| Acer truncatum Bunge is an important woody oil tree species in China.It has attracted increased attention because its kernel oil contains a very-long chain monounsaturated fatty acid-nervonic acid.To establish a high-yield,stable-yield,high-quality and high-efficiency oil-type breeding system,this paper investigated and collected the germplasm resources of 11 natural excellent A.truncatum strains in Inner Mongolia,Liaoning,Xinjiang and Shaanxi provinces(or autonomous regions).Based on this,the fatty acid content of the oil-type superior plant seeds at different development stages in Shaanxi Yangling was further determined,and the correlation between the fatty acid components in the oil was analyzed.The SSR loci related to nerovnic acid accumulation were screened by combining genomic and transcriptome data,and SSR markers were developed.The precise study findings are as follows:(1)According to the content of nervonic acid,the 11-region-of A.truncatum germplasms were divided into high,medium,and low nervonic acid germplasms.Among them,there were three germplasms with high nervonic acid content of more than 7.5%,which were Liaoning Jianping(LJP),Inner Mongolia Chifeng(NCF)and Liaoning Fuxin(LFX).6 germplasms with6%～7.5% of nervonic acid content were medium nervonic acid germplasms,including germplasm from Wengniute Banner of Inner Mongolia(NWN),Wudantala Forest Farm of Inner Mongolia(NWD),Fufeng of Shaanxi(SFF),Kazuo of Liaoning(LKZ),Zhangwu of Liaoning(LZW)and Horqin Right-wing Middle Banner of Inner Mongolia(NYZ).There were2 germplasms with low nervonic acid content less than 6%,including Shaanxi Yangling A.truncatum germplasm(SYL)and Xinjiang Kashgar germplasm(XKS).In addition,correlation analysis showed that the accumulation of nervonic acid was significantly correlated with various fatty acids,which was significantly positively correlated with erucic acid and arachidonic acid.In addition,it was also significantly correlated with oleic acid,linoleic acid,α-linolenic acid,arachidonic acid and arachidonic acid.(2)Through the analysis of the genomic SSR loci of the oil-type superior strains of A.truncatum in Shaanxi Yangling,it was shown that the SSR microsatellite loci in the A.truncatum genome had a unique AT codon preference,and the SSR markers were very rich.There were 103,699 highly polymorphic markers and 88,943 potential polymorphic markers.(3)Transcriptome analysis identified 10 fatty acid de novo synthesis key enzyme genes,17 fatty acid elongation related enzyme coding genes,4 fatty acid desaturase coding genes,6triacylglycerol(TAG)synthesis related enzyme genes and 12 fatty acid synthesis and assembly related important transcription factors.25 genes and transcription factors related to nervonic acid synthesis were screened,are respectively FATA＿Ace0157910.1、LACS＿Ace0091930.1、LACS＿Ace0117350.1、LACS＿Ace0050030.1、LACS＿Ace0260820.1、LACS＿Ace0141860.1、KCS＿Ace0090450.1、KCS＿Ace0253040.1、KCS＿Ace0118450.1、KCS＿Ace0090510.1、KCS＿Ace0090490.1、KCS＿Ace0094550.1 、KCS＿Ace0133430.1、KCS＿Ace0148540.1、KCR＿Ace0218780.1、HCD＿Ace0057730.1、HCD＿Ace0070370.1、ABI3＿Ace0112730.1、LEC1＿Ace0030680.1、LEC1＿Ace0180140.1、LEC1＿Ace0142490.1、WRI1＿Ace0242120.1、VAL1＿Ace0163960.1、VAL1＿Ace0213010.1 and VAL2＿Ace0209280.1.Using these key genes,34 SSR molecular markers related to nervonic acid content were developed,and 23 pairs of primers were designed for subsequent verification of polymorphic primers and evaluation of genetic diversity of A.truncatum.In summary,erucic acid,a component significantly positively correlated with nervonic acid,was excavated from the perspective of space and time.At the same time,the change rule of fatty acid was found from the perspective of time.Tne oleic acid and linoleic acid were the main fatty acids,and the change trend were opposite.The content of oleic acid decreased gradually,and the content of linoleic acid increased gradually.The change trend of nervonic acid and erucic acid content were consistent,130-160 DAP increased significantly;in addition,palmitoleic acid,stearic acid,linolenic acid,arachidic acid,eicosadienoic acid,eicosapentaenoic acid and lignoceric acid increased gradually,and myristic acid,palmitic acid and arachidonic acid decreased gradually.Using genomic data and transcriptome data,it was found that A.truncatum SSR had AT preference,and a large number of polymorphic markers were predicted.At the same time,78 sites of fatty acid synthesis were identified,and 34 sites related to the biosynthesis of nervonic acid were screened and the corresponding primers were designed,which laid a foundation for the subsequent primer polymorphism verification and the development of EST-SSR molecular markers for nervonic acid content. |
PDF Full Text Request