Agronomic Traits And Polymorphism Research Of Waxy Gene In Proso Millet (Panicum Miliaceum L.) Of China

As a kind of minor crops, proso millet （Panicum miliaceum L.）, originated from China, is one of the oldest crops, whose grain can be divided into Waxy （glutinous） type and non-Waxy （non-glutinous） type. Own to the improving of the life quality of humanity, more attention is paid on the quality traits of proso millet with the more and more demand on minor crops. China has very rich germplasm resources of proso millet. According to the statistics,8515 varieties have been collected and complied into the china proso millet germplasm resources index. Nonglutinous-glutinous property has always attracted much attention as an important indicator of measuring the palatability of cereal. It’s decided by the kind and content of starch in plant. There are two starch types of amylose and amylopectin and the Waxy phenotype results from mutations in the GBSSI gene, which catalyzes amylose synthesis. Waxy genes control the content and types of starch, so it can both provides theoretical basis and practical significance for improving palatability of proso millet to figure out the corresponding relation between the phenotype of nonglutinous-glutinous property and genotype of Waxy genes and discover the regulation mechanism of Waxy genes.We used the 241 landrace accessions of proso millet from 17 provinces of China in this study, I2-KI staining of starch granules found 107 Waxy phenotype and 134 non-Waxy plants; of which most were Waxy varieties collected from Shanxi province and Heilongjiang province.In order to determine the genotype, we amplified, sequenced and aligned the special fragments of Waxy gene with the designed primers. The result showed the genotype S.15/LFhad the largest proportion for 38%,the genotype S.15/LYhad the minimum proportion for 7% and no genotype S₁5/LC were found. By contrast of genotype and starch phenotype, we found both the combination of S₁5 allele with LF allele and LF allele added to Waxy, while the combination of So allele and LY, Lc and LF leaded to non-Waxy. In addition, we also found out the 12 L-type new sites of SNP mutation. They were the inserted G on the 2113 th site of material 3; G replaced A on the 2170th site of material 12,167,180 and 194; C replaced T on the 1890th site of material 20 and 237; C replaced G on the 2350th site of material 98; C replaced G on the 2230th site of material 109; G replaced C on the 2274th site of material 110; G replaced A on the 894th site of material 167; the inserted T on the 2337th site of material 239.We investigated 10 agronomic traits of 241 corn millet materials and found that the highest coefficient of variation was that plant height reached 2.01 and veins density reached 1.76; the highest genetic diversity index was that 1000-grain weight reached 66.70% and the minimum vein density reached 12.43%. Proso millet resources was analyzed by clustering analysis, can be divided into four groups:the characteristics of the first group were larger spikes, larger leaf area, larger upper and lower epidermis stomatal density difference, heavier grain; The second group were shorter plants, shorter spikes, lower main stem section, lighter grain; The third group were higher plant, larger spikes, more main stem section, larger leaf area, lighter grain;The fourth group were higher plant, more main stem section, lighter grain.