TY - BOOK AU - Veena Vighneswaran AU - Kumaran K (Guide) TI - Exploitation of Male Sterility in Sesame (Sesamum Indicum L.) U1 - 630.28 PY - 2001/// CY - Vellanikkara PB - Department of Plant Breeding and Genetics, College of Agriculture N2 - The research project "Exploitation of male sterility in sesame (S.indiclll1l L.)" was carried out in the college of Horticulture, Kerala Agricultural -University, Vellanikkara during 1996-'99. The persent investigation was carried out with a view to assess the variability and to estimate 'the combining ability of selected lines. Exploitation of male sterility in sesame through induced mutagenesis and wide hybridization for future development of hybrid sesame was also aimed at. Sixty genotypes of diverse origin were evaluated during '96-'99 at Onattukara Regional Agricultural Research Station, Kayamkulam for their divergence using Mahalanobis D2 statistics. Based on yield and attributed components, these genotypes were grouped into eight clusters. Eight genotypes representing each cluster were selected and were evaluated for their combining ability, gene acton and heterosis using diallel analysis. Two best general combiners were selected and carried forward for the induction of male sterility through mutagenesis and wide hybridization. The wide range of variation was noticed in all the ten characters among the 60 genotypes selected for divergence study indicates the presence of substantial genetic _ variability among the genotypes. The magnitude of heterosis was largely dependent on the degree of genetic diversity in the parental lines. The study on genetic parameters revealed that the characters number of branches per plant, number of capsules per main stem and seed yield per plant exhibited high broad sense heritability coupled with high expected genetic advance along with high or moderate GCV. Correlation studies revealed that the principal yield determining components were capsules per main stem and capsules per plant. While selecting genotypes for higher yield potential, emphasis should be given for these characters. Cluster analysis revealed that there was no parallelism between geographical distribution and genetic diversity of the genotypes. The sixty genotypes representing different geographical regions were grouped into eight clusters based on genetic distances. Combining ability studies revealed the importance of all the three additive, non-additive and maternal effects in all the characters studied. The varieties Thilak and OS-2 were identified as best general combiners. Studies on induced mutagenesis clearly indicated that both physical as well as chemical mutagens reduced the germination, survival and fertility in the M] population. A linear increase in the sterility with increase in the doses of mutagens was noted. Chemical mutagens were found to induce more number of steriles than the physical mutagens. Male sterile types isolated were similar in habit as the normal plants but for their shrunken, green undersized anthers. These plants had normal female fertility and exihibited regular seed set. Inheritance studies indicated that the present case of male sterility is governed by a single recessive gene. In the wide hybridization of Sesamum in dicum x S.malabaricum, F I S had high percentage of pollen fertility as indicated by a fairly good capsule set on selfing while reciprocals had little capsule set on selfing. This points to a positive role of the wild cytoplasm on the expression of sterility in crosses where S. malabaricum was used as female parent. The F I interspecific hybrids both direct and reciprocal, exihibited dominance of the wild parent characters in hybrids. Progenies of back crosses BCI and BC2 exihibited more of the attributes of the recurrent parent indicating further improvement of hybrids for desirable attributes retaining high levels of male sterility along with. These lines offer scope for efficient utilization in future hybrid seed production programme in cultivated sesame. UR - http://krishikosh.egranth.ac.in/handle/1/5810015080 ER -