A Simple Method For Rapid Preparation Of Plant Genomic DNA And Improvement Of Starch Quality Via Marker Assisted Selection Methods In Rice (Oryza Sativa L)

With China's rapid development of economic and people's rising living standards in the 21st century, it is necessary for people to improve grain yield and quality. China have been made a big progress of the grain yield study by application of heterosis and dwarfing breeding. But generally, the grain quality is very low, which impact our international competitiveness and the level of people's life seriously. With the rapid development of molecular biology and molecular genetics, the traditional breeding methods have been converts to the molecular makers assisted selection breeding now. Using molecular markers which closely linked with key functional genes, we can get good genes pyramiding and cultivate new varieties with high-quality, high yield andmultiple resistance.9311 also called Yangdao6. It have sturdy stem, strong and high color leaves, better strains of leaf type, good grain quality, stable yield, strong resistance to lodging, good maturing phases, and so on. It is a high quality conventional rice variety cultured by Yangzhou Lixiahe Agricultural Science Institute. Nipponbare is a japonica from Japan. It is a short plant. The grain quality is as good as 9311 and lodging resistance is poor. 9311 is quite different from Nipponbare with amylose content whereas it is no significant difference with gel consistency and gelatinization temperature. According to Blast sequence analysis, we identified 9311 and Nipponbare that completely sequenced and found 18 starch synthesis-related genes with differences. We developed detection marker based on PCR technology. To improve the grain quality of 9311, we use Hybridization, backcrossing and selfing methods and introduce quality-related genes which are different between 9311and Nipponbare into 9311. After 6 times of continuous backcrossing with 9311 and marker-assisted selection, we construct a SSRGs(starch synthesis-related genes) near isogenic lines under the background of 9311. Finally we complete multi-gene aggregation. By transformation of starch branching enzyme (SBE) genes strains we found that all near-isogenic lines were no significant difference with 9311 on most of the agronomic traits. The background of near-isogenic lines is very close to 9311. Starch synthesis genes transformed into Nipponbare can effectively improve amylose content of 9311, because there is not much difference between Nipponbare and 9311 with gel consistency and gelatinization temperature. So the gel consistency and gelatinization temperature have no significant change. Overall, we achieved the purpose of improvement rice quality.