Evaluation of physio-biochemical criteria in maize inbred lines and their F1 hybrids grown under water-deficit conditions

Abstract

Since the application of deficit water became a dominant tactic in crop irrigation, developing and surveying newly adapted genotypes should be adopted. In this study, we determined the physio-biochemical activities of 21 maizegenotypesunder 100%and70%cropevapotranspirationirrigation conditions (normaland deficit irrigation, respectively) in sandy soil to determine which activities can identify drought-tolerant, high-yield genotypes. The experimental design was arranged in randomized complete blocks with three replicates. Results showedthatthedrought-tolerant parentsandhybridshadthehighestrelative watercontent(RWC),membrane stability index (MSI), chlorophyll a and b (Chl. a, b), total chlorophyll (total Chl.), chlorophyll a/b ratio (Chl. a/b), chlorophyll stability index (CSI), proline, phenolic content, superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) levels. They also had the lowest malondialdehyde (MDA) content. The physio-biochemical traits werepositively correlated with more tolerant inbred lines and hybrids that displayed a high yield under both irrigation treatments. Furthermore, maize parents that performed well under the 100 % and 70 % evapotranspiration levels were capable of producing high-performance hybrids underbothconditions. Accordingly,the hybrids P1 xP6, P2 x P5,and P4 x P6 gave a highperformance in sandy soil under both conditions, based on yield attributesestimation. Itcouldbeconcludedthatphysio-biochemicaltraitscanbeusedaseffectiveselectioncriteriaat the silking stage of maize plants to identify high-yield inbred lines and hybrids under stress and normal conditions. These findings will undoubtedly aid maize breeders in rapidly improving and developing new droughttolerant varieties.