Study On Genetic Variation And Interspecific Relationship Of Zoysia Willd.

Zoysia Willd. is charactered with little fertilizer utlization, stress resistance andslow growth. But registration of variety is too slow to meet the need of users. Thegenetic base used in zoysiagrass breeding is very limited now, and to find and usegenetic resources are the key to make progress for breeding. Many good characters inthose species have not been used as turfgrass, we need to make clear about the geneticrelationship of species in Zoysia Willd. for the purpose of using more geneticresources to guide breeding.The morphological, isozyme and SSR three genetic markers in different levelwere used and combined with the geography distributing and interspecific hybridizingtest to study the genetic variation and interspecific relationship of 59 accessions ofZoysia Willd. belonging to 9 species and 1 variety. The results showed as follows:1,With observing and measuring 23 morphological features on accessions ofZoysia Willd., gained results as:①The accessions of Z.matrella(L.)Merr had greatestvariation on most characters, Z.japonica Steud and Z.sinica Hance had greatintraspecies differentiation but smaller than Z.matrella(L.)Merr, and the degree ofgenetic diversity within species of these two were very close. The accessions ofZ.koreana Mez and Z.tenuifolia Thiele had little differentiation on many charactersrespectively, and the genetic diversity of these two were smaller;②The clusteranalyzing results show: All these species can be classified by genetic distance to be 3classes: The first class included of Z.japonica Steud and Z.sinica Hance,Z.koreanaMez and Z.macrostachya Franchet et Sav; the second class included Z.tenuifoliaThiele,Z.matrella(L.)Merr,Z.minima Zotov and Z.sinica var. nipponica Ohwi;Z.macrantha Desvaux was clustered to be a group itself;③The principal componentsanalyzing results show: The width of blades, the length and diameter of stolons, thespikelets number of one spike, the length of spikelets and the pedicels, the height ofprocreant culms, the ligule colour,whether clustered with hairs or not, these featuresare important in researching of the genetic relationship of species.2,Three isozyme systems (MDH,EST,POD) were conducted on 59accessions of Zoysia Willd. to study the genetic relationship of species. The resultsshow as follows:①the genetic diversity was ranked as: Z.matrella(L.)MerrZ.japonica Steud＞Z.sinica Hance＞Z.koreana Mez;②the clustering analysisresults show: Z.japonica Steud and Z.sinica Hance,Z.sinica var. nipponia Ohwi andZ.macrostachya Franchet et Sav were clustered together; Z.matrella(L.)Merr, Z.tenuifolia Thiele were clustered to be a group, then Z.minima Zotov,Z.pacificaHotta,Z.macrantha Desvaux were also clustered to this group; Z.koreana Mez wasclustered to be a group by itself.3,SSR markers were used to study the genetic relationship of materials ofZoysia Willd..①The genetic diversity within species ranked as: Z.japonica Steud,Z.sinica Hance＞Z.koreana Mez＞Z.matrella(L.)Merr;②Z.japonica Steud wasclustered together with Z.sinica Hance,Z.macrostachya Franchet et Sav andZ.koreana Mez; Z.matrella(L.)Merr was clustered together with Z.tenuifolia Thieleand Z.minima Zotov; Z.macrantha Desvaux and Z.sinica var. nipponica Ohwi was agroup by itself respectively.4,According to three genetic markers and combining with geographydistributing and interspecific hybridizing test, the genetic relationship of 9 species and1 variety showed follows: Z.japonica Steud and Z.sinica Hance were closest indendrograms, and the genetic relationship was closest. The relationship betweenZ.macrostachya Franchet et Sav and Z.japonica Steud,Z.sinica Hance was close.Z.matrella(L.)Merr and Z.tenuifolia Thiele were together in dendrograms, Z.minimaZotov had close relationship with these two. Z.macrantha Desvaux was far off thoseother species. Z.koreana Mez was close with Z.japonica Steud and Z.sinica Hanceaccording to morphological and SSR markers and was consistent with the geographydistributing and interspecific hybridizing test, although different from result obtainedfrom isozyme marker. Z.sinica var. nipponica Ohwi was in different position in threedendrograms. Z.paciftca Hotta was clustered together with Z.matrella(L.)Merr,Z.tenuifolia Thiele and Z.minima Zotov according with isozyme markers, and notanalyzed in other two markers.5,The genetic diversity within species was ranked as Z.japonica Steud,Z.sinica Hance＞Z.koreana Mez according to three genetic markers.The degree ofgenetic diversity within species of Z.sinica Hance and Z.japonica Steud were veryclose.The intraspecies differentiation of Z.matrella(L.)Merr was very great accordingto morphological and isozyme markers, but small in the study of SSR marker.