| This research used the resistance genes tobacco south root knot nematode and PVY resistance-MSNR closely,the characteristics of the chain.PVY-MSNR replicase(PVY-NIB)is the induced factors produced dry spots in south root knot nematode resistant varieties after tobacco leaf inoculated PVY-MSNR virus.Synthetizing PVY-MSNR replicase gene,constructed PVX virus transient expression vector and established new technology identification system by which we could identify resistance gene of tobacco varieties against root knot nematode.Contrasts with identification of foreign PVY-MSNR virus inoculated directly or traditional disease resistance were used to verify the accuracy of identification system.Meanwhile,conducted the primary biological control research on root-knot nematodes.The results showed that:(1)Synthesized the replicase gene of PVY-MSNR artificially and constructed the PVX transient expression system,then transformed infiltrated tobacco leaf mediated by Agrobacterium GV3101.The varieties which were resistant to Meloidogyne incongnita showed the hypersensitive response on.However,no response were showed in the varieties susceptible to Meloidogyne incongnita.Constructed a new technology system to identify the root-knot nematode resistant gene.Then screened 19 germplasm materials that contained the root-knot nematode resistant gene and 6 resistance varieties,13 medial resistant varieties and 6 susceptible varieties according to the percentage of dry spot area of the total area.(2)Compared between gene identification and the traditional resistance identification,the gene identification technology results indicated that 14 species,for example T.I706,NC95,G-28,K326,Coker176,Coker86,Mc nair373,Speight G-15,Speight G-33,Speight G-52,中烟14,NC55,NC71,NC89,were resistant to root knot nematode,which was similar with the result of traditional resistance identification..(3)Compared between gene identification and traditional resistance identification,gene identification result showed that 14 varieties had resistance against Meloidogyne incongnita,which corresponded to the result of traditional resistance identification.(4)Compared between gene identification and the identification by inoculated during cultivation process,the gene identification suggested that nineteen varieties,such as T.I70 and YZ90,had resistance against Meloidogyne incongnita,while KY14,NC2326 infected by Meloidogyne incongnita,which was consistent with the result of traditional identification.(5)This study measured protective enzyme change after inoculate Meloidogyne incongnita in different resistance tobacco variety.The result demonstrated that POD,SOD and CAT differences were little.After inoculated,the SOD activity of the resistance variety lowered dramatically,during which the change of infected variety was more than it of resistance variety and enzyme activity lowered minimum,then went up greatly,for which the activity of resistance variety was faster than that of infected variety,as well as became the maximum,which documented that the seedlings of resistance variety were more sensitive against Meloidogyne incongnita... |
