TY  - BOOK
AU  - Mydin K K
AU  - Gireesh T
TI  - Diversity and heterosis by recombination breeding of Hevea brasiliensis in India
PY  - 2016///
PB  - Rubber Science
KW  - Genetic divergence
KW  - Heritability
KW  - Heterosis
KW  - Recombination breeding
KW  - Yield components
N2  - In a recombination breeding programme, 52 hybrids evolved from three cross combinations of Hevea clones were evaluated along with parents for yield and its componets under small scale evaluation in Central Kerala, India over six years of tapping. The components of variation and genetic distances among the progeny and parents were estimated based on analysis of 23 attributes. Rubber yield was reiterated as a highly heritable trait. Parent clones RRII 105 and RRII 118 proved to be genetically very divergent and a high recovery of eight heterotic hybrids was obtained from the progeny of this biparental cross. The pedigree of parent clones was found to contribute to diversity and heterosis. Clonal selection based on yield, girth, yield components and secondary triats led to the identification of eight promising hybrids that exhibited heterobeltiosis for yield to the tune of 43-65 per cent. These were clones 95/323, 95/297, 95/348, 95/351, 95/353, 95/362, 95/442 and 95/448, of which seven were of the parentage RRII 105 X RRII 118. High yielding clones with potential to perform well under drought situations were identified based on yield and its components in the stress period. The low incidence of tapping panel dryness and pink disease in clones 95/297, 95/442 and 95/448 and the steadily increasing trend in yield of 95/448 deserve special mention. The results of this study indicate further scope for exploitation of heterosis in crosses between parent clones with Malaysian and Sri Lankan lineage
ER  -