禾本科虎尾草亚科细胞学研究分析

Cytological Studies in the Chloridoideae (Poaceae):a Review

总结了虎尾草亚科72属601个分类单位的细胞学资料。虎尾草亚科的染色体基数是10和9,来源于原始染色体基数6经非整倍性减少为5,再经多倍化及非整倍性减少而来。细胞学性状对虎尾草亚科属上类群的分类具有相当重要的价值。推测染色体基数演化的趋势为:x=6→x=5→x=10→x=9。据认为,虎尾草亚科的原始染色体基数为5的二倍体类群在演化早期就灭绝了。

Recent researches on basic chromosome numbers of 601 taxa including 72 genera of the subfamily Chloridoideae are reviewed. Two main basic chromosome numbers occur in the majority of chloridoid genera, i.e. 9 and 10. Evidence indicates that x=9 and 10 are palepolyploid and aneuploid deviation basic chromosome numbers. Cytological characters have significant systematic value in recognizing supra-generic group in the Chloridoideae. An evolutionary trend of basic chromosome numbers is proposed： x=6→x=5→x=10→x=9. The primitive diploid group with 2n=2x=lO might have been extinct in the early, evolution.