Study On The Resistance Of Hevein And Ascorbate Peroxidase Double Gen Sisal To Phytophthora Nicotianae

Sisal is the most important economic crops in world,and it has extensive use,comprehensive high value and broad prospects.However,zebra disease is one of the most serious diseases that affect the sisal production and planting.The phytophthora nicotianae is an infectious bacteria,which will lead to infested plants and eventually result in a considerable reduction in production of sisal.As a result,the sustainable development of sisal industry is seriously restricted,which will cause huge economic losses.Therefore,this study is to improve the disease resistance of H.11648,and carried out the following research:1.The double gene expression vector of APX gene and hevein-like started by Hrs203J35S of pathogen-inducible promoter was constructed based on pCAMBIA1300,pCAMIBA1300-Hr203J-Hevein-NOS-Hr203J-APX-NOS.The double gene expression vector was transferred into Agrobacterium tumefaciens EHA105 by freezing thawing method.2.The rDNA-ITS sequence analysis was performed on 14 strains of pathogenic bacteria of zebra diseases collected from Guangdong and Guangxi.The results showed that all of them were phytophthora nicotianae and there was a certain relationship between the rDNA-ITS group and gegraphical rgeions.According to the analysis of the pathogenicity of 14 strains,it was found that there was no direct relationship between the pathogenicity and the region.Two strains of Phytophthora nicotianae that have relatively strong pathogenicity were screened out.3.The plant expression vector pCAMIBA1300-Hr203J-Hevein-NOS-Hr203J-APX-NOS was used as genetic transformation of 122 sisal callus by Agrobacterium mediated method.9 strains of sisal resistant plants were obtained,and the conversion rate was about 7.4%.The PCR and RT-PCR detection of the obtained resistant sisal seedling showed that the 4 strains of sisal seedling were positive,which suggested that the APX gene and hevein-like were successfully transferred into the genome of sisal,and the positive conversion rate was 44.4%.Two strains that have relatively strong pathogenicity were inoculated on the leaves of 4 positive transgenic plants.The results showed that the disease resistance of No.2 transgenic seedling is level 2,the disease resistance of No.1,3,4 was medium,and they were level 3.