Evaluation of advanced generations of sesame (sesamum indicum l.), mutant lines at selected sites in western Kenya
Abstract
Sesame is an important oil crop that is well suited for the marginal areas whose
potential has not been fully exploited in Kenya. A mutation breeding experiment was
initiated at Kabete in the 1990' s to enhance the genetic variability of the crop from
which desirable cultivars could be identified. Several desirable mutant lines now in
advanced generations have been developed. This study was carried out to evaluate
the adaptability of advanced generations of some of these selected sesame mutant
lines at two sites (Siaya Farmers Training Center and Maseno University) in western
Kenya. The objectives were to study the performance of advanced mutant lines and
identify the most promising ones for cultivation in western Kenya.
Thirty mutant lines and four checks were grown in three replicates for two seasons
using a completely randomized block design. Each of the cultivars was sown in three
rows spaced 50 em apart with inter-plant spacing of 10 ern. The seedlings were
thinned at 10-15 em height.
Data on several agronomical traits were recorded during crop growth period. Mean
performance showed that mutant line Mun 096/1/k5/2/4 had the highest performance
as far as yield and yield components were concerned. Variations among the studied
genotypes were also noted, with highest variation coming from seed yield per plant.
The data were also subjected to analysis of variance for each environment for all the
traits as well as across the environments to assess the genotype by environment
interactions. The effects of environment, genotype and genotype by environment
interactions were highly significant for all traits studied. Variations due to genotype
by environment interactions were greater than those due to genotypic differences for
all traits except 1000-seed weight. Genotype x sites x seasons contributed most to the
genotype by environment interactions for all traits except for number of days to
flowering, biomass yield and harvest index. The highest yielding and best-adapted
mutant line was Mun 096/11k5/2/4 followed by MUll 50/1/121 although its yield was
not significantly different from the best check cultivar Spssikl16. These two mutant
lines are therefore recommended for further tests in western Kenya.
With regard to analysis of correlations, gram yield showed a high positive and
significant correlation between grain yield and biomass yield, harvest index and 1000-
seed weight. Seed yield also showed a moderate positive association with plant
height, number of capsules per plant and percent oil content. Path analysis revealed
that biomass yield and harvest index were the major contributors toward the seed
yield.
Citation
Master of Science in Plant BreedingPublisher
University of Nairobi Department of Crop Science