分子蔬菜育種

Molecular Vegetable Breeding

蔬菜為人類生活必需品，種類繁多，食用部位及形態上差異極大，包 括根、莖、葉、花、果實及種子等，因此在育種時需要考慮食用部位之產量與品質。為滿足消費者選購時偏好之多樣化，並維護地球生態環境，蔬菜育種目標包括耐旱、耐濕、耐鹽、耐熱、耐寒、抗病、抗蟲、豐產、具高營養價值、適合機械採收、能酎長程運輸且能保持良好外觀及品質等。作物育種主要為增加基因型之變異，後由表現型選拔合乎育種目標的品種。傳統育種即利用雜交或突變以增加基因型變異，後由形態上或由可檢測之特性選出合乎人們需要之品種。本文就分子標誌應用於蔬菜育種之優劣點，基因轉殖應用於蔬菜育種之實例，討論植物分子生物學應用在蔬菜育種之可行性與展望。分子標識可以直接辨識基因型而且大多具有共顯性，且在植物任何生育期均可測定，故可加速育種選拔效率，其已被應用於蔬菜分類、種源鑑定、種子純度檢查、建立基因連鎖群圖譜及鑑定重要性狀相關基因等。利用基因轉殖技術，由於甚因可來自不同之植物、動物、或其他微生物，可以克服有性雜交之限制而提高育種效率，縮短育種年限。

Vegetables are human's staple food. They varies in terms of edible parts and morphology, and their kinds are numerous. The edible parts include roots, stems, leaves, flowers, seeds and fruits. Therefore, the yield and quality of vegetable's edible parts needs to be taken into account while engaging in breeding. In order to satisfy the consumers' preference for variety and protect the environment of the earth, the desirable genetic traits for vegetable improvement are drought tolerance, flooding tolerance, salt tolerance, heat tolerance, cold tolerance, disease and insect resistance, high yielding, high nutritional value, machine harvestibility and long shelf life. Plant breeding should be aimed at increasing the variation of genotypes followed by screening out the phenotype possessing traits we need. Traditional breeding utilizes hybridization and mutation selection to increase the variation of genotypes, and according to its morphology or detectable characters, choose the variety which meet the requirements. This paper focuses on the benefit of molecular markers applied to vegetable breeding, the empirical study of gene transfer applied to vegetable breeding, and the possibility and prospects of the application of plant molecular biology to vegetable breeding. Molecular markers are generally codominant, they not only can be used to identify the genotype directly, but also can be detected in any stage of breeding. Thus, it can enhance the efficiency of selection and has been used in vegetable classification, homology identification, seed purity examination, gene linkage map construction, and identifying the trait loci. Due to the fact that genes can be isolated from different plants, animals, or microbes, the techniques of gene transfer can be used to overcome the limitation of sexual hybridization, to increase the efficiency of breeding, and to reduce the time frame of breeding.