Construction Of SSH CDNA Library Of Purple Sweet Potato Induced By Black Rot And Its ESTs Analysis

Sweet potato is the world’s most important food, feed, industrial raw materials and bio-energy crops, China is the world’s largest sweet potato producing countries. Sweet potato is rich in nutrition. The purple sweet potato is a new variety of sweet potato, its skin is purple, the succulent is purple too. Purple sweet potato in addition to the ordinary sweet potato nutrients, but also rich in selenium and anthocyanins.Black spot is the most common and serious disease on sweet potato in the world. It is caused annual loss of about10%each year in China. Either people or livestock eat sweet potato with black spot will cause poisoning and even death. Suppression subtractive hybridization technology is the most cost-effective method of new gene discovery. The separation and identification of C. fimbriata was completed and SSH cDNA library of purple sweet potato induced by black rot was successfully constructed.The first part of experiment is to isolate the Ceratocystis fimbriata from the sweet potato disease and purified, then identify the resistance to black spot in purple sweet potato. Among20accessions,1varieties are high resistant,4varieties are resistant and15varieties are susceptible.The second part of this study use purple sweet potato No.1for materials, built to black rot induced by12h、24h、36h、48h、60h after the purple sweet potato tuberous roots mixed SSH library. Were randomly picked103clones sequenced. Received a total of87ESTs, including29Contigs and58Singlets. The use of tblastx in the NCBI database sequences homologous to these87ESTs, No.14EST found the resistance of Rose black spot which is muRdrl gene locus, gene sequences, including a total of9 genes muRdr1A, muRdr1B, muRdr1C, muRdr1D, muRdr1E, muRdr1F, muRdr1G, muRdr1H, muRdr1I. In addition there are higher levels of two types of genes, purple sweet potato tissue specificity related genes, and the other is purple sweet potato resistance to drought stress related genes. The suppression subtractive hybridization (SSH) technology to build cDNA library, and use EST technology combined with bioinformatics technology to study the black rot resistant mechanism of purple sweet potato from the genetic level according to expression analysis of related disease resistance genes.