Evaluate On Germplasm Of Miscanthus And Research On Agronomic Traits

The demand of energy is increasing more and more with the increase of population and development of economy. The consumption of energy is still from the use of fossil fuel as the main resource. The greenhouse gas emission which results from the rising demands of burning fossil fuel is changing the climate now and turns to species extinction. To decline damage of burning fossil fuel to earth people begin to pay more attention to the use of renewable energy resources in the next decades. Biomass as one of the renewables, which can be produced by green plants converting sunlight to plant material through photosynthesis, has become the one of the renewable world’s energy supply. Among the herbaceous plant species, the perennial rhizomatous C4 grass, Miscanthus, has been identified as a good candidate biomass crop with character of high ratio of output and input. Miscanthus crops performed higher water and light energy utilization, and nutrition recycle efficiency. The species Miscanthus × giganteus is widely used in Europe for production. However this species is threaten by freezing injury in winter and cold spell in later spring when widely spread in northern of Europe. M. × giganteus is sterile and reproduced by the rhrizome. Therefore, developing new species, enlarging the diversity to fit the different growth condition is important for breeding purpose.We collected 52 wild individuals of Miscanthus s.l. and Saccharum s.l. species from the distribution of central-south-east in China. Each of wild individual is taken as a clonal accession. These entire samples include M. sinensis, M. sacchariflous, M. floridulus, and Saccharum arunidinaceum. All of the clons were rhizomes collected and propagated in Linan (119°72N,30°23E) of Zhejiang province of China. The polyploid level of the accessions analyzed by the flow cytometer was diploid.21 clons including 3 genotypes:M.×giganteus, M. sinensis and M. sacchariflorus were established at the INRA trials unit in Estrees Mons (49°53 N,3°00 E) of France, More polyploidy level was found in these cultivars:among these 14 diploid (2x=38), 3 triploid (3x=57), and 4 tetraploid (4x=76).We designed primers using the large single copy region of chloroplast from sugarcane which allow us to identify some putative maternal genomes related to the maternal genomes of much of the Miscanthus cultivated clones in Europe. Among the Miscanthus European clones and accessions native from China that we tested, the polymorphisms were substitutions. The phylogenetic relationship among the haplotypes was inferred by statistical parsimony network. We detected high levels of haplotype variations of many Miscanthus among the European cultivars and wild accessions in China and identified maternal genomes related to the progenitors of cultivated species. M. x giganteus had maternal genome identical to wild relatives occurred in the sympatric zone of M. sacchariflorus and M. sinensis. We also defined some regions with diversity haplotype which are Sichuan and Zhejiang province where can be potential genetic sources endemic.We observed and examined cultivars in Estrees-Mons Unit INRA of Northern France and Zhejiang province in China by combining several published approaches to describe the botanical characters of Miscanthus. We were able to distinguish the M. x giganteus from the other species by the presence of axillary buds on the nodes of their stems and awnless. We found M. sacchariflorus by callus hairs more than twofold of the length of spikelet. M. floridulus always construct large panicle and flower early in China. Different from M. floridulus, M. sinensis had axis length between 1/5-1/2 of length of panicle. At the internal genotype level, the spikelet in polyploidy was longer than that in diploid.M. floridulus collected in nature China showed stronger culm and larger tuft diameter, and reached relatively higher biomass during the second season even though it flowers early. It may be a potential apecies for high yield S. arundinaceum and M. sinensis showed a compact tuft and lower yield. Our result indicated that stem diameter and tuft diameter were the main agronomic characters positively related to biomass yield at the first growth season.Application of nitrogen indicated that both of PN and Ci in all sepcies of Miscanthus rose significantly as N application increased. Among the test sepcies M. x giganteus was more affected by N application. The initial slope of response curves of PN to Ci which presents the carboxylation efficiency was promoted by N application in all genotypes. Both stomatal conductance and Ci were increased with increased N supply, indicating that stomatal factors played an important role in increasing PN. PEPC concentrations in all sepcies were significantly enhanced with increasing N levels. Despite rbcL concentrations rose with increased N levels there was not as much as PEPC. It looks like that Miscanthus could markedly regulate N investment into PEPC rather than the Rubisco large subunit under higher N conditions. Bundle sheath leakiness of CO2 was constant at about 0.35 for all N levels. Therefore, N enhanced the photosynthesis of Miscanthus mainly by increased stomatal conductance and PEPC concentration.