Glycoalkaloids as the resistant factor for potato disease.

本研究的目的是利用叶片和茎中的代谢中间产物进行土传病害的早期诊断。以马铃薯块茎中的糖苷生物碱含量作为马铃薯疮痂病侵染的指标进行了研究：1.研究了马铃薯块茎中糖苷生物碱含量的变化，结果表明，抗病品种块茎中糖苷生物碱含量高于感病品种，分析了糖苷生物碱的主要成分为α-龙葵碱和α-查可宁。马铃薯块茎中α-茶乌头碱的增绿率高于α-龙葵碱的增绿率。推测糖苷生物碱的增加步骤是从α-查乌头碱的增加开始，然后转移到α-结果表明：1.马铃薯块茎中的糖苷生物碱含量随绿化时间的延长而增加，表明马铃薯块茎中的糖苷生物碱具有植物抗毒素的作用茎上各叶位的糖苷生物碱含量均为上部3片叶的糖苷生物碱含量高于下部叶，说明上部叶中糖苷生物碱积累较多。对马铃薯疮痂病感病的德吉玛品种，其糖苷生物碱含量明显高于不感病的梅皇后品种，证实了糖苷生物碱含量与马铃薯疮痂病感病性呈正相关。

The purpose of this study is to use the metabolic intermediate in leaf and stem for early diagnosis of soil borne disease. Glycoalkaloids contents in potato were investigated for the indicator of potato scab infection.1.The change of Glycoalkaloids contents in potato tubers, in case of greening by sun light, that treatment was done instead of disease infection, were investigated.The Glycoalkaloids content in potato tubers of disease resistant variety was higher than susceptible variety.Analyzed Glycoalkaloid's components were alpha-Solanine and alpha-Chaconine. The increasing rate of alpha-Chaconine in potato tubers by greening, was higher than alpha-Solanine content.From these results, it is assumed that the step of Glycoalkaloids increasing start from the increase of alpha-Chaconine and then it transfer to alpha-Solanine increase.These increase of Glycoalkaloids in the potato tubers by greening shows that the total Glycoalkaloids have the function of phytoalexins.2.The contents of Glycoalkaloids in leaves of each position on stem were that the three leaves from top were much more Glycoalkaloids contained than lower leaves, these contents shows much Glycoalkaloids accumulate in upper leaves.The content of Glycoalkaloids in leaves of two potato variaties were investegated. The variety of Dejima, it is more susceptible for potato scab, contained more less Glycoalkaloids than none susceptible variety, May Queen.In this study, We could confirmed the positive relation between the contents of Glycoalkaloids and infection susceptibility on potato scab.