番茄果實硬度及厚度相關基因座之分子遺傳分析

Molecular Genetic Characterization of Fruit Firmness and Thickness Loci in Tomato

果實完熟的過程影響水果的品質與口感，如澱粉與糖之轉換、顏色、硬度、風味及質地等改變，故深入了解果實成熟調控機制十分重要。目前，番茄是研究果實成熟的模式植物，其中，番茄品系Y73具有正常果實成熟過程，成熟後呈鮮紅色，但其硬度極高，顯示後熟期間軟化延遲，本研究的目標即針對番茄品系Y73，篩選與果實硬度及厚度相關的分子標誌。首先將果實硬度極高的Y73與軟果實品系Y84雜交，建立F2族群，利用增幅片段長度多型性（amplified fragment length polymorphism，AFLP）技術結合群組分離分析（bulk segregant analysis，BSA），結果在選殖四個AFLP片段中，親本間E2M2 560與E4M3 260的增幅片段並無多型性，反之，E6M3 290與E6M3 300增幅片段在親本間有清楚的多型性條帶，故進一步分析其在F2族群分離率與性狀的相關，結果顯示片段E6M3（下標290）與E6M3（下標300）均與果皮厚度有顯著相關，但與果實硬度並無顯著相關。 Fruit ripening is a key step to the quality and mouthfeel of fruits, including interconversion between starch and suger, the changes of fruit color, firmness, flavor, and texture. It is important to understand the mechanisms controlling fruit ripening. Tomato is a popular model plant for fruit ripening study. One of tomato lines, Y73, shows normal fruit ripening but remains firm, indicating that the process of fruit softing has been delayed. In this study, an F2 population derived from the cross between Y73, a firm-fruit line, and Y84, a soft and normal ripening line, was constructed and surveyed by amplified fragment length polymorphism (AFLP) combined with of bulk segregant analysis (BSA). The AFLP fragments, E2M2(subscript 560) and E4M3(subscript 260), showed no polymorphism between parents. However, E6M3(subscript 290) and E6M3(subscript 300) showed clear polymorphism. Further tested in F2 population reveal that E6M3(subscript 290) and E6M3(subscript 300) had significant correlation with the thickness of fruit pericarp but the correlation with fruit firmness were not significant.