Genetic Diversity Of Green Millet In China

Green millet (Setaria viridis) is an annual grass belonging to Setaria, closely related to foxtail millet (Setaria italica). It shows excellent characteristics including resistant to drought, tolerance to poor soil, strong adaptability to various environments, high water usage efficiency. As the green millet resources have a wide distribution and grow in a variety of ecological environment, they are rich germplasm resources containing potentially many excellent genetic resources. Genetic diversity analysis of these resources would promote their exploration, protection and utilization. In this experiment,18morphological indexes were determined and the genetic diversity was analyzed with20pairs of SSR markers among185green millet resources. The main results were as follows:1. Eighteen morphological indexes including plant height, ear length, ear diameter, leaf area, chlorophyll content, stomatal density, grain color, grain shape and etc., of185green millet resources were determined and their diversity analysed. Among these morphological indexes, plant height showed the highest diversity index (2.08) and plant dry weight the lowest (1.49).2. The correlation among10traits was analysed, and22pairs of traits reached significant level with0.01%probability. The ear number and branch number showed the highest correlation coefficients (r=0.96). There were eight pairs of traits showing significant correlation, accounting for5.2%of the total pairs.3. Green millet resource population was analyzed by Hierarchical Cluster Analysis based on18traits. The results showed the green millet resources were classified into six clusters and each group had its own characteristics. The characteristics of the first group were larger spikes, longer bristle, higher stomatal density of upper epidermis and lower vein density than the others. The feature of the second group was that they had larger leaf area. The plants in the third group were taller, more tillers, more biomass, higher stomatal density of lower epidermis. The features of the fourth group were lighter grain, higher vein density. The characteristics of the fifth group were less tillers, branches and panicles, less biomass of whole plant as well as the grain, and higher chlorophyll content. The characteristics of sixth cluster were heavier grain, smaller spikes, shorter bristles, shorter plants, lighter weight of whole plant, smaller leaf area, lower stomatal density and lower chlorophyll contents.4. The genetic diversity of185green foxtail resources was investigated by using20pairs of SSR molecular marker. One hundred and twenty-four allelic variations were detected. B153had the maximum number of alleles, which is10. B269had the highest diversity index, genetic diversity and polymorphic information content, which are1.9437,0.8473and0.8285,respectively.5. Genetic structure analysis of the185green millet showed that they could be classified into4big groups. The result showed that some varieties of green millet from the same region were not classified to the same group, indicating that there is no clear boundary in terms of genetic background among different regions.