抑制大豆胞囊线虫的异黄酮种类研究

Suppression of different soybean isoflavones on Heterodera glycines

为明确外源异黄酮类物质对大豆胞囊线虫的毒性,选取黄豆苷元(daidzein)、黄豆苷(daidzin)、染料木素(genistein)、染料木苷(genistin)、黄豆黄苷(glycitin)和黄豆黄素(glycitein)6种大豆异黄酮,采用贝氏皿法离体测定其对大豆胞囊线虫的卵孵化抑制率和对二龄幼虫(J2)的致死率及其田间防效,以明确对线虫有效的异黄酮种类。结果表明:6种大豆异黄酮对胞囊线虫的卵孵化和J2活性均具有一定的抑制作用,其中100μg/m L染料木素效果最好,处理24h后,对J2校正死亡率可达到45.46%,对卵孵化抑制率为43.48%,且50μg/m L染料木素处理种子后的田间防效显示对胞囊抑制率亦达到49.47%。此外,染料木苷和黄豆苷元对J2和卵孵化也有较明显效果但田间防效较其他异黄酮差;黄豆黄苷和黄豆黄素对J2毒杀作用较弱但对卵孵化抑制作用较强;黄豆苷对J2和卵孵化作用效果最弱,但是其田间防效与染料木素无显著性差异。说明供试的6种异黄酮在不同浓度和条件下均对大豆胞囊线虫有抑制作用,以染料木素的综合效果最好。研究结果为解释大豆抗线虫侵染的机制及利用大豆异黄酮防治线虫病害奠定了理论基础。

In this study,6 exogenous soybean isoflavones,including daidzein,daidzin,genistein,genistin,glycitin and glycitein,were selected to identify the inhibition efficiency on H. glycines. Nematicidal efficacy of these isoflavones was investigated through inhibition of egg hatching and mortality of second-stage juveniles（J2）. In addition,field efficiency trials of seeds soaked with isoflavones were determined. The results showed that all 6isoflavones could inhibit H. glycines to some extent,and genistein had the highest mortality of 45. 46% on J2 and inhibition rate of 43. 48% on egg hatching at concentration of 100 μg/m L after 24 h treatment,also had inhibition rate of 49. 47% at concentration of 50 μg/m L in field trials. Genistin and daidzein significantly killed J2 and inhibited egg hatching,but their control efficacies were weaker than those of others in field trials. Glycitin and glycitein had weaker toxicity on J2 and higher inhibition on egg hatching than genistin and daidzein. Furthermore,daidzin showed the weakest inhibition of J2 and egg hatching than other 5 isoflavones in vitro in plant nematology laboratory,but its control efficacy in the field showed no significant differences compared with genistein. The research confirmed that soybean isoflavones had positively suppressive ability on H. glycines,especially genistein,showed better comprehensive efficacy. The results suggested that isoflavones played an important role in resistance mechanism of soybean against nematode infection,and also provided clues in control soybean cyst nematode by soybean isoflavones.