Analysed And Identified Of Drought Tolerance Mutant 18-599M Offspring

Drought is one of the most important abiotic constraints in maize (Zea mays L.)production. Breeding and extending drought tolerant varieties is the most effectiveand economical method for reducing the loss of drought. Therefore, extendinggermplasm resource, creating germplasm material and especially innovation andutilization of excellent anti-stress material are important in maize breeding. There arelots of methods for enhancing and creating germplasm resources, but physical andchemical mutating and screening mutant is usually used.The calluses of excellent inbred line 18-599 were treated by ⁶⁰Coγ-ray andNaN₃ respectively, and drought tolerant mutations were screened at high osmoticpotential culture of 1.0% NaCl. Drought tolerant mutation is studied in this research.The offspring of mutation inbred line and control were displayed and analyzed withdrought tolerant and main agriculture character. At the same time, through SSRdetection, the differences of drought tolerant mutation and control were alsodisplayed.The drought tolerance of inbred lines of mutant with together wild wasidentified under plastic rain shelter with Anthering and Silking Interval (ASI) and perplant kernel yield as indices. The result showed that the drought tolerance of 18-599Mis significantly stronger than wild 18-599. At Guangxi and Ningxia province, thetolerant ability to water stress of 18-599M was always better and stable than wild.While under normal water condition, there were no significant difference between18-599M and 18-599 about their phenotype and combination ability.In order to study mutant 18-599M in the level of molecule, the differences wereto be found in 7 pair primers that amplified sequence-tagged microsatellites from theirgenomic DNA among 700 pair SSR primers. It indicated that mutant 18-599M isdifferent from wild 18-599 at genome level. The amplified product of primer ph080lying in 8.08 bin have been testified that it is part of glutathione-s-transferases(GST)gene. GST have act in osmosis stress tolerance in some plants. The GST gene were cloned and tested sequence. The result was displayed that the mutant happened in thegene 5'non-code area and the 103th amino acid which changed from Ala to Thr.However, it unknown the relationship between drought tolerance enhancing of18-599M and 5'non-code area mutant. It is important to analyze the relationship inmaize not only for further understanding the drought tolerance mutant but also forunderstanding the molecular mechanisms of maize drought tolerance.