炎炎夏日,，以西瓜為代表的各種瓜類成為人們最愛。美國科研人員最新報告說,，他們繪制出了西瓜等瓜類的基因組圖譜,，將來有望利用基因技術開發(fā)出更甜,、更可口、更健康的瓜類新品種,。
得克薩斯農(nóng)機大學科研人員在新一期《美國園藝科學協(xié)會雜志》上報告說,，此前法國和西班牙研究人員曾經(jīng)完成了瓜類某些DNA（脫氧核糖核酸）片段的圖譜繪制工作,。而得克薩斯農(nóng)機大學研究小組在此基礎上通過瓜類雜交,，得出了瓜類的完整基因組圖譜,。
研究人員說，除了瓜類的完整基因組信息,，他們還在實驗中識別出了瓜類的一些最重要基因,，比如負責調控糖分的基因、與維生素C有關的基因等,，這些對于培育新的瓜類雜交品種都十分有用,。下一步,，研究人員還將從基因組圖譜中識別出與瓜類抗病,、耐旱、形狀,、大小等有關的各種基因,。（生物谷Bioon.com）
生物谷推薦原始出處：
J. Amer. Soc. Hort. Sci. 134: 67-76 (2009)
A Genetic Linkage Map including Loci for Male Sterility, Sugars, and Ascorbic Acid in Melon
Soon O. Park1, Hye Y. Hwang and Kevin M. Crosby
Vegetable & Fruit Improvement Center, Texas A&M University, College Station, TX 77845; Texas AgriLife Research and Extension Center, Texas A&M System, Weslaco, TX 78596; and the Department of Horticultural Sciences, Texas A&M University, College Station, TX 77845
Our objectives were to construct a randomly amplified polymorphic DNA (RAPD) marker-based linkage map using an F2 population derived from the melon (Cucumis melo) cross of ‘Deltex’ x TGR 1551, and map quantitative trait loci (QTL) for sucrose, total soluble solids (TSS), ratio of sucrose to total sugars (RSTS), and ascorbic acid as well as the ms-3 locus for male sterility previously reported in other muskmelon crosses. Due to the dominant character of RAPD markers, we scored 192 ‘Deltex’- and 158 TGR 1551-derived markers. One hundred eighty (94%) of the 192 markers fit the expected 3:1 ratio. On the basis of the 180 markers, we constructed a ‘Deltex’ linkage map of 171 markers distributed on 12 linkage groups (LGs) with a total map distance of 1182 cM. One hundred fifty (95%) of the 158 markers were identified to be nondistorted. We developed a TGR 1551 linkage map of 138 markers distributed on 12 LGs with a total distance of 1163 cM. A combined map of 12 LGs with a total map distance of 1394 cM was made from 82 marker pairs expressing codominance. Nine LGs were integrated into those of the existing composite map by 17 anchor markers. We mapped the ms-3 locus for male sterility on LG 9, which corresponds to LG 10 of the classical map and LG VII of the composite map. Six QTL for sucrose were located on LGs 2, 3, 4, 6, and 11. Three on LGs 3, 4, and 6 and four on LGs 2, 3, 6, and 11 of the six QTL for sucrose were also noted to be QTL for TSS and RSTS, respectively. A single QTL for ascorbic acid was placed on LG 5. This map will also be used to identify QTL for fruit sweetness, quality, size, and shape traits, as well as disease resistance.
