1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Spectral management for improving hotosynthetic efficiency in polyhouse cultivation of vegetables(Department of Plant Physiology, College of Agriculture, Vellayani, 2016) Anjana J Madhu; Roy StephenItem Characterization and evaluation of herbal and non herbal kunapajala on soil health and crop nutrition(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2019) Kavya, S R; Ushakumari, KItem Micronutrient management for okra [Abelmoschus esculentus (L.) Moench ] under diffrent irrigation methods(Department of Agronomy, College of Horticulture, Vellanikkara, 2019) Arya, P; Anitha, SItem Optimization of soil environment and crop response for magnesium nutrition in ultisol(Department of Soil Science and Agricultural Chemistry College of Horticulture, Vellanikkara, 2019) Soniya, V P; Bhindhu, P SItem Molecular screening of rice genotypes for submergence tolerance(Department of Plant Biotechnology, College of Agriculture, Vellayani, 2018) Aryalekshmi, A S; Veena VighneswaranRice (Oryza sativa L.) is the most important staple food crop that providing food to about half of the population. One of the major constraints in rice cultivation worldwide is submergence stress. This mainly affects flood prone areas like kuttanadu Pokkali as well as low lying paddy fields in Kerala. Sub1 is a major quatitative trait locus (QTL) representing a cluster of three ethylene responsive factor (ERF) genes: Sub1A, Sub1B and Sub1C that confers submergence tolerance to rice genotype. Submergence tolerant rice variety is credited with maintaining energy and alcoholic fermentation which require high levels of carbohydrates. Sub1 locus contain Sub1A, Sub1B and Sub1C, all of which are encode ethylene responsive factor and are up regulated under submergence, but only Sub1A is responsible for the flash flood tolerance. The near isogenic lines generated by the introgression of the Sub1 from FR13A into to susceptible cultivar shows restricted shoot elongation similar to FR13A. Submergence tolerant plants suppress the expression of gene encoding α- amylase and sucrose synthase, which are involved in sucrose metabolism. Sub1 A enhance the expression of genes encoding SLENDER RICE -1 (SLR1) and SLR1 like 1(SLRL1), which are key repressor of gibberellins (GA) signalling in rice; it also negatively regulate s the GA response in order to restrict shoot elongation under submergence. Rice varieties with the Sub1 gene were shown higher survival rate with better yield even after 2 weeks of submergence stress. The advancement of marker assisted selection (MAS) have striking impacts on developing improved Sub1 varieties that can meet the increasing demands of consumers along with population hike. In the present study, two rice genotypes were observed with Sub1 QTL using SSR markers through molecular characterization in order to find out the best submergence tolerant lines. Moreover this finding lays the foundation for further researches with sub 1 QTL for crop improvement.Item Interactive effect of UV radiation and elevated temperature on rice growth and physiology(Department of Plant Physiology, College of Horticulture, Vellanikkara, 2018) Amjath, T; Girija, TRice is a staple food for more than half the world’s population. The growth and productivity of the crop is intimately associated with climatic variants. Among different climatic factors, temperature and incidence of UV-B radiation are important. The incidence of stress (Temperature and UV) at different stages of growth determines the productivity of the crop. Hence the present study was undertaken with the prime objective of evaluating the interactive effect of UV-B radiation and elevated temperature at different phenophases of Uma rice variety and its effect on growth and productivity. The study was carried out at College of Horticulture, Vellanikkara during Jan to May- 2018. The UV-B radiation and atmospheric temperature were maximum during this season. 14 days old Uma seedlings were used as plantingmaterial. It was grown under four different conditions, namely T1(10C lesser than ambient+ low UV-B), T2 (10 C higher than ambient+ low UV-B), T3 (20 C higher than ambient+ low UV-B), T4 (Open condition). The plants were kept in the polyhouses for 30 days during three phenophases of the crop viz, seedling to active tillering (P1), active tillering to early reproductive (P2) and early reproductive to harvest (P2) and returned to ambient condition to complete their life cycle. Morphological, biochemical, physiological and yield parameters were analyzed during the growth period. Exposure of plants to T1 (10 C below ambient) had least negative influence on growth, physiology and yield of the crop across different developmental stages. A 10C increase in temperature above ambient (T2) in phase 1 improved the yield and yield parameter. However the impact was negative under same condition during phase 2 (P2) and phase 3 (P3). Maximum deleterious effects were observed in T3 during phase 2 and 3. Plants grown in open condition had lower plant height and higher number of tillers as compared to plants grown in polyhouse condition (T1, T2 and T3). Number of days to heading was less in plants grown under high temperature conditions (T2 and T3). The photosynthetic rate, stomatal conductance and transpiration rate were maximum in T2 condition in all the three phases of growth. Analysis of biochemical parameters showed that the IAA content was 67 percent lesser in plants grown under open condition as compared to ployhouses during P1. Similar decrease was also found in the case of gibberellic acid and chlorophyll. Amylose content of the grain were significantly reduced in the plants grown under T2 and T3 conditions during P2 and P3. Plants exposed to temperature above ambient level (T2 and T3) during P2 and P3 stages recorded a reduction in yield. Maximum yield reduction was observed in T3 condition which was 13 percent in P2 and 56 percent in P3. Reduction in spikelets number and pollen viability were the main reasons. The study indicates that plants were most sensitive to high temperature stress during the P2 and P3 stages, which can contribute to drastic yield decline while, the early stress can have a positive influence on yield.Item Physiological and biochemical studies on growth, development and yield of ginger (Zingiber officinale rosc.)as influlenced by bioinoculants and phosphorus fertilization(Department of Plant Physiology, College of Agriculture, Vellayani, 2018) Amritha Lekshmi, M G; Viji, M MItem Response of bhindi (abelmoschus esculentus L. moench) to fertigation and foliar nutrition in red loam soil of Kasaragod(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Padannakkad, 2018) Ashwini, B N; Binitha, N KItem Standardisation of spacing and nutrient levels for fodder rice bean [Vigna umbellata (Thunb.)].(Department of Agronomy, College of Agriculture, Vellayani, 2018) Ajmal Fayique, C; Usha C ThomasItem Comparative assessment of whole plant water use efficiency (wue) of coconut seedlings (cocos nucifera) to drought tolerance(Academy of Climate Change Education and Research Vellanikkara, 2017) Athul Boby, C; Hebbar, K B