Selection on the basis of grain yield
for improved performance under excessive moisture stress has often been misleading and considered inefficient. We assessed the importance of secondary traits of adaptive value under waterlogging stress. During the 2000–2004 summer-rainy seasons twelve trials were conducted and a total of 436 tropical/subtropical inbred lines (S
) were evaluated under excessive soil moisture stress. Excessive moisture treatment was applied at V
growth stage by flooding the experimental plots continuously for seven days. Different phenological and physiological parameters were recorded before, during and either immediately or 1–2 weeks after exposure to stress. Excessive moisture conditions significantly affected all the morphological and physiological traits studied. However, there was significant genetic variability for various traits, especially for root porosity and brace root development that were induced under excessive moisture. Across the trials, significant genetic correlations (p<0.01) was obtained between grain yield and different secondary traits, including ears per plant, root porosity, brace root fresh weight, number of nodes with brace roots and anthesis silking interval. Broad-sense heritability decreased under excessive moisture stress conditions for most of the traits; however, it increased significantly for root porosity, nodal root development and ears per plant. Our findings suggest that consideration of these second-ary traits during selection of maize germplasm for excessive moisture tolerance can improve selection efficiency and genetic gains.
AICRP, 2006. Directors’ report, 49
Annual Maize Workshop of All India Coordinated Maize Research Project, held at Birsa Agriculture University, Ranchi, India, 4–6 April 2006.
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Lafitte H.R. Efficiency of secondary traits for improving maize for low-nitrogen target environmentsCrop Sci.19973711101117)| false
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Khera, A.S., Dillon, B.S., Saxena, V.K., Barar, H.S., Malhi, N.S. 1990. Genetic and Physiological Studies in Maize on Tolerance to Stress Caused by Waterlogged Conditions. Ad-hoc project, ICAR, New Delhi, India.
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Malhi N.S. Genetic and Physiological Studies in Maize on Tolerance to Stress Caused by Waterlogged Conditions1990)| false