Evaluation For Salt-tolerance And Related Gene Analysis In Wheat Landrace

Salinization of soil is one of the major abiotic-stresses that influence agricultural productionand environment. With the increasing of world's population and the decreasing of field, how todevelop and utilize salinized-soil becomes an urgent problem in agriculture production andecological environmental protection. To increase food production for the need of populationgrowing and maintain sustainable development of agriculture, one of the most economic andefficiency strategies to improve and utilize salinized-soil is screening salt-tolerant germplasmresources, discovering and cloning the genes related to salt-tolerance, and breeding new varietiestolerant to salt-stress using biotechniques.102 accessions of wheat landrace groups were studied on the salt-tolerant evaluation, andthe groups which salt-tolerance evaluation results were middle class were selected to study thesalt-tolerance genotypes. Meanwhile, the salt-tolerance related gene were separated and clonedthrough RT-PCR, and the prokaryotic expression system was used to express the target protein.The aim of this study is to provide the theoretical supports and applicable guidances for theutilizations of salt-tolerance wheat germplasm.The study has got following results:1. 102 wheat landrace groups were studied on the salt-tolerance evaluation. 22 groups whichhad middle class evaluation result of salt-tolerance were screened for the analysis of thesalt-tolerance related genotypes. The results of the morphological index analysis of salt-treatedwheat showed that, in the germination stage, the length of relative coleoptile was significantlynegative correlated with the salt injury index; and in seeding stage, the length of relative root andthe ratio of root and shoot after salt treatment were significantly negative correlated with the saltinjury index. The salt tolerance in the germination and seeding stages was different and thecorrelation coefficient was low.2. The genetic diversity of NO.36 wheat landrace group was evaluated. 26 alleles werefound in total, with each SSR locus variation ranging from 2 to 3, and the average allelevariations of each primer was 2.36. The PIC of each primer ranged from 0.071 to 0.512, and theaverage was 0.26. It could be concluded that the variation between the individuals in the samegroup was very small. A broadly varied molecular marker should be needed to analyze thegenotype related to salt-tolerance.3. Salt-tolerance related genes were collected and the primers were designed by the bioinformatics methods. A primer which designed by DREB was screened, and 22 groups whichhad middle class salt-tolerace evaluation results were analyzed for the genotypes related tosalt-tolerance. There were 18 genotypes and 17 SNP loci which included 12 transitions, 3transversions, 1 insert and lindel in 22 wheat landrace groups. The salt-tolerance of crops was acomplex multigene-controlled quantity trait. The SNPs of DREB genes could not describe the salttolerance of wheat completely.4. The RT-PCR technique was used to clone the coding region of DREB in salt-treatedwheat. The cloned fragment was 99ï¼…homologous with the published DREB gene. Theprokaryotic expression vector was constructed successfully and the target protein was expressedthrough the inducement of IPTG. The next researth is to study the transgene of DREB in plant,especially in wheat, and discuss the feasibility of the cultivation of high quality and salt-toleranttransgenic wheat.