Division of Genetics, Indian Agricultural Research Institute, New Delhi-1100 012
Online published on 25 January, 2012.
Six parents of G. barbadense representing wide geographical divergence and their 15 possible crosses in F, generation were grown under randomised block design with three replications under Coimbatore conditions during winter 1973. Each plot had one row of 4⋅5 meters long with 15 plants per plot. The row to row and plant to plant distances were 75 cm and 30 cm respectively. Observations on single plant for yield, number of bolls and boll weight were recorded. Data were subjected to statistical analysis and heterosis in percentage superiority over mid parent and better parent was calculated.
Two crosses viz. Pima S-4 × E.R.B. 4492 and S.I.V. 135 × E.R.B. 4492 respectively exhibited 111 and 106 per cent heterosis in yield over the better yielding parent. Heterosis in yield in the first cross was found to be made up of heterosis in boll number and boll weight while in the other cross it was mainly due to heterosis in boll number alone.
It is concluded that producing hybrids from crosses between highly divergent parents within the same species with a high degree of heterosis is preferable to interspecific hybrids, because of better fibre quality and low degree of motes and nappiness in the former than the latter.
