Study On Histopathology And Related Genes Of Soybean Resistant To Heterodera Glycines

The dynamic changes were observed of J2 of Heterodera glycines in the different soybean cultivar roots after invasion and the histopathological differences were compared and the syncytium formation-related gens expression was analysis among different soybean reisistant cultivars.The main results were as follows:1.The comparative study of two methods of slices and optimizing the frozen section:Comparison of the frozen section method and paraffin section method of soybean root which has a different advantage in the study of soybean root histology.One of the method was determined to study of young soybean root tissue applies.Further more we optimized the steps of frozen section.The result showed that:yong soybean root sliced broken chance and the embedding of bubbles can be reduced by a method of in a tin bucket first quick-frozen after embedding. Second using paraffin section technique for young soybean root histologic study can obtain good effect of slice.Thus we can draw a conclusion that applying the technology of paraffin section is suitable for soy young root histologic study.2.The comparative histological structure of different resistant soybean roots to soybean cyst nematode:Paraffin sections technique were used to compare the histological structure of different resistant soybean roots,aimed to determine the resistance mechanism of different small black soybean cultivars.The result showed that:in the early days of infection there was no significant difference in the numbers of second stage juveniles inside soybean roots between different resistant cultivars.The formation of synctium in the resistant cultivars was earlier than susceptible cultivars. Harbin small black soybean early formed the syncytial in stele and hardly resistant the invasion. With the nematode infection,resistant cultivars evolved hypersensitive reaction to prevent nematode development forming a very small number of female in roots where almost no females formed in Hui pizhi small black soybean root, the strongest anti-development. Susceptible cultivar Liaodou 15 had no hypersensitive response occurred within the root formation of a large females.In the host’s vascular bundles, the xylem of Susceptible cultivar Liaodou 15 moves outward and the xylem vessel will be reduced in the late infection that was not conducive to the safety of water transportation.However,the structure of xylem was not changed in the three resistant cultivars and it was good for the growth of soybean.3.Soybean cyst nematode infection in the soybean root syncytium formation related gene expression:Actin as internal genes,four syncytial growth related genes in the soybean roots ATCEL2(1,4-β-glucanase),ATEXPA3(expansin),LEEXPA4(expasin),UGD2(Glucose dehydrogenase) was selected to do real-time fluorescence quantitative reverse transcription-pcr after innoculated with J2 among resistant cultivar Huipizhi and susceptible cultivar Liaodou 15. The result showed that:15 days after innoculated with J2 the expression was obviously up regulation in the Liaodou 15 cultivar compared to the control,it maybe caused by the needs of root female nutritional during the development of the gradual increase in the amount of syncytial strengthen metabolism wheares the expression was down regulation in the Huipizhi cultivar which might be caused by the produce of hypersensitive response in root inhibited the formation of syncytia and making it difficult to obtain nutrition for nematodes thus can not reproduce inside.