Morphological And Physiological Characteristics In Tomato And Fine Mapping Of The Positional Male Sterile Lst Gene

The use of tomato sterile plants for the production of hybrid seeds can eliminate the traditional castration,so it has important application value for the production of hybrid tomatoes.Tomato L-type male sterility in this study means that stamens have normal development and the ability to produce viable pollen.However,the stigma is higher than the stamens because of the abnormal style.As a result,infertility is caused by failing to complete fertilization.The self-fertility rate of L-type male sterility is low in high temperature and it has two different uses in just one line.So it has great application value and research potential.The study has been researched from three aspects including morphology,physiology and gene location.The specific method is to use paraffin section to observe the structural changes and reasons for sterility.Content changes of five kinds of hormones in different styles at different times are analyzed by high performance liquid chromatographyuse the method of parental re-sequencing and Super BSA to locate the sterile gene of tomato.The results are as follows:.(1)The number of vascular bundle in sterile style is more than that in fertile style significantly.At the same time,we can observe that the diameter of sterile style is longer than that of fertile style.There is no significant difference in the size of style cells between the fertile and the sterile from which we can get the conclusion that style elongation is caused by the increase of the number of style cells rather than larger cell volume.The ovary of the sterile developed normally and its number of chamber and ovule is more than that in the fertile.This provides a physiological basis for future crossbreeding and the obtaining of maintainer line.We also find when the flower bud is 0.5-0.7cm,part of placentas in middle ovary differentiate to more chambers and ovules.(2)The GA3 content in sterile material and fertile material are basically the same,but GA3 in sterile style is always higher than that in fertile style.The IAA content in sterile style shows a rising trend and the fertile style is relatively stable.When the flower bud is 0.9-1.1cm,the IAA content of sterile style exceeds that of fertile style.The ZT content in fertile style is higher than that in sterile at the beginning of flower development.With the increasing of ZT,the situation has reversed in the late development of flower buds.The ABA content in fertile style is steadily increasing from the whole,while in sterile material T431,the content is more stable.In the early stage of flower development,the content of ABA in the pistil of contrast material is lower than that in sterile variety.After the flower bud is 0.9cm,the content of ABA in contrast material increased rapidly and exceeds the content of ABA in sterile material.The changes of the content of salicylic acid at different times in T431 and contrast materials are in the opposite direction,which may be related to the high temperature stress response of the material itself.(3)The F1 hybrids are all fertile with T431 as male parent and controllable fertile species as female parent.We can obtain 167 fertile plants and 56 sterile plants in generation F2.The result matches the separation ratio 3:1 which prove that the genes which control the sterility of T431 is cell nucleus recessive.(4)Use Super BSA and parental re-sequencing to locate the tomato sterile genes.Finally,a total of 67.74 Mreads are obtained from parental re-sequencing.29.63 Mreads are obtained from filial generation gene pool sequencing.A total of 154,756 SLAF tags are developed.The average sequencing depth of gene poor is 72.22 x and the total sequencing depth is 144.43 x.Do polymorphism analysis to the SLAF tags and a total of 1691 polymorphic SLAF tags are obtained.Also,through detection and filtration we can obtain 9411 SNP locus.Through association analysis,the target gene is located to two regions of SL2.40ch12 chromosome with size of 1.75 Mbp and 3.15 Mbp.We find 26 candidate genes in the candidate area.To search the information and analyze the function of the 26 genes,Six genes named Solyc12g082730.1,Solyc12g077680.1,Solyc12g077670.1,Solyc12g027610.1,Solyc12g027690.1 and Solyc12g027710.1 could be found,the function of which are closely linked to target character.This study has provided the theoretical basis and genes for the further investigationof sterile genes in tomatoes.