Thumbnail Image

Theses

Browse

20212
Reset filters
Subject: Plant Physiology × Author: Gayatri Kumari × Start date: 2002 × Type: Thesis × Thesis Type: M.Sc ×
Reset filters

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    ThesisItemOpen Access
    Evaluation of physiological and biochemical traits in sorghum (Sorghum bicolor L.) varieties during summer season
    (CCSHAU, Hisar, 2021-07) Gayatri Kumari; Sarita Devi
    The present investigation entitled “Evaluation of physiological and biochemical traits in sorghum (Sorghum bicolor L.) varieties during summer season” was evaluated in the screen house during the summer season of 2021. Before sowing, the desired levels of salt stress (control, 5, 8 and 10 dS m-1) were maintained in all pots at its saturation percentage. Seeds of Sorghum bicolor L. were grown in pots under controlled conditions on 26th February 2021. All the varieties survived well upto 8 dS m-1 and only one variety (HJ 541) maintained its growth upto 10 dS m-1 of salt stress. Sampling for growth parameters was made at 30, 60 DAS and at 50% flowering stage and physiological and biochemical parameters were estimated at the time of 50% flowering. Germination and growth studies declined with the augmentation of salt stress at all the stages. Highest dry weight (0.7, 7.1 and 9.1 g/plant) and leaf area (211.9, 270.5 and 278.5 cm2/plant) was estimated in HJ 541 respectively, at 30, 60 DAS and at the time of 50% flowering. Salinity susceptibility index (SSI %) was calculated less than one in HJ 541 at 30, 60 DAS and at 50% flowering stage. Similarly, plant water status, total chlorophyll content, and photochemical quantum yield also showed declining trend with the imposition of salt stress from control to 8 dS m-1 in all the varieties. At 8 dS m-1 of salt stress, less negative values of osmotic potential and higher RWC (%) was maintained by HJ 541 at 50% flowering stage. Percent decline in total chlorophyll content (26.5%), Fv/Fm (15%), TSS (18.2%) and assimilation rate (35.8%) was noticed in HJ 541 at 8 dS m-1. The genotypic mean values ranged from 6.5 - 8.0 mmole H2O m-2s-1 and 0.04 – 0.06 m mole H2O m-2s-1 respectively in transpiration rate and stomatal conductance. Reversibily, RSI (%) increased with every increment of salt stress at 50% flowering stage. Osmolyte accumulation and specific activity of antioxidative enzymes enhanced gradually at 5 dS m-1 and after that a sharp increase was noticed in all varieties at 8 dS m-1 of salt stress. Per cent increase was on higher side at 8 dS m-1 of salt level in HJ 541 at 50% flowering stage viz. proline (61.5%), glycine betaine (60.2%), and SOD (31.1%) CAT (69.4%), POX (34.2%) over their respective control. At 50% flowering, the fresh weight of HJ 541 was 4.5% higher over HJ 513 being at par with each other at 8 dS m-1 of salt stress. Based on the dry weight, physiological and biochemical parameters it was concluded that HJ 541 performed better upto 8 dS m-1, being the only variety that survived at 10 dS m-1 during summer season, hence it is a promising cultivar for salt tolerance.
  • Thumbnail Image
    ThesisItemOpen Access
    Evaluation of physiological and biochemical traits in sorghum (Sorghum bicolor L.) varieties during summer season
    (CCSHAU, Hisar, 2021-07) Gayatri Kumari; Sarita Devi
    The present investigation entitled “Evaluation of physiological and biochemical traits in sorghum (Sorghum bicolor L.) varieties during summer season” was evaluated in the screen house during the summer season of 2021. Before sowing, the desired levels of salt stress (control, 5, 8 and 10 dS m-1) were maintained in all pots at its saturation percentage. Seeds of Sorghum bicolor L. were grown in pots under controlled conditions on 26th February 2021. All the varieties survived well upto 8 dS m-1 and only one variety (HJ 541) maintained its growth upto 10 dS m-1 of salt stress. Sampling for growth parameters was made at 30, 60 DAS and at 50% flowering stage and physiological and biochemical parameters were estimated at the time of 50% flowering. Germination and growth studies declined with the augmentation of salt stress at all the stages. Highest dry weight (0.7, 7.1 and 9.1 g/plant) and leaf area (211.9, 270.5 and 278.5 cm2/plant) was estimated in HJ 541 respectively, at 30, 60 DAS and at the time of 50% flowering. Salinity susceptibility index (SSI %) was calculated less than one in HJ 541 at 30, 60 DAS and at 50% flowering stage. Similarly, plant water status, total chlorophyll content, and photochemical quantum yield also showed declining trend with the imposition of salt stress from control to 8 dS m-1 in all the varieties. At 8 dS m-1 of salt stress, less negative values of osmotic potential and higher RWC (%) was maintained by HJ 541 at 50% flowering stage. Percent decline in total chlorophyll content (26.5%), Fv/Fm (15%), TSS (18.2%) and assimilation rate (35.8%) was noticed in HJ 541 at 8 dS m-1. The genotypic mean values ranged from 6.5 - 8.0 mmole H2O m-2s-1 and 0.04 – 0.06 m mole H2O m-2s-1 respectively in transpiration rate and stomatal conductance. Reversibily, RSI (%) increased with every increment of salt stress at 50% flowering stage. Osmolyte accumulation and specific activity of antioxidative enzymes enhanced gradually at 5 dS m-1 and after that a sharp increase was noticed in all varieties at 8 dS m-1 of salt stress. Per cent increase was on higher side at 8 dS m-1 of salt level in HJ 541 at 50% flowering stage viz. proline (61.5%), glycine betaine (60.2%), and SOD (31.1%) CAT (69.4%), POX (34.2%) over their respective control. At 50% flowering, the fresh weight of HJ 541 was 4.5% higher over HJ 513 being at par with each other at 8 dS m-1 of salt stress. Based on the dry weight, physiological and biochemical parameters it was concluded that HJ 541 performed better upto 8 dS m-1, being the only variety that survived at 10 dS m-1 during summer season, hence it is a promising cultivar for salt tolerance.