POSSIBILITY OF COMMERCIAL UTILIZATION OF RESIDUAL HETEROSIS IN KENAF (HIBISCUS CANNABINUS L.)

Abstract

Combining ability and heterosis were studied in line x tester crosses between 24 female and 4 male parents for fibre yield in kenaf. The gca and sca variances showed that gene action was predominantly additive. The accessions, CPI-072111 and CPI- 78891 and the variety AMC-108 were good general combiners. None of the crosses showed significant positive sca effect for fibre yield. But eight crosses showed 30-40% heterosis over popular variety HC-583. In absence of male sterile line in kenaf, mannual production of hybrid seed and subsequent exploitation of heterosis becomes prohibitive due to high cost of Fl seed production. Hence an attempt was made to study the extent of residual heterosis present in F2 due to predominance of additive genes so that F2 seeds may be utilized to get heterotic effect with lower cost of seed production as has been done in other crops. Fibre yield performance of two generations (Fl and F2) of selected cross combinations and two standard check varieties (HC- 583 and AMC-108) were studied and decline in yield from Fl and F2 was observed. Results showed that three crosses each between one exotic germplasm and one indigenous variety retained substantial amount of residual heterosis in F2 generation that may be exploited and utilized commercially with lower cost of seed production.