抗感水稻品种受灰飞虱为害后的生理反应差异

Differences in the physiological response of resistant and susceptible rice varieties infested by the small brown planthopper

灰飞虱Laodelphax striatellus Fallén(SPBH)是我国水稻生产上的一种重要害虫。为探明水稻抗灰飞虱的生理基础,在不同灰飞虱虫口密度(0、5、10、20头/株)及不同为害时间(3 d、6 d)下,检测了抗感水稻品种相关生理指标的变化差异。结果表明,灰飞虱为害后,抗感水稻植株中叶绿素、可溶性糖及可溶性蛋白含量均呈下降趋势,感虫品种中的下降幅度显著大于抗虫品种,且感虫品种的叶绿素、可溶性糖及可溶性蛋白含量在不同虫口密度及不同为害时间下,均存在显著差异。当灰飞虱以20头/株为害6 d后,武育粳3号、Kinmaze、DV85和Mudgo中叶绿素下降幅度分别为46.0%、46.0%、2.3%和2.1%,可溶性糖含量下降幅度分别为55.5%、46.3%、9.2%和11.7%,可溶性蛋白含量下降幅度分别为22.3%、29.5%、8.5%和6.7%。抗感水稻中过氧化物酶活性随虫量增大和为害时间延长而显著升高,过氧化氢酶活性则随虫量增加和为害时间延长而降低,但抗虫植株中保护性酶活性对虫害胁迫的响应明显早于感虫材料。游离脯氨酸和丙二醛含量均随着灰飞虱虫量增大及为害时间延长而上升,其中,游离脯氨酸在抗虫材料中的上升幅度高于感虫品种,丙二醛含量则在感虫品种的上升幅度显著高于抗虫材料。

The small brown planthopper （SBPH） , Laodelphax striatellus Fall6n （Homoptera： Delphacide） , is a serious pest of rice （ Oryza sativa L. ） in China. To elucidate the physiological basis of the resistance of rice to SBPH, we measured some physiological indices in rice seedlings infested by O, 5, 10 and 20 of these pests per seedling for 3 d and 6 d. The results show that although chlorophyll, soluble sugars and protein tended to decrease in all the tested rice varieties this trend was much greater in the susceptible than in the resistant varieties. Levels of chlorophyll, soluble sugars and protein in susceptible varieties were significantly different at different densities and durations of SBPH infestation. Rice seedlings of the Wuyujing 3, Kinmaze, DV85 and Mudgo varieties infested by 20 SBPH per seedling for 6 d displayed a decrease in chlorophyll content of 46. 0% , 46. 0% , 2.3% and 2.1% , respectively whereas soluble sugars in the above four varieties decreased by 55.5% , 46.3% , 9.2% and ll. 7% and soluble protein by 22.3% , 29.5% , 8.5% and 6. 7% , respectively. The activity of peroxidase （POD） significantly increased and that of catalase （CAT） decreased with increasing density and duration of SBPH infestation in all four rice varieties. Defensive enzymes increased in response to SBPH infestation significantly earlier in resistant than in susceptible varieties. Free proline and malondialdehyde （MDA） increased with the density and duration of SBPH infestation in all four varieties. However, although the increase in free proline was greater in resistant varieties than in susceptible ones the converse was true for MDA.