The Content Determination Of Oat Starch, And Granules Bound Starch Synthase Gene(GBSS Ⅰ) Sequences Cloning

Oat (Avena L.) belonging to Aveneae, Pooideae, it is one of the eight major food crops. With strong resistance to cold, drought, barren and salt alkalescence and doesn’t compete with rice or wheat for farmland. Therefore, it has the advantages of low agricultural risk coefficient, which is a special kind of crop. Development of oat planting and processing is great significance for promoting the sustainable development of agriculture. Starch is a part of the oats mainly be used as food by human, including amylose and amylopectin. Previous studies have shown that GBSSI gene plays an important role in deciding on the waxy trait of starch. Starch is directly related to the quality and application prospect of crop, and the content level is meaningful for quality assessment of Oat, which has practical significance for guiding seed selection and breeding. In this study, we provide some oats for the determination of starch content and the DNA fragment analysis of the main function gene, evaluation the starch content of Avena species and the proportion of amylose and amylopectin, discussion the referenced value for production and subsistence. Based on the GBSSI gene fragment to provide new phylogeny evidence of genus Avena, and to find the correlation between the amplification gene fragments and starch content.The main results are summaried as follows:1) The contents of amylose and amylopectin in the 107 populations of oat from all over the world (25 species) are determinde by dual wavelength spectrophotometry. The result showed that starch contents has significant difference from different population. Analysis of the frequency distributionthe of amylose and amylopectin content in 107 populations showed that amylose content was 5%～10% frequency distribution, amylopectin content was 45%～50% frequency distribution, In particular that it is found that the chosen material is no amylose content which is between 15%～20% of oat species. According to general situation of grain endosperm starch, amylose content is close to zero, which is less than 1% of waxy. Amylose content of a sample belongs to A. agadiriana (Accession number:CN25869) is 0.7%, which should be a natural waxy species, and the samples which belong to the species A. agadiriana (CN25863), A. clauda (CN21388) and A. hirtula (CN22633) respectively, are lower amylose content. The overall analysis showed that there are four oat species contain low amylose content, A. clauda, A. hirtula, A. eriantha and A. agadiriana. Compared the different Avena genome, Cp genome is the lowest amylose contents, and the amylose contents of all hexaploid samples are generally higher than 8%.2) There are 165 kinds gene fragments of GBSSI of 52 Avena samples have been amplified. The most representative 82 GBSSI gene sequences were selected for analysis after comparison. Alignemnt results showes that there is various variation for GBSSI gene sequences in the genus Avena between different species. The differences within the population performance is different in different species:A diploid genome is basically a single copy, while C diploid genome type more copies, it is different from the single copy conclusion by previous GBSSI genes experimental for wheat, barley and other gramineous crops.3) The results of multiple sequence alignment concluded that the GBSSI gene sequence variation of C diploid genome is more obvious than A genome. In addition, one sequence of the C genome species A. clauda shows more nearly related with A genome than C genome, speculated that the species genotype may be in the position of the between A and C genome, which is in a special position in the genome evolution, and plays an important role. For the tetraploid species, AB genome species A. barbatain are close related with A genome species A. hirtula. Moreover, AC genome tetraploid A. murphyi have close phylogenetic relationship to diploid species A. hispanica. While hexaploid species A. fatua have shown a close genetic relationship among the two groups of the diploid species, A. hirtula/A.lusitanica, and A.hirtula/A.atlantica, respectively.4) Based on previous studies, we try to find the relationship between genetic sequences and amylose content. Amy lose contentin of diploid genome A is higher than that in diploid C genome, and diploid exons fragment had a regular single-base differences at the 30th base in the fragment of this study. But because oat diploid have significant difference between A and C genome, so we still cannot determine the associations of this gene fragments with amylose content.