Traits Investigation Of Wild Tomato Species And Preliminary Mappling Of Conditional Spontaneous Blister Gene In S.Habrochaites

As a wildly-planted vegetable all over the world,tomato(S.lycopersicum),has gained great progresses in its extensive studies such as plant development,fruit quality and stress tolerance.With the decrease of genetic variation of cultivated tomato,wild tomato species are being given more attention due to its abundant genetic diversity in special fruit quality and stress resistance.The study and utilization of excellent alleles from them will be a significant direction in tomato research.As a consequence,it is quite necessary to collect wild tomato species and investigate their related traits in depth.In this study,we propagated several wild tomato species collected by our group,and investigated intuitive morphological characteristics including stem,leaf,flower and fruit,according to guide books and references on the criterion of tomato traits investigation.On the basis of this investigation,we conducted a study of preliminary gene mapping of a special phenotype(conditional spontaneous blister under greenhouse condition)on S.habrochaites.The main results were as follows:1.Plants of cultivated tomato(S.lycopersicum)and eight wild tomato species with 32 accessions in total were planted and their traits regarding stem,leaf,flower and fruit were investigated.A conclusion was made on the prospective utilization of the main traits of them.These wild tomato species are S.chilense,S.chmielewskii,S.habrochaites,S.neorickii,S.pennellii,S.peruvianum and S.pimpinellifolium.2.S.habrochaites accession LA1777 shows a phenotype of Conditional Spontaneous Blister(CSB)under greenhouse condition.The result of phenotype investigation in F2 population of the cross between LA1777 and a single-leaf mutant and F1/F2 population the cross between LA 1777 and A101 under greenhouse condition indicated that the CSB phenotype is conferred by a single dominant gene.3.At the bases of genome sequence alignment between S.pimpinellifolium accession LA1589 and a tomato cultivar Heinz 1706 to gain InDel locus from each chromosome,primers were designed according to border sequence of the InDel locus,polymorphisms between parents LA1777 and the single-leaf mutant were tested and polymorphic InDel markers were used to analyze genotypes of F2 individules with recessive phenotype of CSB.The preliminary result of gene mapping revealed that CSB gene was located near two mega base pair region on chromosome five and it was genetically linked to markers C5D152 and C5D27.4.Paraffin section was applied to reveal the morphological development of blister on leaves of LA1777.The results of cross-section through the leaf showed that the formation of CSB were due to the hypertrophy and swollen of the palisade cells.