Abstract:
This study was carried out to assess the performance of advanced common bean lines
(BC 2 F 6 ) to diseases (Angular leaf spot, Common bean blight and Bean common mosaic
virus/Bean common mosaic necrosis virus) and yield and yield components in three
different locations; Arusha, Mbeya and Morogoro. The experiment was arranged in split
plot, main plots were locations (Arusha, Morogoro and Mbeya) and sub-plots were 32
genotypes (28 lines and 4 checks). The results from the experiment revealed high
significant differences (p < 0.05) among genotypes and Genotypes x Environment
interaction in days to 85 % maturity, pods per plant, seeds per pod, weight of seeds per
plant, 100 seed weight and grain yield. There were no significant differences in diseases
(Angular leaf spot and Common bean blight) scores and few genotypes had the Bean
common mosaic virus/Bean common mosaic necrosis virus symptoms basing on the score
of presence and absence. Among the lines that performed well basing on both diseases
and yield were KT 13-1b, KT 4g-3c, KT 6-2d, KT 6-2c, KT 10-2d, KT 11-1a, KT 15a,
KT 9-2b, KT 11-2d and KT 2b. Grain yield had a positive significant correlation with
days to 50 % flowering, days to 85 % maturity, pods per plant, seeds per pod, weight of
seeds per plant, 100 seed weight. This suggests that the traits have to be considered when
breeding for higher grain yield. This study showed that the introgression of genes for
resistance to the three diseases to preferred bean variety Kablanketi was successful since
most of the lines were resistant to the diseases. However, this study needs to be repeated
to verify the performance of these promising lines and planting should be done at the
beginning of the season to ensure that there are favourable environments for diseases
progress.
