|Author:||Olaoye, G. L.|
|Book Group Author:||NA|
The efficiency of soil water utilization under moisture deficit condition can help reduce the adverse effects of drought stress in crops. Growth, physiological responses and grain yield loss due to moisture deficits around flowering were investigated in maize populations derived by reciprocal crosses between 2 adapted maize cultivars (DMR-LSR-Y and AFO) and 2 drought-tolerant (DT) inbred lines (DT-S3-Y and DT-S3-W) under glasshouse conditions. The crosses and their parents and crosses were subjected to irrigation treatments equivalent to 25, 50, 75 and 100% field capacity (FC) as well as water withdrawal for 2 weeks at vegetative, pre- and post-anthesis stages, respectively. Reduction in biomass yield (BMY) under low moisture regimes were within the range of 75-61% of BMY obtained under favourable irrigation treatments, while pre- and post-anthesis moisture deficits also significantly reduced grain yield by 49 and 66% of well-watered condition. Reciprocal crosses between AFO and DT-S3-Y consistently gave highest BMY under irrigation treatment equivalent to 75% FC and above with percent gains ranging from 3.05 to 44.2, respectively. All crosses, except 2 of them (DT-S3-Y × AFO and AFO × DT-S3-W) evidenced superiority for BMY and water use efficiency over their respective better parents under low moisture conditions. Heterotic response for grain yield differed among crosses depending on soil moisture condition. There was no direct association between drought sensitivity index (DSI) and grain yield in the populations, but genotypes with short anthesis-silking-interval (ASI) under moisture deficit conditions showed superiority for grain yield over those with longer ASI. The above results suggested that short ASI when combined with high grain yield under moisture deficit conditions was a better selection tool for identifying drought tolerant genotypes than DSI.
|Pages:||237 - 251|
|Journal:||Tropical and Subtropical Agroecosystems|
crop yield, crosses, crossing, drought resistance,genotypes, growth, heterosis, hybrids, irrigation, maize, plantphysiology, plant water relations, stress, stress factors, stressresponse, water stress, water use efficiency, Zea mays, Zea, Poaceae,Cyperales, monocotyledons, angiosperms, Spermatophyta, plants,eukaryotes, corn, drought tolerance, hybrid vigor, hybrid vigour,outbreeding enhancement, watering, Field Crops (FF005) (New March 2000),Plant Breeding and Genetics (FF020), Plant Water Relations (FF062),Plant Production (FF100), Environmental Tolerance of Plants (FF900),Soil Water Management (Irrigation and Drainage) (JJ800) (Revised June2002) [formerly Soil Water Management]