Abstract:
This research was aimed to adapt some promising
mung bean genotypes to water stress through a field based
screening study which was conducted at the Field Crops
Research and Development Institute, Maha Illupallama.
Three mung bean breeding lines (MIMB 901, MIMB
902 and MIMB 903) and two local varieties namely
MI6 and Ari were grown under three different irrigation
regimes – i.e. full recommended irrigation (no water
stress), half of the recommended irrigation (mild water
stress) and rain fed condition (severe water stress). Water
stress was imposed two weeks after sowing. Treatments
were arranged in a split plot with three replicates with
water regimes in main plots and genotypes as sub plots.
Soil moisture was determined gravimetrically over the
growth period. The maximum leaf area per plant (LA) was
calculated by periodic destructive sampling. Unit leaf
net photosynthetic rate (Pn
) was measured at flowering.
Number of pods per plant (P), seed yield (Y) and harvest
index (HI) were measured at the harvest. The data were
analyzed with SAS 9.1 statistical package through analysis
of variance procedures and least significant differences
(LSD) at 0.05 probability was used for mean separation.
Based on the tolerant characters, MIMB 901 could be
a tolerant genotype under both mild and severe water
stress conditions. MI 6 and MIMB 903 were moderately
tolerant to both water stress conditions. In contrast, ARI
was tolerant under mild water stress while moderately
tolerant to severe water stress. MIMB 902 was identified
as drought susceptible genotype under both water stress
conditions. These tolerant traits could be incorporated
in future crop improvements of mung bean while doing
confirmatory studies in several locations
