Studies On Natural Hybridization Between Miscanthus Sinensis And M. Floridulus

Penetration of natural hybrid has always been the hottest issue in the field of taxonomy and evolutionary biology, owing to be hindered by the traits of its wide range of origins, frequent occurrences, and difficulties in identifications. Miscanthus is a new type of energy plant, the study of whose classification and evolution need to be improved urgently. It's hard to accurately distinguish a certain plant and identify its taxa by morphological phenotype whose characteristics is similar to and Miscanthus during the collection of wild plants resources. Though research and analysis to different phenotypes and Adh1 gene sequences of, a primary study into genetic and phenotypic penetration between sinensis and miscanthus in the process of the natural hybrid origin. The major results were as follows:1) morphological phenotype analyse.All of 13 materials's 17morphological characters had been determined and analysed.All the morphological characters had been standardized by the ZScores and computed theirs distance. The date operating in the MVSP3.2 by the UPGMA method. The phylogenic analysis based on morphological characters indicated that one putative hybrid (AD431) clustered together with M. floridulus samples and other putative hybrids (AD623,AD512,AD620,AD619 and AD627) grouped with M. sinensis samples.2) Adhl gene analyseAll of 13 materials's Adh1 gene sequence which building-up the phylogenetic trees using the MP method and the NJ method with the other 11 sequences registered in the GeneBank were mensurated and cluster analysed. The results showed that the Adhl gene of the Miscanthus Anderss include 6 exons and 5 introns, and the exon region is 60bp to 210bp,the average value is 114bp. The 19 sequences's region is 1413bp to 1444bp and the average value is 1430bp. The length of sequence is 1473bp when analyse by the ClustalX. The A,T,C,G of the sequence take up 24.7%,30.3%, 20.5%,24.5%,and the sequence has the prominent T predilection, AT(55.0%) greater than CG(45%), and the ratio of between the SI(16) is 1.7two diverged types of Adhl gene sequences presented in all samples of putative hybrids, one of which is clustered with M. sinensis while the other is clustered with M. floridulus on the Adh1 phylogeny, suggesting that they are the true hybrids between M. sinensis and M. floridulus.The phylogenic analysis based on morphological characters can not verification the hybrids, and the Adhl gene sequence analyse can.The Introgressive hybridizationhas been always appears in the nature hybrids, this phenomenon bring about the divergence between two analyse. The heredity background and the morphological characters has been assimilated by the Introgressive of gene and the otherness of the species has been reduced. Acid base of those hybrids's exons and introns has been changed and the exons are more plentifully. The disparate phylogenic controlled by the exons which in the dominant gene is the minority and the neutral mutation can't been expressed in the phylogenic. The otherness of the gene sequence analyse bwtween the morphological characters analyse is familiar, and the sequence analyse is more essential, general, exacting and the results when identifying the hybrids is more exacting.