RESEARCH ARTICLE

Journal of Oil Palm Research Vol. 8 No. 2, December 1996, p. 55-63

THE GENETIC IMPROVEMENT OF THE DELI DURA BREEDING POPULATION OF THE OIL PALM Elaeis guineensis JACQ.

OKWUAGWU, C. O.*

ABSTRACT

The Deli dura breeding population of Elaeis guineensis has a restricted genetic base, with limited heritable genetic variation for the improvement of bunch yield and its two components, mean annual bunch number and single bunch weight. The introgression among Deli sub-populations as a means of improving heritability is here investigated.

Analysis of variance with the estimates of the expectation of mean squares was carried out on three populations: intra-Deli, inter-Deli and inter-dura. Estimates of total and heritable genetic variance (VG and h2 respectively) for total bunch yield and the two components were obtained for the three populations.

Over a four-year period total yield was highest in the inter-dura population (80.3 kg/palm/year) and least in the inter-Deli population (42.4 kg/palm/year). VG was absent for total yield and its two components in the intra-Deli population, but highly significant for all three traits in the inter-Deli and inter-dura populations. For average bunch number h2 was highly significant and accounted for most of the genetic variation for these two populations. Similarly, for single bunch weight in the inter-dura population, h2 accounted significantly for the VG. In the inter-Deli population h2 and non heritable genetic variation significantly determined the average bunch weight. The total yield of fresh fruit bunches was determined mainly by non heritable genetic variation in the inter-Deli population, while heritable genetic variance was high and significant in the inter-dura population.

The continual exploitation of the Delis in the various breeding programmes will not result in genetic improvement for bunch yield. Future progress must rely on the creation of new high yielding populations with a broad genetic base for which heritability for total yield can become significant, as is the case with the inter-dura population evaluated in this study.

KEYWORDS:


* Plant Breeding Division,
NIFOR, PMB 1030, Benin, Nigeria.