Evaluation Stress Resistance Identification Of Banana Radiation Lines And Genome-wide Identification And Expression Analysis Of DREB Gene Family In Banana

Banana is a typical tropical and subtropical fruit tree,which is vulnerable to abiotic str esses such as drought,salt and cold stresses.In order to improve the resistance of banana an d cultivate high-quality banana varieties(lines),the physiological determination and analysi s of stress resistance of radiation-induced mutant lines obtained in the early stage of the lab oratory were carried out,and the field botanical characters and fruit quality were evaluated comprehensively in order to obtain stress-resistant and high-quality mutant lines.Meanwhil e,genome-wide identification and expression pattern analysis of DREB family,the key tran scription factors of abiotic stress response,were carried out to explore the role of DREB tra nscription factors in abiotic stress in banana.The main experimental results are as follows:(1)The stress resistance physiology of three lines of Fuxuan lines,namely,FX1,F X2 and FX3,under drought,salt and cold stresses was tested.The results showed that FX1 had good comprehensive resistance,and it was under three abiotic stresses:relative water c ontent,ion leakage and water potential.The forced performance was better than that of cont rol banana and other lines.(2)In the field botanical traits,the plant height of FX1 was higher than that of the c ontrol Brazilian banana,and the perimeter of the pseudostem of FX1 was similar to that of Brazilian banana,and botanical traits were excellent.The yield of single plant Fuxuan No.1 reached 33.5 kg,which was higher than that of Brazilian banana(23 kg)and FX2(30 kg),only lower than that of FX3(38.7 kg).The length,Fruit thickness and edible rate of fruit fi nger were higher than those of control Brazilian banana and other lines.The starch content of FX1 was higher than that of Brazilian banana.The sugar content and organic acid content of Fuxuan1 were slightly lower than that of control banana,but the fruit sweetness did not decrease,and the organic acid content beneficial to quality increased.Compared with other radiation-selective lines,the fruit quality of Fuxuan1 was better.(3)Banana DREB genome-wide analysis showed that the DREB transcription facto r family of banana contained 96 members,which could be divided into six groups accordin g to phylogenetic relationship.The number of members varied greatly among the groups.Among them,group A-4(32 member)member and group A-5(27member)had the largest n umber and group A-3(2 member)had the least number.The chromosome location of banan a indicated that the DREB members were unevenly distributed,mainly on chromosomes 10 and chromosomes 4,while the other chromosomes contained relatively few DREB membe rs.Gene structure analysis showed that the DREB family of banana was highly similar.Mot if analysis showed that the DREB family had a specific conservative domain AP2 and its ge ne structure was conservative.Subcellular localization analysis showed that DREB family was mainly expressed in the nucleus.The transcriptome analysis showed that 48 genes in th e DREB family expressed under at least one abiotic stress.(4)qRT-PCR analysis showed that MaDREB87 and MaDREB90 were up-regulated under three stresses.MaDREB58 was up-regulated under drought and salt stress,while Ma DREB13,MaDREB16,MaDREB88,MaDREB91 and MaDREB92 were up-regulated under cold and drought stress.Both MaDREB47 and MaDREB95 genes were down-regulated und er cold stress.The expression patterns of MaDREB12,MaDREB94 and MaDREB95 were d ifferent under drought and salt stress.The expression patterns of MaDREB13,MaDREB16,MaDREB47,MaDREB91,MaDREB88 and MaDREB92 were different under salt stress.Th e expression mode of MaDREB72 was different under drought stress,and the expression m ode of MaDREB92 was different under salt stress.The expression patterns of each gene in t he Fuxuan lines were different,which indicated that the same gene responded differently in different lines.