Thumbnail Image

M. Sc. Dissertations

Browse

20073
Reset filters
Subject: Plant Physiology × End date: 2007 × Start date: 2007 ×
Reset filters

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    ThesisItemOpen Access
    Starch metabolism and end use quality of durum wheat in response to high temperature stress
    (CCSHAU, 2007) Bansal, Kavita; Munjal, Renu
    The present experimentation was carried out on durum wheat to study the physiological and biochemical basis of high temperature induced changes in sucrose to starch conversion. Effect of high temperature stress was determined on grain quality and starch metabolism in two durum wheat varieties WH 896 and WH 912. The investigation involved pot studies under screen house conditions during the year 2005-06. In this study, high temperature was induced by shifting the pots to polyhouse after heading. Heat degree days (HDD) were used to quantity the magnitude of heat stress to which these two durum wheat varieties were exposed during the second half of crop growth i.e. from days of heading (DOH) to days of physiological maturity (DOPM) and it is expressed as sum of daily mean temperature during particular period of crop growth. High temperature decreased functioning of various physiological parameters of the plants such as chlorophyll, chlorophyll fluorescence, chlorophyll stability index, membrane thermostability, osmotic potential and dry matter accumulation in grains. The detrimental effect of high temperature on various grain yield and quality characteristics such as grain shriveling score, grain hardness, grain weight/spike, grain number, test weight (1000-grains weight), β-carotene and total protein were also reflected. However, sedimentation value increased under high temperature treatment. Besides these, biochemical parameters such as total soluble sugars, reducing sugars, non-reducing sugars, protein, sucrose, starch and amylopectin were also reduced under high temperature stress except amylose. The enzymes and metabolites involved in starch biosynthesis also declined under high temperature treatment. Among enzymes, soluble starch synthase activity was reduced maximum as compared to other enzymes activities and among metabolites, ADP-glucose and UDP-glucose reduced maximum than other metabolites under high temperature stress. Results of present experiment show that variety WH 896 is more tolerant to heat stress than WH 912 in manners of various physiological, biochemical and quality characteristics parameters when they were exposed to same degree of high temperature stress
  • Thumbnail Image
    ThesisItemOpen Access
    Physiological and biochemical effects of salicylic acid in rice (Oryza sativa L.) under cadmium stress
    (CCSHAU, 2007) Son, Duong Hoang; Patel, A. L.
    The present study entitled “Physiological and biochemical effects of salicylic acid in rice (Oryza sativa L.) under cadmium stress” was conducted during Kharif 2006 in pots in the screen house, Department of Botany and Plant Physiology, CCS Haryana Agricultural University, Hisar. The experiment was laid out in factorial completely randomized design with three replications. The treatments consisted of four levels of SA (0 mM as control, 100 mM seed treatment, 0 mM as water spray at booting stage and 100 mM spray at booting stage) and three levels of Cd viz. 0, 250 and 500 mM kg-1 soil applied after 30 days of sowing. Growth of rice plant in terms of plant height, number of tillers and leaf area at flowering, and total dry weight of shoot and its component (stem, leaf and panicle) at harvest decreased under Cd stress. SA spray treatment proved better than SA seed treatment in partially improving these parameters under Cd stress. Cd stress significantly reduced the ΨW, ΨS, RWC, rates of photosynthesis, transpiration and stomatal conductance, and contents of total chlorophyll, total soluble carbohydrate and total soluble protein in leaf at flowering. SA spray treatment being better than seed treatment partially improved these parameters under Cd stress. Considerable increase in the contents of total free amino acids, free proline, malondialdehyde (lipid peroxidation) and percentage of membrane injury in leaf at flowering, and the Cd concentration in shoot and its components (Stem, leaf and panicle) at harvest were observed under Cd stress. SA spray treatment being more effective than seed treatment counteracted the Cd-induced elevation on these parameters Cd stress adversely affected the yield and its components number of panicles per plant, number of spikelets per panicle, filled grain percentage and 1000-grain weight) over control. Among these, number of panicles per plant and number of spikelets per panicle were more sensitive yield components responsible for decrease in grain yield under Cd stress. Grain yield and its components were higher in SA treated plants. SA spray being better than SA seed treatment partially alleviated the grain yield more under 250 mM of Cd than under 500 mM of Cd. In brown rice, starch and amylose content decreased but Cd concentration increased under Cd stress. Application of SA decreased the Cd concentration and showed partial improvement in starch and amylose content in brown rice under Cd stress.
  • Thumbnail Image
    ThesisItemOpen Access
    Studies on salicylic acid induced amelioration of salinity stress in mungbean [Vigna radiata (L.) Wilczek]
    (CCSHAU, 2007) Pooja; Sharma, K.D.
    The study entitled, “Studies on salicylic acid induced amelioration of salinity stress in mungbean [Vigna radiata (L.) Wilczek]” was conducted during kharif season of 2006 at screen house, Department of Botany and Plant Physiology, CCS Haryana Agricultural University, Hisar. The experiment was laid out in factorial CRD with three replications. The treatment consisted of two levels of salinity stress (4 and 6 dSm-1) maintained after germination and two concentration of salicylic acid (0.25 and 0.50 mM) applied as foliar spray at flower initiation. The observations were recorded 2 and 6 days after salicylic acid (SA) spray. Salinity stress decreased the growth of mungbean in terms of plant height, dry matter accumulation and leaf area. However, treatment with SA increased the growth parameters under salinity stress. All the plant water status parameters i.e. w, s and RWC decreased with increasing level of salinity stress. Application of SA improved the plant water status irrespective of salinity levels. Gaseous exchange studies i.e. rate of photosynthesis, transpiration and stomatal conductance get reduced under salinity stress. Higher concentration of SA was more effective to brought consecutive improvement in gaseous exchange under salinity. Membrane injury and lipid peroxidation enhanced under salinity stress but salicylic acid application increased the membrane stability and decreased MDA production. Biochemical metabolites i.e. chlorophyll and protein content declined under salinity stress. However, free proline, total soluble carbohydrates and free amino acids content showed sharp rise under salinity stress. Exogenous SA application increased all the above biochemical metabolites under salinity. The ionic composition i.e. Na+, Cl- and SO4- increased but decline in K+ content in leaves under salinity stress. Salicylic acid reversed the accumulation trend under stressed condition. Seed and biological yield reduced significantly by decreasing yield attributing characters i.e. number of effective pods, seeds per plant and test weight under salinity stress. Salicylic acid improved the yield and its attributes by maintaining plants water status and various physiological and biochemical processes.