Seed-Coatings Control Of Heterodera Avenae On Wheat, Resistance Evaluation Of Soybean Varieties And Germplasms To Heterodera Glycines And Their Interaction Characters

Cyst nematodes are important plant pathogens that cause serious diseases and widely distributed in the world. Cereal cyst nematodes (CCN) and soybean cyst nematode (Heterodera glycines, SCN) are obligate endoparasitic nematodes with economic importance. Exploring economic and effective control methods together with the study of interactions between nematodes and host plant has great significance in the integrated control strategies of cyst nematodes.Effects of six kinds of seed-coatings, including Gannong seed-coatings Ⅰ, Ⅱ and Ⅲ, abamectin seed coatings AV1and AV2, and5.76%emamectin benzoate, were evaluated on controlling Heterodera avenae of wheat under field conditions. Wheat seeds were coated with eight different treatments before sowing and the changes in number of cysts in soil and yields were compared after wheat harvesting. The results showed that the numbers of cysts in soil collected from different treatments were clearly dropped after seeds-coating. The treatment of Gannong seed coating Ⅲ (1:35), Gannong seed coating1(1:50), Gannong seed coating Ⅱ (1:35) has the higher revision cyst reduced rate, with56%,53%and47%, respectively. The wheat yields were increased when compared with the control. The yield of treatment of Gannon seed coatingⅢ1:35), Gannon seed coating Ⅰ(1:50), Gannon seed coating Ⅱ (1:35) and Gannon seed coating Ⅰ (1:35) was increased by58.7%、22.7%、20.4%and20.0%, respectively. The self-patented Gannong seed coating Ⅲ not only has better control efficacy on CCN, but also has characteristics of environmental safety, lower toxicity, labor and cost saving, which is suitable for widely application in practical disease control.Planting resistant cultivars is considered as the most economic and effective method for prevention and control of cyst nematodes. In order to screen the resistant materials to race4of Heterodera glycines,403cultivars and germplasms were tested by second stage juvenile (J2) inoculation under greenhouse and field trial. The results show that no material was evaluated as immune to SCN. There are35soybean germplasms performed stable resistance to SCN, in which Y191was the high resistant, while34soybean germplasms including Z61, Z62and Z101showed the moderate resistance. These screened materials can be used as resistance resource for future plant breeding.The interactions between the root tips of soybean with different SCN resistance and the J2s of H. glycines were studied using Pluronic F-127gel as a medium. The results showed that the root tips of soybean cultivars with different resistance were all able to attract juveniles of SCN. The tissue staining revealed that the large number of juveniles was capable to penetrate into root system regardless of the variety resistance. However, the growth of juveniles was gradually stopped in resistant cultivars, which may suggest the suppressing function for nematode growth. The results provided the basis for further study on interaction mechanisms for these resistant germplasm materials.