Response of Nerica Rice Genotypes to Varied Soil Moisture Levels and Implications for Drought Tolerance and Grain Yield
DOI:
https://doi.org/10.46881/ajsn.v4i0.81Keywords:
Oryza sativa, O. glaberrima, Vegetative traits, Root traits, HeritabilityAbstract
Drought stress is the most severe abiotic constraint to high grain yield in upland rice and this is typical of the resource limited farmers of the tropics. Sixteen upland rice comprising basically interspecific NERICA varieties were raised in the green house under five different moisture levels and evaluated for vegetative, root and grain yield components with a view to identifying drought tolerant genotypes. Relevant data were collected and analysed to obtain variances and heritability of plant traits and the influence of moisture levels for drought tolerance assessment. There was significant genotype variation for root branching, root thickness and root dry weight. Shoot dry weight and grain yield characters equally exhibited significant variation. Heritability estimates were generally low for all traits, the highest being 30.4 for leaf width. Significant effect of moisture level was also obtained for final height, shoot biomass, leaf width, root length, root branching and root dry weight, panicle number, primary and secondary branching, panicle grain weight and grain weight per plant. NERICAs 7, 12 and 16, however exhibited above average grain production across the moisture levels. Generally, the highest expression of root, vegetative and grain yield traits were diffused among the genotypes. Twenty five percent reduction in moisture requirements resulted in 51.3% and 53.7% reduction in grain production compared to plants raised under full moisture application and rain-fed condition respectively. Differences in vegetative, root and grain yield characters and the influence of varied moisture calls for further intro-gression of superior plant performance traits into a few genotypes for enhanced drought toleranceReferences
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