Fine Mapping Of Leaf Angle Gene In Tomato

Plant type is an important factor affecting plant yield,and leaf angle is an important part of tomato plant type.Leaf angle refers to the acute angle of the leaf and the main stem,which affects both the photosynthetic efficiency and planting density.As an important trait of plant variety selection,cultivation research and production practice,it has rarely been discussed in the topic of tomato.The development of the leaf angle is influenced by genetic factors,plant hormones and the environment.Through genetic analysis and fine mapping,it is possible to identify the genes that control the tomato leaf angle,and the obtained results are expected to be applied to cloning.The research methods and conclusions are as follows:1.Genetic analysis showed that the tomato leaf angle trait was controlled by two major genes.This study investigated the leaf angle of 200 F₂ populations constructed with Heinz 1706 as the female parent and 161-817 as the male parent.The statistical results show that the phenotype of the F₂ population is Continuous distribution,indicating that the angle of tomato leaves is a quantitative trait controlled by multiple genes;2.Using the BSA method and QTL mapping,two candidate regions were mapped on chromosome10.For BSA,F₂ population was selected to construct DNA pools.The two DNA pools consisted of an equal amount of DNA from 20 F₂ individuals showing the most extreme leaf big and small leaf angle phenotype,respectively.The DNA pool was analyzed using 236 markers,showing polymorphism in the two segments of chromosome 10.Further,QTL analysis was performed on the chromosome 10 using 10polymorphic markers for the F_2:3 population.Finally,two major QTLs related to the leaf angle were detected,and the genetic contribution rates were 18.7%and 22.5%,respectively.These two main QTLs are named LA1-1 and LA1-2.3.Combination with the genotypes of F₂ recombinants individuals and phenotypes of F_2:3:3 families,LA1-1 was mapped to markers A-10 and A-5 on chromosome 10.Based on Heinz 1706 genome sequence,the physical distance between the two flanking markers,A-10 and A-5,was proximately 1.5 Mb,which contained 210 genes,and four of genes contains non-synonymous mutations?Solyc10g008620?Solyc10g008970?Solyc10g008990?Solyc10g009055?.It was found that Solyc10g009055 expression levels was significantly different between the parents.This gene may be a candidate gene for LA1-1.4.LA1-2 was mapped between markers B-3 and B-9 on chromosome 10.Based on Heinz 1706genome sequence,the physical distance between the two flanking markers,B-3 and B-9,was proximately378 kb,which contained 32 genes,and five of genes contains non-synonymous mutations?Solyc10g054760?Solyc10g054950?Solyc10g054970?Solyc10g054980?Solyc10g055020?.It was found that the gene Solyc10g054760 had a large difference in expression between the parents.Solyc10g054760is a member of the SAUR?auxin response gene family?and is involved in the auxin signaling pathway.This gene may be a candidate gene for LA1-2.