Ploidy Level And DNA Content Of Erianthus Arundinaceus As Determined By Flow Cytometry And The Association With Biological Characteristics

In recent years,the development and utilization of biomass energy has attracted more and more researchers' attention all over the world.With the advent of biorefinery technologies enabling plant biomass to be processed into biofuel,many researchers set out to study of improving biomass energy crops Erianthus arundinaceus is not only the potential energy plants,but also an important germplasm resources of sugarcane breeding.In order to use the resources reasonably,we should better determine the ploidy level and DNA content in advance.China owes abundant E.arundinaceus resources,in the 1980s,the chromosome of E.arundinaceus was analysed for the first time.Some researches has made karyotyping analysis,found that E.arundinaceus chromosome owe three types,including 2n=20,40 and 60,2n=20 and 2n=40 types are few,mainly distributed in Tibet and Guizhou et..Although the ploidy level of E.arundinaceus have been determined in advance,the existing data are limited to a few cultivars.DNA content reflects entire and specific genetic information in all biological species.Determination of DNA content of species,not only has important meaning to the research on the species of molecular genetics and cell genetics,but also provides the basic data for the research and genetic evolution of plant genomics.In contrast,the research about the DNA content of E.arundinaceus has not been reported.The objective of this study was to determine the ploidy level and DNA content of the 55 E.arundinaceus accessions using flow cytometry and find the correlation between ploidy and traits.The research has determined the ploidy level of 55 E.arundinaceus accessions.What it showed that among the 55 accessions,four tetraploids and 51 hexaploids were identified.These tetraploids originated from Yunnan Mengma,Yunnan Shuangjiang,Guangdong Gaozhou and Sichuan Chengle.The mean DNA content was 4.820 pg/2C for the tetraploid and 7.300 pg/2C for the hexaploid.Hexaploid were identified with DNA content ranging from 6.730 to 8.391 pg,tetraploids were identified with DNA content ranging from 4.735 to 4.937 pg.Depending on the 12 traits of 55 accessions making use of cluster analysis.What it showed that groups were not simple corresponding to each collection places,but the results still had certain regionalism.In addition,although the tetraploid materials and hexaploids were not simple and direct clustered into two categories,it was obvious that the results still had certain polymerizability.The research has found the correlation between ploidy,DNA content and traits.It showed that the ploidy was negatively correlated with cellulose content,and positively correlated with plant height,stem diameter,leaf width,dry weight per plant,fresh weight per plant and hemicellulose content,but not leaf length,tiller number and ratio of dry weight and fresh weight.The DNA content was negatively correlated with cellulose content,too.But only positively correlated with plant height,stem diameter,leaf width and hemicellulose content,but not other traits.In summary,Among 55 accessions,only four tetraploids were identified,they could complicate research results when choosing and using natural populations,as well as provide important information for breeding of sugarcane.Result of cluster analysis confirmed that the polidy level was correlated with its overall traits.The main target of assessing the correlation between ploidy and traits was to quantify the impact of ploidy level,which provide important information for marker trait analysis,cultivar improvement and breeding of sugarcane in the future.