Yaneshita M, Nagasawa R, Engelke M C, Sasakuma T
Japan Turfgrass Inc., Chiba, Japan.
Genes Genet Syst. 1997 Aug;72(4):173-9. doi: 10.1266/ggs.72.173.
Genetic variations among 17 accessions of zoysiagrasses collected from natural populations in Japan were investigated by RFLP analyses of chloroplast DNA (cpDNA) and nuclear DNA. These accessions were classified into five species based on morphological characteristics: Zoysia japonica, Z. matrella, Z. tenuifolia, Z. sinica, and Z. macrostachya. On the basis of eight kinds of RFLPs in cpDNAs detected across accessions, six chloroplast genome types (types A-F) were identified. Although type-A cpDNA was shared by five accessions of japonica and four accessions of matrella, derivative cpDNAs of type A, which each arose by a mutation, were identified in one accession of japonica (type B) and in two accessions of matrella (type C). One accession of japonica which showed spikelets similar to those of shapes macrostachya, contained type-F cpDNA as did sinica and macrostachya. The two accessions of tenuifolia each showed a specific cpDNA type, i.e. types D and E. Genetic relationships among the 17 accessions were investigated by the RFLP analyses of nuclear DNA with 20 genomic and gene probes. A dendrogram constructed with genetic distances calculated from the RFLP patterns indicated four major groups among them. Six accessions of japonica comprised one group, whereas the one accession of japonica possessing the type-F cpDNA was clustered with macrostachya and sinica. Four accessions of matrella with type A cpDNA constituted another group in the dendrogram, showing a closer relationship to the japonica accessions than to the other two accessions of matrella. The remaining two accessions of matrella and tenuifolia accessions were grouped together. These data indicate that zoysiagrasses distributed in Japan harbor highly genetic variations, and that interspecific hybridization has occurred in natural populations.
通过对叶绿体DNA（cpDNA）和核DNA的限制性片段长度多态性（RFLP）分析，研究了从日本自然种群中收集的17份结缕草材料的遗传变异。根据形态特征，这些材料被分为五个物种：日本结缕草、沟叶结缕草、细叶结缕草、中华结缕草和大穗结缕草。基于在各材料中检测到的cpDNA中的八种RFLP，鉴定出六种叶绿体基因组类型（A - F型）。虽然A - F型cpDNA由五个日本结缕草材料和四个沟叶结缕草材料共享，但在一个日本结缕草材料（B型）和两个沟叶结缕草材料（C型）中鉴定出了由突变产生的A - F型cpDNA的衍生cpDNA。一个日本结缕草材料的小穗形态与大穗结缕草相似，其含有与中华结缕草和大穗结缕草相同的F型cpDNA。两份细叶结缕草材料各显示出一种特定的cpDNA类型，即D型和E型。利用20个基因组和基因探针通过核DNA的RFLP分析研究了这17份材料之间的遗传关系。根据RFLP图谱计算的遗传距离构建的树状图表明它们分为四个主要类群。六个日本结缕草材料组成一个类群，而具有F型cpDNA的一个日本结缕草材料与大穗结缕草和中华结缕草聚类在一起。在树状图中，四个具有A - F型cpDNA的沟叶结缕草材料构成另一个类群，与日本结缕草材料的关系比与另外两个沟叶结缕草材料的关系更密切。其余两个沟叶结缕草材料和细叶结缕草材料归为一组。这些数据表明，分布在日本的结缕草具有高度的遗传变异，并且在自然种群中发生了种间杂交。
