| Sesame(Sesamum indicum L.) is an important oil crop and it possesses high edible and nutritive value. Plant height of sesame is closely related to yield and stress-resistance. In this study, RIL population containing 548 lines was established to construct genetic linkage map. Based on constructed genetic linkage and phenotypic data,QTLs of plant heightrelated traits containing plant height(PH), Stem height from base to first capsule(SH), Capsule zone length(CZL),Top length without capsule(TL), Internode length(IL) and No. of capsule node pairs(NCNP) weredetected. To analyze the relationship between plant height and growth rate,we used liquid chromatography-tandem mass spectrometry(LC-MS/MS) to detect the contents of 3 endogenous phytohormonesincluding indole acetic acid(IAA), gibberellic acid(GA3) and abscisic acid(ABA)in the top 3rd leaves and stem tips of dwarfs and high height genotypes.Specificconclusions were as follows:Construction of sesame genetic linkage map: based on F6 RIL that established from Zhongzhi13(♀) and ZZM2748(♂)with extreme difference in plant height, a molecular genetic map comprising 344 PCR-based marker were constructed withJoinmap 3.0. In total, 1605.27 cM of data was obtained spanning cross the genetic map containing 14 linkage groups and the average density of marker per was 5.73 cM. In the total 14 linkage groups, the average genetic distance was 1.12cM-11.17 cM and molecular markers per group were 3-69.Correlations analysis among PH,SH,CZL,TL,IL,NCNP of sesame planted in Wuchang, Yangluo and Pingyu. The result showed that PH had significantly positive correlation with SH,CZL,IL and TL with correlationcoefficient of 0.58404,0.58404,0.44039,0.11117,which indicated that SH,CZL,IL can increase PH relatively while the change of TL has little influence on PH. CZL showed significant positive correlation with NCNP at 0.78914, which means the NCNP increases with the increase of CZL. NCNP showed significant negative correlation with IL, therefore short IL benefit to the increase of CZL.QTL location for plant height associated traits in sesame:QTLs related to PH,SH,CZL,TL,IL,NCNP were excavated with QTLNetwork-2.0 and WinQTLCart-2.5,most of which located in the groups of Lg1,Lg2,Lg3,Lg8,Lg10. We analyzed the phenotype data from three plant location respectively with WinQTLCart-2.5, obtained 61 QTLs of Wuchang, 62 QTLs of Yangluo and 89 QTLs of Pingyu. We detected 44 QTLs totally by using QTLnetwork, including 12 QTLs related to PH,9 QTLs related to SH,9 QTL related to CZL,3 QTLs related toTL, 5 QTLs related to NCNP, 6 QTLs related to IL.Analysis of the phytohormone change during the plant development: the two kinds of genotypes incresed sustainably from the 3 true leaf stage to terminal flowering stage, but the daily growth rate of the high height genotype was quicker than the dwarf genotype. During various developmental stages of plant height in two types of materials, obvious content variation characteristics of IAA in leaf and GA3 in stem tip were observed; There was no significant law of ABA content between two types in leaf and stem tip. Correlations analysis showed GA3 affected stem growth of sesame most significantly. |
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