| Maize was moderate salt-alkali tolerance crop. Then it was serious yield reduction and even no yield planting in salt-alkali tolerance. The progress of solve the alkali soil problems through soil improvement means etc were slow, however, enhancing salt-alkali tolerance in varieties were urgent needed. But we lack of salt-alkali tolerance germplasm resources of maize, and it was difficult to breeding new salt-alkali tolerance varieties with in the conventional way. Transgenic technology and salinity resistance gene cloning offers an effective way for the cultivation of new varieties of salinity resistance. However, using transgenic technology to import the salinity resistance genes into the maize inbred line to gain new transgenic germplasm must be carried out salinity functional verification. In this study, test materials were conversion of maize offspring strains of BcWRKY1gene transcription factor from the thick leaves rotary capsule pseudochirita, the blue copper protein gene BcBCP1, dehydrin gene BDN1, and the betaine aldehyde dehydrogenase gene from different atriplex the BADH. While optimizing identification system’s salinity resistance in seedling stage, a combination of potted seedling identification and saline pool identification are adopted to identify the function of genetically modified material. And then we filter out the significantly improved salinity resistance maize new line. It brings germplasm resources for the salinity resistance maize breeding of genetically modified and the research of molecular mechanism.And it provide technical support for the industrialization of the genetically modified maize that have the quality of adversity resistance. The main results were summarized as followed:(1)We took32transfer BcWRKYl gene lines,9transfer BcBCPl gene lines,4transfer BDN1gene lines and4transfer BADH gene lines of T1and T2generations and11receptor inbred lines as test materials, Processing maize seeding by using the screened seedling identification concentration (300mmol/L of NaCl solution) in the period of three leaves and a centre. Different classifications are seted by the improved degree of the salt tolerance between genetically modified materials and contrasts, with the difference between the average results of the genetically modified materials indexes assignment and the average results of the control receptors by determination of physiological indicators. Grading standards are:genetically modified maize and the control have the same salt tolerance, salt tolerance have not increased, the difference between the average value and control value x≤0.5; Genetically modified maize salt tolerance improved one grade than the contrast, salt tolerance slightly improved, the difference between the average value and control value0.5<x≤1.2; Genetically modified maize salt tolerance improved two grade than the contrast, salt tolerance significantly improved, the difference between the average value and control value1.2<x≤1.9; Genetically modified maize salt tolerance improved three grade than the contrast, salt tolerance greatly improved, the difference between the average value and control value1.9<x.(2)Salt tolerance evaluation of above49transgenic lines under established evaluation method, screened five transgenic lines whose salt tolerance improved three grades. There contained3transfer BcWRKYl gene lines whose receptor was05-2044were18、20and24lines respectively;2transfer BcBCPlgene lines whose receptor was K10were37and38lines respectively.(3)We took32transfer BcWRKY1gene lines,9transfer BcBCP1gene lines,4transfer BDN1gene lines and6transfer BADH gene lines of T1and T2generations and11receptor inbred lines as test materials, Processing maize seeding by using the screened seedling identification concentration (35mmol/L of Na2CO3solution) in the period of three leaves and a centre. Different classifications are seted by the improved degree of the alkali tolerance between genetically modified materials and contrasts, with the difference between the average results of the genetically modified materials indexes assignment and the average results of the control receptors by determination of physiological indicators. Grading standards are:genetically modified maize and the control have the same alkali tolerance, alkali tolerance have not increased, the difference between the average value and control value x≤0.5; Genetically modified maize salt tolerance improved one grade than the contrast, alkali tolerance slightly improved, the difference between the average value and control value0.5<x≤1.2; Genetically modified maize alkali tolerance improved two grade than the contrast, alkali tolerance significantly improved, the difference between the average value and control value1.2<x≤1.9; Genetically modified maize alkali tolerance improved three grade than the contrast, alkali tolerance greatly improved, the difference between the average value and control value1.9<x.(4)Alkali tolerance evaluation of above49transgenic lines under established evaluation method, screened7transgenic lines were transfer BcWRKY1gene lines whose salt tolerance improved three grades. There contained3receptor was Dong46were4、5and8lines respectively;1receptor was LX9801was12lines respectively;3receptor was05-2044were20、21and24lines respectively.(5)We took8transfer BcWRKYlgene lines,4transfer BcBCPl gene lines,3transfer BDN1gene lines and3transfer BADH gene lines of T3and T4generations and15receptor inbred lines as test materials, yield per plant and biological yield as the evaluation index, screened6new salt-alkali tolerance lines in the highly alkali soil conditions through the whole growth period. There contained4transfer BcWRKY1gene lines whose receptors respectively were444、He344、 LH1037、K10(material number:27,30,52,53);1transfer BcBCPlgene line whose receptor was7884(material number:54);1transfer BDN1gene line whose receptor was Dan598(material number:56). (6)Summarized the results of salt-alkali tolerance evaluation in seedling stage and salinization pool identification in whole growth period of transgenic maize, finally,8high salt-alkali tolerance lines were screened, there contained6transfer BcWRKYlgene lines whose receptors respectively were two05-2044materials(material number:20,24) and444、He344、LH1037、K10(material number:27,30,52,53);1transfer BcBCP1gene line whose receptor was7884(material number:54);1transfer BDN1gene line whose receptor was Dan598(material number:56).(7)We screened8high salt-alkali tolerance lines finally which contained6transfer BcWRXY1gene lines, it illustrated that BcWRKY1gene could significantly improve the salt-alkali tolerance of maize and showed great application potential in cultivating new alt-alkali tolerance varieties. |
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