, CGR and RGR decreased with moisture stress whereas root length increased under moisture stress. All the yield contributing parameters viz. number of clusters plant-1 and number of pods cluster-1 decreased maximum with moisture stress given at flower initiation stage whereas number of seeds pod-1, pod length, 100 seed weight, total yield plant-1 decreased maximum when moisture stress was given at pod initiation stage. Biochemical parameters viz. total chlorophyll content, Hill reaction activity, carotenoid content, total soluble proteins and nitrogen content decreased with moisture stress while proline content and total soluble sugars increased under moisture stress given at any stage. Foliar spray of 2%KNO3 and 50ppmMgSO4 ameliorated the effect of moisture stress in both the genotypes SML 1082 and SML 1168. 2%KNO3 was more effective as compared to 50ppmMgSO4 in most of the parameters. On the basis of above mentioned observations SML 1082 was more sensitive to moisture stress as compared to SML 1168.ThesisItem Restricted Screening of chickpea (Cicer arietinum L.) genotypes to salinity tolerance(Punjab Agricultural University, Ludhiana, 2013) Pavneetpal Kaur; Jagmeet KaurThe present investigation was undertaken to screen the chickpea genotypes for the growth behavior and alteration in yield contributing traits during salinity stress. Twenty two diverse chickpea genotypes were evaluated for salinity tolerance. The experiment was conducted in plastic pots raised under rain out shelter. The treatments comprised of control, 20mM and 30mM NaCl applied in split doses: 50% at the time of sowing and remaining at 15 days after sowing. The observations on various physiological and biochemical traits were recorded at 65 DAS (vegetative stage), 90 DAS (flower initiation) and 110 DAS (pod initiation) and yield attributes at maturity. Salt stress profoundly affected the growth attributes. All the genotypes depicted reduction in plant height, leaf area and biomass efficiency. The photosynthetic pigments, activity of nitrate reductase and relative leaf water content was also reduced in response to salt application with effect being more pronounced in identified salt sensitive genotypes (ICC15868 and GL26054) as compared to salt tolerant ones (BG1053, L550, ICC8950 and ICCV10). Lipid peroxidation increased with both the salinity levels. Under saline conditions higher accumulation of osmotic solute proline, total proteins and protein fractions was observed with tolerant genotypes in contrast to sensitive genotypes. Salt imposed stress finally caused a higher decline in yield attributes of sensitive genotypes as compared to tolerant. The genotypes viz. BG 1053, L550, ICC8950 and ICCV10 were identified as salt tolerant.
