Discovery For Pleioblastus Germplasm

Pleioblastus has important economic,ecological,cultural and social values.It includes tall bamboo species used to produce timber and bamboo shoots,which mainly grows in China,and also dwarf green ornamental bamboo species which is mainly produced in Japan.However the germplasm resources of Pleioblastus and its related species hasn’t been detailed studied and researched yet.We conducted extensive sampling from model producing areas,main producing areas,and distribution areas,investigated the phenotypic traits of Pleioblastus and its related species deeply and systematically,proposed the description traits of Pleioblastus’s germplas,and excavated some excellent germplasms resources.Based on NCBI molecular data,we developed some SSR obligate primers of Pleioblastus,and executed the molecular identification research on the pleioblastus germplasms we collected.Also we carried out photosynthetic physio-ecological measurements and comparisons on main species of Pleioblastus,found and firstly described the flowering properties of Pl.yixingensi.All of our studies will provide data and materials for further germplasm collection and excavation of Pleioblastus.The main results we obtained are as follows:1.Through extensive sampling of the distribution areas of Pleioblastus,especially the survey of plant traits in model producing areas,we performed a systematic study on phenotypic traits of Pleioblastus’s germplasm,combed the economic traits of Pleioblastus species,and established the DUS descriptors standard（draft）for Pleioblastus’s germplasm resources.49germplasm test traits like stalk height and so on were determined,including 13 quality traits such as internodes shape,21 quantity traits such as the length of the section,and 15 pseudo quality traits such as new culm color.2.There were 587 nucleotide sequences of Pleioblastus downloaded from NCBI which were processed by MISA software package,and 404 non-redundant sequences were obtained,of which the total length was 247420 bp.Altogether 45 SSR-containing sequences and 47 SSR locus were detected.The frequency of occurrence was 1.14%,and all SSRs were of the single nucleotide repeat type.And 6 pairs of obligate primers were successfully designed,primers with clear bands and stable amplification results were selected which were firstly filtered by agarose gel electrophoresis,These primers were used to compose forward fluorescent labeled primers with5’-end FAM-labeled,and processed by capillary electrophoresis.The results showed that the designed 6 pairs of dedicated primers were all polymorphic while only 3 pairs of the 26 pairs of primers selected from literature were polymorphic.In general,SSR primers selected from reference were less versatile in identifying the germplasm of Pleioblastus than obligate primers.3.These polymorphic primers were used to detect the 62 samples of Pleioblastus’s germplasm resources.A total of 37 alleles were detected.On average,4.1111 alleles were detected for per pair of primers,among which 7 alleles were the most.Based on the 9 primers and 6 obligate primers of Plieioblastus respectively,use the software NTSYS to calculate the genetic similarity coefficient among the germplasms and perform cluster analysis according to the UPGMA method.Results showed that,with the similarity coefficient of 0.655,62germplasm materials were divided into 8 categories.Basically the 2 categories division which are domestic Pleioblastus and Japanese Pleioblastus were supported,which shows that they have a unique origin respectively.Also,3new germplasms were individually gathered into categories,which had close relationship with Pleioblastus amarus,demonstrating its Pleioblastus identity.4.There were 10 accession of Pl.maculatus which are the most widely distributed Pleioblastus bamboo collected from Sichuan,Chongqing,Hubei,Hunan all gathered,and Pl.yixingensis collected from Zhejiang,Jiangsu,Anhui,and Henan also gathered,thus their genetic stability and consistency were demonstrated.Pl.kongosanensis was moved into Sasaella Makino due to the observed number of 6 stamens,but SSR molecular identification supports that it is more reasonable to keep Pl.kongosanensis in Pleioblastus.The reasons still needed to be studed.5.Performed photosynthetic physioecological analysis on main Pleioblastus species,and the right angle hyperbola was most suitable for Pleioblastus.8 species’photosynthetic-light response curves were intensity-suppressed type,and 6 species photosynthetic-light response curves were saturation approaching type.The light compensation points are all lower than20μmol·m^-2·s^-1.And except two bamboo’s light saturation point can reach around2000μmol·m^-2·s^-1,for the other species,the light saturation points are all below1200μmol·m^-2·s^-1.The effective photosynthetic radiations are between 3-14μmol·m^-2·s^-1.All the studies of above showed that Pleioblastus is a shade-tolerance bamboo species.This could be an important reference for Pleioblastus introduction,cultivation and undergrowth planting.At the same time,we also found that the chlorophyll fluorescence parameters of the Pleioblastus are generally low,such as Fv/Fm,Fv/Fo,NPQ,qP,ΦPSII,and ETR,indicating that photosynthesis of the Pleioblastus is under stress from environment.6.We discovered synchronously the flowering phenomenon of Pl.yixingensis in April2017 in the areas of Henan,Zhejiang,Jiangsu,and Anhui.The number of stamens of Pl.yixingensis was found 3,4,5,6,with 3 being dominant.And the results of SSR molecular indicated that all the Pl.yixingensis were gathered and closed to the Pl.amarus,thus it may not be appropriate to be renamed Acidosasa yixinggensis.The pollen of Pl.yixingensis was light-stained abortion.Its pollen germination rate was only 5.11%,and the seed setting rate was less than 10%.