Drought Tolerance Assessment And Excavation Of Drought-tolerant Gene During Germination Period In Corchorus Olitorius L.

Planting area and yield of Corchorus olitorius L.were less than those of natural fiber crop cotton.Jute is mainly planted in non-arable land areas in China.Global warming and frequent seasonal droughts are the main environmental factors that it was affected seriously jute growth.It was of great theoretical and practical value to screen the drought-tolerant cultivars and excavate the drought-tolerant genes of jute.In this study,237 jute core germplasm materials were used as research objects.The180g/L,190g/L and 200g/L PEG-6000 were used to simulate the drought environment.Relative germination potential and relative germination rate were selected as two key germination traits index.Cluster Analysis and Membership Function Value Comprehensive Analysis were used to evaluate and identify the drought tolerance to screen drought-tolerant germplasm resources at germination stage of the jute.Meanwhile,Genome-Wide Association Study(GWAS)was used to excavate drought tolerance related genes on their chromosome loci.For further research the genetic information of drought tolerance and molecular breeding of jute was had theoretical foundation.The main results were as follows:1.The drought tolerance of difference jute varieties was significant different.The relative germination potential of jute was more sensitive to drought stress.They had screened 4 high sensitive varieties of BL/093,M112,M113 and M106.2 extremely drought-resistant varieties of Y024 and K-42.These 6 extreme jute varieties had provided basic experimental materials for further research on drought tolerance breeding and molecular mechanism of regulation network system.2.Based on filtered 1,173,491 high-quality Single Nucleotide Polymorphism(SNP)markers,and used the Mixed Linear Model,drought-tolerant traits phenotypes of 237 jute germplasm under 3 different environments had performed by GWAS.A total of 122 significantly associated SNP loci were detected on the-lg(P)=5 threshold line,They mainly located on chromosomes 1,2 and 4,36,36 and 25,respectively,of which 5 number are multi-environmental stable genetic loci.3.It was excavated potential candidate genes based on the information of 122 significantly associated SNP loci,within 100 KB upstream and downstream of genome-wide annotation information.This had received 491 candidate genes functional annotation information which they had about 116 candidate genes distributed on chromosome 1,63 candidate genes distributed on chromosome 2,4candidate genes distributed on chromosome 3,139 candidate genes distributed on chromosome 4,57 candidate genes distributed on chromosome 5,84 candidate genes distributed on chromosome 6,28 candidate genes distributed on chromosome 7.4.According the 491 candidate genes functional annotation information,it had further identified 64 key candidate genes for drought tolerance.The main drought-tolerant gene functions annotated include Sodium-potassium ion channel proteins,N-acetyl-glutamic phosphate oxidoreductase,SAM-methyl transferase,cation channel protein,peroxidase,plant auxin responsive protein,Zinc finger structure,calcium dependent protein kinase(CDPK),amino acid transfer receptor protein,inositol,glutathione transferase and ubiquitin protein;The result had showed that function protein of drought-tolerance gene were various enzyme proteins,transporters,and transcription factors.