The effects of drought stress on cell membrane damage and kernel yield in three maize (Zea mays L.) cultivars

Biological membranes are the first target of abiotic stresses, thus maintenance of their integrity and structure plays a crucial role in drought tolerance of the plants. An experiment was conducted to the split plots based on randomized complete block design with four replications at Zanjan Agricultural College in 2009. The experiment intended to evaluate the cell membrane damages percentage in three maize (Zea mays L.) cultivars based on drought and high temperature methods and determine their relationships to kernel yield. The levels of irrigations (control, drought stress imposed from silk stage and drought stress imposed from dough stage) were set in main plots, and cultivars (SC704, 647 and 500) were set in subplots. The results of this experiment showed significant difference among cultivars cell membrane damage of at all measurement stages (30 days after sowing, silk and kernel dough). The most genotypic differences; however, by considering the cell membrane damage occurred among cultivars after 30 days of sowing. SC500 showed the most unstable cell membrane during kernel dough stage and 30 days after sowing, but SC647 had the most unstable cell membrane in silk stage. The maximum negative correlation was shown between kernel yield and cell membrane damage in all cultivars 30 days after sowing. By considering the cell membrane damage in high temperature method, SC704 and SC500 showed to be the most unstable in silk and dough stages, respectively. Thus, it seems that genotypes screening based on cell membrane damage provides an appropriate criterion for drought stress tolerance.