PHYLOGENETIC-RELATIONSHIPS OF TURFGRASSES AS REVEALED BY RESTRICTION FRAGMENT ANALYSIS OF CHLOROPLAST DNA

Chloroplast DNAs (cpDNAs) were analyzed in order to clarify the phylog enetic relationships among turfgrasses. Physical maps of cpDNAs from A grostis stolonifera and Zoysiajaponica, which are representative speci es of cool (C3 type) and warm (C4 type) season turfgrasses, respective ly, were constructed with four restriction enzymes, i.e., PstI, SalI, SacI, and XhoI. The genome structures of these cpDNAs were found to be similar to each other in terms of genome size and gene orders, showin g thereby a similarity to other grass cpDNAs. CpDNAs of 5 species of c ool season turfgrasses and 6 species of warm season turfgrasses as wel l as four species of cereals, distributed among 14 genera of Gramineae , were digested with PstI, XhoI, and BamHI, and their restriction frag ment patterns were compared. Their genome sizes were estimated to be 1 35-140 kbp. Each species showed characteristic RFLP patterns. On the b asis of the frequency of commonly shared fragments, a dendrogram showi ng the phylogenetic relationships among their cpDNAs was constructed. This dendrogram shows that turfgrasses can be divided into three major groups; these correspond to the subfamilies. Cool and warm season tur fgrasses are clearly distinguishable from each other, and the latter c an be further classified into two subgroups that correspond to Eragros toideae and Panicoideae. Our classification of turfgrasses and cereals by RFLP analysis of cpDNA agreed in principal with their conventional taxonomy, except for the location of Festuca and Lolium.