TY  - BOOK
AU  - Das G
AU  - Kumar S
AU  - Mydin K.K
TI  - Identification of prepotent female parent clones from half-sib progeny analysis of Hevea brasiliensis at early stage-An alternate approach to hybridization under sub-Himalayan West Bengal
PY  - 2019///
PB  - Rubber Science
KW  - Half-sibs
KW  - Juvenile yield
KW  - North-East India
KW  - Polycross breeding
KW  - Prepotency
KW  - Wild Amazonian accession
N2  - Seven promising clones, screened on the basis of their performance over 12 to 15 years under the cold prone agro-climate of sub_Himalayan West Bengal, were evaluated as parents in polycross breeding by evaluation of their open pollinated half-sib progenies. Weight of seeds of RRII 429 was significantly higher than that of RRIM 600 while that of SCATC 88/13 was at par with RRIM 600. Viability of seeds from RRIM 600 and RRII 429 was above 95 per cent, while viability of SCATC 88/13 seeds was low. Among the half-sib progenies of the seven promising clones, performance of progenies of SCATC 88/13 was the best in terms of mean juvenile yield and yield efficiency, despite its low seed weight and viability. Moreover, supremacy of this clone was also evident while selecting half-sib progenies showing above average yield as well in the final screening process. Out of the 28 progenies from different mother clones showing yield efficiency >0.3 g t-1 t-1 cm-1 girth, 21 progenies belonged to SCATC 88/13 indicating prepotency of this parent clone of Chinese origin. This was the first time a wild Amazonian accessions (RO 5363) was used in polycross breeding and the half-sibs produced by this clone had the second largest number of juvenile high yielders after SCATC 88/13. These clones generated more number of superior progenies than Class 1 clones RRIM 600 and RRII 208. For further cloning and evaluation of potential genotypes for the agro-climate of sub-Himalayan India, 34 selected progenies (40;of the top yielders) would be conserved in source-bush nursery. The results also suggest that clones SCATC 88/13 and RO 5363 may be good female parents for further hybridization programs in cold prone regions
ER  -