Identification of molecular marker linkage to yield-related of tomato ( Lycopersicon esculentum Mill ) under heat stress

• Main Authors: Wei-Lun Yeh, 葉偉倫
• Other Authors: Kuan-Huang Lin
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/73571763928345094833

碩士 === 中國文化大學 === 生物科技研究所 === 94 === Heat stress may inhibit the physiological and biochemical mechanisms of tomato, and result in declining yields of the tomatoes. The activities and numbers of pollen, germination of pollen tube, flower number, fruit number, size and ripening of tomato are highly related to high temperature. During summer season in Taiwan, the production of tomato is decreased due to high temperature and high rainfall combination. Most tomato varieties are adaptive to warm and dry weather, and don’t show heat tolerance. Heat tolerance of tomato is a quantitatively inherited trait and easily affected by environmental conditions. Therefore, marker-assisted selection (MAS) may improve the traditional field selection A total of 158 F2 plants derived from a heat tolerant CL 5915 crossed with a heat sensitive L4422 (L. Pimpinellifolium) were grown in the screen house at PCCU from May to September in 2004. Seven heat tolerance-related traits were scored: flower number, fruit number, fruit set, fruit weight, fruit yield, brix and seed number. The phenotypic data and correlation coefficient between traits were calculated. The objectives of this study were to identify and map the QTL linked to the heat tolerance traits in tomato, and to develop a database that enables use of RAPD and ISSR markers as selection tools for further improving heat tolerance in tomato. The results show that 11 significantly positive correlation coefficients were found between the traits. Polymorphic bands were generated by 3 RAPD primers and 100 ISSR primers using PCR with optimal annealing temperatures. Informative bands were used for χ2 goodness-of-fit 3:1 test. Combination of the mentioned 7 traits and the informative markers, four linkage groups were constructed, and 23 QTLs of traits linked to the markers were identified using Mapmaker/Exp 3.0b and Mapmaker/QTL 1.1b softwares. Among these QTLs, 6 of them linked to yield on the groups of 2, 3 and 4, 3 linked to fruit weight on groups of 2 and 3, etc. Nevertheless, all these 23 markers didn’t show any linkage to the seed numbers. In general, different genes controlled different traits, and the same trait was controlled by different genes appeared to be specific to high temperature environment. This work will expedite access to genetic variation necessary for ongoing crop improvement, and it will accommodate expansion of the production area in response to economic or climate demands, thereby reducing the environmental vulnerability of worldwide agriculture. MAS will not be fully accessible to plant breeders until the establishment of a procedure which is simple, rapid, accurate, efficient, cost effective and complementary to existing breeding protocols Keyword： tomato、heat tolerance、RAPD、ISSR、QTL, Marker-assisted selection