Thumbnail Image

Thesis

Browse

2012 - 20162
Reset filters
Subject: Botany × Author: Manpreet Kaur × End date: 2019 × Type: Thesis × Thesis Type: M.Sc ×
Reset filters

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    ThesisItemRestricted
    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 Ghai
    The 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.
  • Thumbnail Image
    ThesisItemOpen Access
    Morpho-physiological characterization of Iranian wheat (Triticum aestivum L.) land races
    (Punjab Agricultural University, Ludhiana, 2016) Manpreet Kaur; Sarlach, R.S.
    The present investigation entitled “Morpho-physiological characterization of Iranian wheat (Triticum aestivum L.) land races” was carried out at Punjab Agricultural University, Ludhiana during 2014-15 and 2015-16 with the objectives to evaluate the Iranian wheat germplasm for morpho-physiological traits and screening of germplasm for drought and micronutrient deficiency tolerance. The experiment was laid out in augmented design. Data on plant height, number of tillers per meter row length, days to flowering, days to maturity, canopy temperature, chlorophyll content, stay green habit, number of grains per spike, 1000 grain weight, number of spikelets per spike and grain yield were recorded. During 2014-15, set of 249 Iranian wheat germplasm lines along with checks were evaluated for morphophysiological and yield component traits under irrigated conditions. Frequency distribution for the germplasm set showed wide variation for all morpho-physiological and yield components traits. During 2015-16, set of 249 Iranian wheat land races along with 15 checks were evaluated for various morpho-physiological and yield component traits under irrigated and rainfed conditions. The drought environment was created by withholding the irrigation. Analysis of variance for morpho-physiological traits and yield revealed highly significant (P<0.01) differences among the entries under both environments, indicating the genetic diversity in the set. The mean squares due to treatments were highly significant for all the traits under both rainfed and irrigated environments. On the basis of stress tolerance index (STI) value, genotypes IR243, IR121, IR216, IR175, IR2, IR244, IR88, IR20, IR19, IR213, IR141, IR54, IR242, IR12, IR246, IR75, IR207, IR181, IR87, IR21 were categorized as drought tolerant. Another experiment was sand culture using half seeds to assess tolerance to micronutrient deficiencies. Murashige and Skoog (MS) macro-salts nutrient solution was used to create micronutrient deficiency until 40 days of sowing. The observations on root and shoot length, fresh and dry weight were recorded after 40 days. Frequency distribution was found to be approximately normal for all seedling traits under micronutrient deficiency. Iranian landraces viz; IR26, IR55, IR83, IR30, IR13, IR40, IR191, IR20, IR4, IR16 were found to be the best landraces tolerant to micronutrient deficiency on the basis of seedling dry weight.