Selection and Application of Fusarium Wilt Resistant Rootstock of Asparagus Bean (Vigna unguiculata)

豇豆 (Vigna unguiculata) 為台灣夏季重要的蔬菜種類之一，以“三尺青皮”為主要品種，其具豐產及品質好之特性，但此品種對萎凋病(Fusarium oxysporum f. sp. Tracheiphilum)不具抗性，連作時此病害發生嚴重而影響產量。為解決豇豆萎凋病的問題，本試驗從12個豇豆供試品種 (品系) 中，篩選出具有耐萎凋病的根砧-代號"I"品種，並以此品種為根砧，嫁接4個不同接穗品種，結果顯示嫁接存活率均高達93%以上，可知代號"I"根砧品種對4個接穗品種均有良好的親和性且生長良好。"三尺青皮"品種之播種苗在1 x 104菌液濃度時的發病率為85%，以"I"品種為根砧，三尺青皮為接穗的嫁接苗，在1 x 104菌液濃度時發病率為0%，在1 x 106濃度時發病率僅有28%，此顯示根砧品種具有耐病性。為測試耐萎凋病根砧之嫁接苗在田間生長及存活情形，在溫室內進行連作，結果以“三尺青皮”品種的實生苗成活率最低約18%；嫁接苗的部分，所有品種的成活率達96%以上，產量以“三尺青皮”品種的實生苗產量最低，嫁接苗之成活率高，且產量明顯增加。另外，選擇連作且萎凋病發生嚴重的產地田區進行嫁接苗耐病性試驗，實生苗在定植1個月後即全株萎凋死亡，成活率0%；嫁接苗仍有80%的成活率，顯示耐病根砧可以提高田間存活率並穩定產量。 Asparagus bean (Vigna unguiculata) is an important vegetable in summer cropping in Taiwan. "3 Feet Green Peel" is the major variety with high yield and good quality. However, it is not resistant to Fusarium wilt (Fusarium oxysporum f. sp. Tracheiphilum), which causes severe losses in asparagus bean fruit production. In order to solve the problem, 12 asparagus bean varieties were collected and screened for resistance against Fusarium wilt, the results showed " I " variety had good Fusarium wilt resistance for rootstocks. The Fusarium wilt resistant rootstock (" I " variety) grafted with four different scion varieties had the average survival rate up to 93% ,which showed its good grafting compatibility. The disease incidence of seed seedlings of "3 Feet Green Peel" variety inoculated in the spores solution with concentration of 1 x 104 and 1 x 106 were 85% and 100%, respectively. However, the disease incidence of grafted plant ("3 Feet Green Peel"+"I") inoculated in the same concentration were 0% and 28%, respectively. The plant survival rate of seed seedlings and grafted asparagus bean planted in production field at 4th continuous cropping were 0% and 80%, respectively, indicating using resistant rootstock could improve the survival rate in the field and stable the yield