Studies On Inheritance Of Drought Tolerance And Creating Of Drought Tolerant Material In Maize

Drought is one of significant factors that restrict the production of foodstuff. According to the statistics of the State Information Center, there are more than 27 million ha plowland that have been bearing drought every year in china from 1950 year to today, and cutting harvest production was more than 100 hundred million kilogram, accounting for 60% of sum of many natural disasters. There are 20000 thousand ha areas that plant maize in our country, accounting for one third of sum of crops planting areas, and among that there are two third maize planted in dryland. Losing yield average were about 15% due to drought, only inferior to harm of plant diseases and insect pests. Maize needs much of water to complete its life, and it is very sensitive to short of moisture than other kinds of crops. Therefore, studying about inheritance of drought tolerance in maize is very important to understand drought tolerant mechanisms, find drought tolerant genes, and improve maize-self drought tolerance, breed drought tolerant varieties that can tolerate drought and get stable yield in stress of water deficiency.This trial identified and valued drought tolerance of 57 maize inbred lines that have been popularizing in China or breeding newly in recent years, with taking of control water irrigation according to soil moisture condition that was little higher than maize wilting coefficient in sandy loam soil. Then, the strong and sensitive drought tolerant germplasm, and drought tolerant indexes were selected. Based on these results, the gene effects and hereditary models of drought tolerance in maize were studied. The expressional differences of mRNA and proteins were displayed and analyzed with strong drought tolerance inbred line. In order to improving drought tolerance of excellent inbred line and gaining mutant material used to study on inheritance of drought tolerance, the embryonic calluses of excellent inbred line were mutated and screened with physical and chemical mutating method. The main results showed as follows.1. The 57 maize inbred lines were sown in a plastic roof to prevent rainfall. Under soil moisture was controlled at little higher than wilting coefficient (soil absolute moisture is 10%-12%),the drought tolerance of these materials was identified with drought tolerant coefficients of grain yield as indexes. Variational range of drought tolerant coefficients is from 0.810 to 0.048, and drought tolerance of inbred line "81565" belonged to the strongest...