Screening Salt-tolerant Germplasm And Development Of Functional Markers Related To Salt Stress In Cotton

Cotton isone of stronger crop in salinity tolerance,which is recognized as a pioneer crop in exploitation and utilization of saline-alkali land,Development of planting saline-alkali by application of the biological characteristics of salt tolerance cotton is a effective way to relieve the contradiction between grain and cotton for land and improve the cottonproduction,however,the development of salt tolerant cotton cultivars has been limited.The whole low level of salt tolerance,concentration of basic germplasm and The quite narrow genetic basis of salt tolerance varieties were reasons given for the slow of work...In recent years,for exploreing plant's salt tolerance,RNA-Seq has been used widely at home and abroad,which can rapidly identify gene tags related phenotypes and exploited functional markers.Marker Assisted Selection can effectively improve the efficiency of breeding work.To broaden the genetic basis of upland cotton and improve the choice efficiency of salt resistance cotton,the main research work is as follows:1.In order to broaden the genetic diversity of upland cotton salt resistance,we constructed a BC2F7 population?total 327 lines?derived from?Simian 2×G.klotzschianum?xSimian 2?G.hirsutum?.based on the relative germination rate,13 lines?relative germination rate>49%?were selected with the significant difference by treated with 200mmol NaCl.the Sul2 is used as a salt sensitive control?25.47%?.then to acess the salt tolerance of 13 selected lines,Identification of salt tolerance in salt pond,the degree of cotyledons harm,chlorophyll content,shoot height and root,stem,leaf dry mass are measured for 13 selected lines.The results showed that A2059?A2327 and A2104 are highly salt tolerable,A2130 and A2121 are salt tolerable.2.RNA was extracted from roots&leaves of Miscot7913-83 and Sul2 treated with 200mM NaCl for 12 and 72h.We obtained their information from transcriptomes and DGE using Illumina sequence platform and the de novo method.Unigenes are annotated at NR?NT?KO?SwissProt?PFAM?GO?KOG database,Successful annotated gene number and proportion are as followed as:37,682?52.11%??24,990?34.56%??11,901?16.46%??26,192?36.22%??24,812?34.31%??29,080?40.22%?and 13,549?18.73%?,respectively.There are 3232 DEGs from the same tissue Miscot7913-83 and Sul2 at the same treated time;459 common DGEs is from root;106 common DGEs is from leaf.These common DGEs are annotated at GO and KEGG database,the results showed that antioxidant reactivity,fatty acid and amino sugar metabolism and photosynthesis play an important role responsing to salt stress.3.60 EST-InDel primers and 68 SSR primers are developed based on these DEGs and the usable primers.of them,8?13.3%?InDel primers and 11?16.2%?SSR primers by PAGE.We also measured the relative germination potential and relative germination rate of 96 random upland cottons,which are salt sensitive or tolerance.Correlation analysis of phenotype and genotype were analyzedsbased on the t-test?at p=95%level?,the result showed that 2 markers?Jaas₇058 and InDel₂27?were significantly correlation with relative germination vigor accounting for variation of 9.7%and 5.7%,respectively;anthor 2 markers?Jaas₇058 and InDel₂27?were significantly correlation with relative germination rate accounting for variation of 8.4%and 2.8%,respectively.