Genetic and Morpho physiological characterization of maize Zea mays L for drought tolerance

Abstract

Maize uses moisture effectively to produce dry matter and requires 500 to 800 mm of water. Drought is the major stress among the overall abiotic stresses that harmed maize. The most practical method to deal with drought stress is the development of drought tolerant cultivars. Identifying base population is the first step for breeding drought tolerant cultivars. As a result, efforts are currently being taken with four objectives viz., to screen the maize inbred lines in drought environments in order to choose the best drought-tolerance inbreds to generate hybrids and assess their superiority using combining ability and heterotic potential and to identify widely contrasting drought tolerance related phenotypes suitable for the genetic studies. In first experiment, initially (2021 summer) 51 inbreds were subjected to stress at flowering stage was evaluated under field condition in E1 (Coimbatore). From those screened lines, totally nine tolerant and susceptible lines were evaluated for drought stress in E1 (Coimbatore) and E2 (Vagarai) in next season (2022 summer) to assess their tolerance potential. The results from the study manifest that the traits studied had a significant variation for drought stress and provides scope for the selection of drought tolerant lines. The association analysis reveals that the yield is correlated significantly with all yield related attributes and negatively associated with ASI. The results from PCA, cluster and MGIDI analysis reveals that the inbreds N09-162, 52099 and N10-51 were found to have better drought tolerance and consistent over years and locations. Aside from genotyping and phenotyping quantitative characteristics, root phenotyping has been a key problem for plant breeders in improving crop abiotic stress tolerance. Thus, this experiment quantifies root plasticity, physiological and biochemical adaptation of maize under drought stress was done in both green house and field conditions. Comparing the results from both vegetative stage (V4) and flowering stage (V14) drought