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Researcher Keerthi, C. M.
Advisor Ramesh, S.
Source KrishiKosh-Indian National Agricultural Research System
Content type Text
Educational Degree Doctor of Philosophy (Ph.D.)
File Format PDF
Language English
Subject Domain (in DDC) Technology ♦ Agriculture & related technologies ♦ Techniques, equipment & materials
Subject Keyword Genetics and Plant Breeding ♦ Inheritance and Characterization of Candidate Genes Controlling Photoperiod-induced Sensitivity To Flowering
Abstract An understanding of the effect of environmental cues, especially photoperiod and temperature on time to flowering, and the genetics of photoperiod-induced sensitivity to flowering time (PSFT), growth habit (GH), floral and pod traits help enhance the pace and efficiency of breeding dolichos bean, a photoperiod sensitive (PS) short-day grain legume species. A series of experiments carried out at the experimental plots of the Department of Genetics and Plant Breeding, University of Agricultural Sciences, Bengaluru during 2012-2015 revealed the greater role of temperature than photoperiod in regulating time to flowering of PS genotypes. Dolichos bean requires critical minimum and maximum photoperiod of 11.11 hrs and 12.28 hrs, respectively for time to flowering. While, PSFT and flower color (FC) are each controlled by biallelic monogenic locus, GH, pod curvature (PC) and raceme emergence (RE) are each controlled by two genes with classical complementary and inhibitory epistasis, respectively. The genes controlling GH, PSFT and RE are linked with recombination fractions and map distances of 0.24 and 33.61cM between PSFT and GH, 0.35 and 61.40cM between PSFT and RE and 0.31 and 49.43cM between GH and RE. Higher amino acid sequence homology of dolichos bean homologues (LpLFY, LpFKF1, LpLHY and LpTFL1) of Arabidopsis PSFT candidate genes (LFY, FKF1 and LHY) and GH candidate gene (TFL1) with those of soybean, common bean and Medicago and cleaved amplified polymorphic sequences assay indicated possible similar genetic and physiological mechanisms controlling PSFT and GH. The results did not favour ignoring epistasis in studies designed for determining the relative magnitude of additive and dominance genetic variances controlling the target traits. The study also revealed preferential use of parents contrasting for general combining ability and/or with intermediate genetic divergence to maximise the frequency of heterotic hybrids, the use of which is likely to result in greater chances of recovering high yielding purelines.
Educational Use Research
Education Level UG and PG
Learning Resource Type Thesis
Publisher Place Bangalore
Size (in Bytes) 4.63 MB
Page Count 233