| Miscanthus Anderss are tall perennial C4-type grasses in Poaceae, having considerable potential as a biomass crop for renewable energy production. In this study, the chromosome ploidy levels, karytypes and genome size of M. sacchariflorus, M. lutarioriparius, M. floridulus and M.sisensis from the China Mainland had been analyzed by the root tip squashing method and flow cytometry. The study might provide cytological evidences for further revealing the evolution and genetic relationships between species. The main results are as follows:The karyotypes of Miscanthus species were analyzed, including8varieties of M. sacchariflorus,6varieties of M. lutarioriparius,5varieties of M. floridulus and4varieties of M. sisensis. The karyotype formula of M. sacchariflorus was2n=2x=38=30m+8sm from Mudan city of Heilongjiang province, LuochuanShanxi, Ningxian Gansu, Changzhi Shanxi, Xuzhou Jiangsu, and2n=2x=38=28m+10sm for Dalian Liaoning and Fusong Jilin; the formula of population from Rizhao Shandong was2n=3x=57=45m+12sm; The karyotype formula of M. lutarioriparius population was2n=2x=38=28m+10sm, and2n=4x=76=60m+16sm in Nanjing, Jiangsu province; In M. floridulus, the karyotype formula was2n=2x=38=30m+8sm in Hongan Hubei, Xiushui Jiangxi, Datian Fujian, and2n=2x=38=28m+10sm for Longyou Zhejiang and Jinxiu Guangxi; In M. sisensis, the karyotype formula was2n=2x=38=30m+8sm from Chenzhou Hunan, Xinyang Henan, Boluo Guangdong, and2n=2x=38=28m+10sm for Jinxiu Guangxi. The results showed that the chromosomes in4species of Miscanthus were the central centromere chromosome and near the middle centromere chromosome, which was unsymmetrial type.The flow cytometry was used to determin the chromosome ploidy levels of Miscanthus species in China. The results showed that the rest were diploids in the populations comprising of68M. floridulus,39M. sacchariflorus,31M. sisensis,19M. lutarioriparius, except for7triploids in M. sacchariflorus, a triploid in M. sisensis, a tetraploid and a triploid in M. lutarioriparius. Therefore the most of Miscanthus in China is diploid.Using Nipponbare with a known genome size0.90±0.02pg as control, the nuclear genome size of4species of Miscanthus was determined by flow cytometry. The results showed that the average genome size (2C DNA) of M. sacchariflorus was4.51±0.18pg; M. lutarioriparius was4.59±0.18pg; the M. floridulus was5.31±0.15pg; M. sisensis was5.47±0.15pg.The Miscanthus has a greater genome. |
