Genetic Analysis of Maize Response to Salt Stress in Hydroponic Medium

Abstract

The productivity of maize (Zea mays L.) from the farmers’ fields has been characterized as being low due to salinity among other contributing factors. In this study the use of phenotypic traits as a selection criterion and screening of maize genotypes for tolerance to salt stress was investigated. The objectives of this study were therefore to i) estimate heritability for genotypic response to root and shoot length ii) ascertain an appropriate genotypic maize screening criterion in saline medium and iii) identify tolerant maize genotypes in hydroponic medium. The experiment was set up as 5 x 11 factorial completely randomized design (CRD) with three replications at the University of Zambia, pathology laboratory. Thus 11 genotypes were evaluated in five doses of salinity concentrations giving 55 experimental units. Genotypes exhibited significant differences (P< 0.05) in response to both parameters (root and shoot length) across salinity concentrations. Similarly the response of root and shoot length in different salinity concentration across genotypes was also significant (P< 0.001). The entry based heritability estimate was found to be 0.76 and 0.18 for responses to root and shoot respectively. Shoot length was identified as a key trait to utilize in screening maize genotypes for tolerance to salt stress under hydroponic conditions despite possessing a low heritability estimate. In this study tolerant genotypes to salt stress were identified as ZHYB 2, ZHYB 7 and ZHYB 11.