Study On The Clonal Architecture And Clonal Diversity Of Bermudagrass(Cynodon Dactylon (L.) Pers.)

Bermudagrass(Cynodon dactylon(L.)Pers.)belongs to the genus Cynodon,family Gramineae.It is one of the most widely used and highest value grass in warm season turfgrass.This grass could form good quality turf because its stolon has a great extension capacity.Now it could be used in the turf of park,residential area,square,sports field and ecological restoration.In this study,the characteristics of clonal architecture,the biomass,the clonal diversity and the clonal structure based on SSR markers of bermudagrass from three different habitats were studied.These results have significant meanings for further analyzing on the ecological adaptability mechanism.It could also provide scientific basis for developing and utilizing this wild germplasm resources,and constructing and maintaining the turf in different habitats.The results were as follows:(1)The results based on analyzing clonal architecture from different habitas showed that the erect stem density were higher,the erect stem height were lower,the stolon length were longer,the spacer length were shorter,t he branching intensity was bigger and the branching angle was smaller in habitat of sufficient light.However,the characteristics of the components above mentioned showed an opposite trend in habitat of insufficient light.Clonal architecture of the C.dactylon populations tended to be“phalanx” in sample plot A and C,but "gurilla" in sample plot B.(2)The results based on the perspective of biomass showed that the erect stem biomass,stolon biomass,root biomass,aboveground biomass,total biomass and rootshoot ratio of bermudagrass were all in the low level with habitats of insufficient light and trample.The above indicators were relatively high in habitats of better growing conditions.There was significant ecological plasticity in clonal architecture and biomass of bermudagrass population in different habitats.(3)The amplification results showed that 94 bands were amplified from 131 bermudagrass samples of which 86 bands were polymorphic,and the percentage of polymorphic bands was 91.49%.The percentage of polymorphic bands of three samples was sample b(77.17%)> sample a(56.94%)> sample c(27.27%).(4)The results of clonal diversity and clonal structure showed that the clonal diversity of bermudagrass was comparatively high.The mean proportion of distinguishable genotype ratio(PD)was 0.353,and the simpson diversity index(D)was 0.707.The number of base plants and the level of clonal diversity from high to low was sample b > sample a > sample c.(5)The results of genetic diversity were showed that the Nei's genetic diversity index(h)and Shannon 's information index(I)were 0.2993 and 0.4493 respectively which showed that the studied bermudagrass accessions collected from fine-scale scope had comparatively abandon genetic diversity.The level of genetic diversity of three samples from high to low was sample b > sample a > sample c.(6)The results of genetic relationship among 131 bermudagrass accessions were showed these accessions could be divided into two groups based on the results of STRUCTURE,UPGMA and PCoA.The accessions from sample a and b were clusted into one group,and the accessions from sample c were clusted into another group.