The Study Of Gene Molecular Markers On Southern Room-knot Nematode Resistant Of P. Kansuensis L.

Peach is a important fruit which be planted widely in the world, Root-knot nematodes (Meloidogyne spp.) are one of the most serious parasites in peach (Prunus persica (L.) Batsch) as well as of the other Prunus species and the family Rosaceae. Rootstock breeding is dominating approach to solve the problem. With developing of marker assisted selection (MAS), Select a marker linked with gene of resistance to root-knot nematodes is became more and more concern.In peach, the primary nematode was found to be M. incognita. 190 population derived from the cross of a material which is immune to Mi,honggengansutao(P.kansuensis)and a material which is infected to Mi, Beilei[Prunus persica (L.) Batsch] were studied in the paper, A linkage map of peach was constructed with SSR and SRAP markers, and the Mi gene was located in the linkage. It would be very useful to introgress root-knot nematode resistance genes into other resistance rootstock germplasm (resistance to crown gall and drought stress).The mechanism of resistance to Mi in Honggengansutao was preliminary studied in the paper.The main results were below:(1)190 BC1 populations were inoculated artificially separately on potted to evaluate their resistance to Mi in open field.107 progenies were susceptible to Mi. and 83 progenies were remarkable resistant, the result was evaluated by the 2 test for goodness of fit against a 1:1 ratio for the dominant markers.(2)CTAB method was used to extract DNA from young leaf for SSR and SRAP analysis. SSR system is a 10-μL volume containing 1.0μL template DNA, 1.0μL 10×PCR buffer(MgCL2), 0.6μL dNTP, 0.35μL of each primers(10mM), 1 U DNA polymerase and 6.5μL ddH2O. SRAP system is also 10-μL volume containing 1.0μL template DNA, 2.0μL 10×PCR buffer(MgCL2), 0.6μL dNTP, 0.3μL of each primers(10mM), 1 U DNA polymerase and 5.6μL ddH2O.(3)Two bulks were established using different BC1 individuals from the cross: bulk 1 and bulk 2 were formed by pooling DNA from 5 resistance and 5 susceptible individuals, respectively.135 SSR and 64 SRAP primers were screening through the parents, pool and some individual. The selected primers including 39 SSR and 43 SRAP with rich polymorphism and steady bands were tested in progeny. 141 markers in 1:1 ratio by X2 test were scored. Mapmaker software were used to assign the markers to 8 linkage groups, the map covers 1267.3 cM of the peach genome. The average length of groups is 158.4 cM, the average distance between adjacent loci is 13.2 cM.(4)According to the results of inoculated,The gene of resistance to Mi (Mi-redkansu)was located in the map,After comparative analysis the same SSR loci between the map in the paper and the reference map of Prunus (T×E), Mi-redkansu was placed on the top of group2 (Chromosome 2),the nearest linked marker was M8E1-95, 4.7 cM。(5) Then selected the specific primer in the current anti-known of Meloidogyne incognita on peach varieties verified and found that resistant varieties are in a position 95bp obvious bands, rather than anti-root nematode species is not this band.