Study On The Distribution Of Heterodera Glycinesin Huanghuai Aera And The Resistance Mechanism Of Soybean Against Race 4 Of Heterdera Glycines

A total of 28 samples were identified during the survey for the distribution of soybean cyst nematode (Heterodera glycines Ichinohe) races in huanghuai area from 2001 to 2003. An outline map of race distribution was given according to the results of this experiment and other reports. Race1, 4 were predominant in this area and race2, 5, 7, 9 were alsofound. The rule of race distribution was discussed preliminarilyï¼›Three different resistant cultivars of soybean, high disease-resistant or sensitive, were used to study the dynamics of PAL, POD and SOD activities in the course of SNC R4. The result showed that there were evidently differences in PAL, POD and SOD activities in resistant and susceptible soybean varieties. The PAL, POD and SOD activities should be considered as a physiological index to evaluate the resistant to SCN R4ï¼›The penetration and development of race 4 of Hetreodera glycines were studied with roots of highly resistant soybean, yingxianxiaoheidou and xingxianhuipizhi ,and susceptible control,yudou25.Variance analysis showed that there is no significant difference for the numbers of second stage juveniles(J2) and total between in resistant and in susceptible soybean roots in the early stage after inoculation. In the upper after inoculation, the average numbers per plant and percentages of second stage juveniles (J2), third stage juveniles(J3) of Heterodera glycines were significantly higher on resistant roots than that onsusceptible roots.