Quantitative Genetics of Drought Resistance in Early Maturing Maize (Zea mays L.).

Quantitative genetics of drought resistance in early maturing maize (Zea mays L.)

S. Sharma, and M. J. Carena*

Dept. of Plant Sciences, North Dakota State Univ. (NDSU), Dep. #7670, Fargo, ND 58108-6050

*Corresponding author, email: marcelo.carena@ndsu.edu

Abstract

Phenotyping bottleneck is a major challenge in improvement of abiotic stress resistance.  Effective phentotyping of new constitutive traits and their interaction could be useful to accurately identify genetic diversity for abiotic stress resistance and move maize to marginal areas with drought stress and short growing seasons. A short season representative early maturing maize population with forty-seven diverse inbred lines from public and private sources was crossed in a partial diallel mating design. 94 partial diallel crosses with six different commercial top checks were tested in 6 environments in irrigated, non-irrigated and random drought conditions of North Dakota and Montana.  45% and 27% reduction in mean grain yield in drought condition and random drought conditions respectively was observed compared to the well-irrigated condition. The change in rank was significant at 0.05 level of significance across different moisture regime showing importance of developing cultivars for each environment separately. The results showed that the new constitutive traits brace root counts, brace root spread width, stalk diameter and root lodging can be a useful traits for adapting lines to short season drought tolerance. The traits are also useful to increase the genetic diversity of terminal drought resistance.