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2017 - 201912020 - 20211
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Subject: Plant Physiology × Author: Chandra, Tanvi × Start date: 2015 × Type: Thesis ×
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    ThesisItemOpen Access
    Morpho-physiological and biochemical characterization of wheat varieties (Triticum aestivum L.) sown at differential time intervals
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-09) Chandra, Tanvi; Shankhdhar, Deepti
    Wheat (Triticum aestivum L.), a major staple food resource for the world’s population. In present scenario climate changes and elevated temperatures are the big issues that limit its production. An inappropriate timing or delay in sowing is also responsible for sudden elevation in air temperatures during sensitive growth stages of wheat life cycle. Being a winter crop, variability in climates is one of the biggest environmental threats to Indian wheat. The present investigation was carried out to evaluate the effect of elevated temperatures due to variation in sowing timings (November and December) on morpho-physiological and biochemical parameters of 8 varieties of wheat namely; UP2628, HD3086, UP2967, UP2784, UP2526, UP2565, UP2748 and HD3059, conducted during the two consecutive years of Rabi season 2018-19 and 2019-20 in Pantnagar (tarai region). A delay of 30 days in sowing, results elevation in air temperatures; 3.7ºC at tillering, 1.9ºC at heading, 3.7ºC at anthesis and 2.9ºC at grain filling. The morphological, physiological and biochemical parameters, yield and yield related attributes, days taken to complete developmental stages were significantly reduced under December sown wheat varieties as compared to November sown wheat varieties. 3rd internodal distance was found affected by elevated temperatures as compared to 1st and 2nd. On comparing between sensitive growth stages; thermo tolerant traits such as relative water content, membrane stability index, chlorophyll fluorescence, canopy temperatures, chlorophyll pigments and NR activity was significantly decreased during grain filling stage as compared to anthesis. While antioxidants and proline content were found increased as the varieties moves towards grain filling. Quality parameters, carbohydrates, starch and amylopectin were found negatively affected by elevated temperatures while grain nitrogen, storage proteins, amylose content, amylose to amylopectin ratio was positively influenced in December sown wheat varieties. Positive and significant correlation between grain yield and other parameters was found in wheat varieties sown in November while under December sown, relations between the grain yield and other parameters were significantly changed except the correlations among physiological traits, in which non-significant difference was observed between two sowing months.
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    ThesisItemOpen Access
    Evaluation of physiological and biochemical parameters of rice (Oryza sativa L.) genotypes under different nitrogen doses
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2017-07) Chandra, Tanvi; Shankhdhar, Deepti
    Rice is the oldest domesticated grain and serves as a staple food for almost 50% of the world’s population. As the population increases day by day, the demand for food crops also increase. Nitrogen is the key nutrient element limiting the yield of rice. Use of nitrogenous fertilizers by the farmers to enhance yield is the major concern of today because of the excessive use of these fertilizers has led to bad impact on the crops as well as the environment. Nitrogen deficiency in soil is also be problematri. The present investigation was carried out to evaluate the effect of different nitrogen doses (N0, N50 and N100) on physiological and biochemical parameters of 12 genotypes of rice namely RNUE 1 (Vardhan × BPT 5204/6), RNUE 2 (Vardhan × BPT 5204/10), RNUE 3 (Sampada × Jaya/2), RNUE 4 (Sampada × Jaya/3), RNUE 5 (Vardhan ×MTU 1010/2), RNUE 6 (Rasi × Jaya/2), RNUE 7 (Vardhan), RNUE 8 (BPT-5204), RNUE 9 (Sampada), RNUE 10 (Jaya), RNUE 11 (MTU 1010) and RNUE 12 (Rasi) which was conducted during the Kharief season of 2016. On increasing the nitrogen dose, physiological parameters such as, plant height, tiller numbers, LAI, flag leaf length & width, spikelet number & grain number, panicle weight & number, shoot weight, TDM, 1000 grain weight, economic and biological yield were enhanced with increasing nitrogen doses when compared with control. The biochemical parameter such as chlorophyll content, NR activity (in leaves) protein (in seeds) of different genotypes were also found to be increased with increasing concentration of nitrogen. Among all the genotypes maximum economic yield was observed in RNUE 10 (Jaya) under N50 and RNUE 4 (Sampada × Jaya/3) under N100 dose However, RNUE 10 (Jaya) was found to be the most nitrogen use efficient genotype.