Abstract

Tripsin inhibitor(Ti) activities in sweet potato(Ipomoea batatas Lam.) leaves and roots from five local cultivars were analyzed on 15% SDS-PAGE. At qualitative level, it showed that two forms of Ti were present in both organs, with Mr. 31000 Da and 14000 Da in levels, and Mr. 31000 Da as well as 21000 Da in roots, respectively. At quantative level, the Ti activities varied among this cultivars. The level of trypsin inhibitory activity was closely related with pest resistance. More Ti activity conferred strong insect resistance on several cultivars, i.e. Tainong 34 and 65. Finally, the data of immunostain with anti-sporamin antiserum demonstrated that Tis from leaves were different from those of roots in sweet potato.

中文摘要

利用蛋白質膠體技術分析不同品系間甘藷(Ipomoea batatas Lam.)胰蛋白酶抑制因子的活性，發現塊根及葉部的胰蛋白酶抑制因子活性在不同品系間有所差異。甘藷的葉部組織中，台農九號、34號、57號和65號均有兩種胰蛋白酶抑制因子，分子量為31kDa及14kDa，其中65號的胰蛋白酶抑制因子活性最強，9號的活性最弱。而在台農27號、34號、57號和65號的甘藷塊根中，均有兩種胰蛋白酶抑制因子，分子量為21kDa及31kDa，57號另有一個33kDa的胰蛋白酶抑制因子。其中27號和57號的胰蛋白酶抑制因子活性較強，34號和65號的活性較弱。此結果顯示，葉部之胰蛋白酶抑制因子之活性高低，羽田間栽培試驗的抗蟲能力有正相關。 經由西方轉漬法(Western blotting)分析甘藷塊跟與葉部組織的胰蛋白酶抑制因子，顯示葉部之胰蛋白酶抑制因子和塊根有所不同。

Keyword: Sweet potato, Ipomoea batatas, Trypsin inhibitor(Ti), Insect-resistant group, Insect-labile group.