菰属系统与演化研究——孕花外稃表皮微形态

应用扫描电子显微镜对禾本科菰属及其有关9属14种3变种1变型的孕花外稃顶端及其芒基部的表皮微形态进行观察比较研究。研究结果基本符合E.E.Terrell与W.P.Wergin的研究报道,但我们不仅种类收集齐全而且增加研究了与菰属有关的属种,及菰属下的一些变种及混淆种,更有利于探讨菰属的系统位置及其演化关系。菰属以其稻型的双胞微毛与硅质体应隶属于稻族。又根据它们所具硅质体形状及硅质乳突的数量,除揭示它为单性花一支与稻属、假稻属、水禾属等两性花一支在稻族中存在平行演化现象外,也揭示了在菰属中共有4种、2亚种,其中以菰最为原始。

A SYSTEMATIC AND EVOLUTIONARY STUDY OF ZIZANIA L. (GRAMINEAE)-EPIDERMAL FEATURES OF PISTILLATE LEMMA

The epidermal features of apex of pistillate lemma connected with its basic part of awn in all species of Zizania L. and its related species were studied by SEM. According to the characters of silica bodies, siliceous papillae etc., the results are summarized as follows:1.Genus Zizania should belong to tribe Oryzeae in Gramineae, by its Oryza type of microhairs and silica bodies.2.The phylogenetic evidence of epidermis features of pistillate lemma indicates that from many siliceous papillae (two perennial species of Zizania and gen. Oryza, Leersia, Luzoila) to few and without siliceous papillae (two annual species of Zizania and gen. Chikusichloa, Hyqroryza etc.) is the evolutionary tread of these taxa, of which gen. Zizania may derived from the same ancient stock with gen. Oryza and can be ascribed to parallel evolution in Oryzeae, i.e. one from perennial species to annual species in gen. Zizania (spikelets monoecious), the another from gen. Oryza to Chikusichloa, Hyqrorgza etc. (spikelets bisexual).3.Zizania mezii is similar to Z. latifolia in this research. According to the priority of International Code, the former species should be as synonym under the latter.4.According to the shape of silica bodies, prickle hairs, microhairs etc. of Zizania L., there are 4 species and 2 subspecies in the world, i.e. Z. latifolia (Gri-seb.) Turcz. ex Stapf, Z. fexana Hitchc., Z. aquatica subsp. aquaiica, Z. palustris subsp. palustris, Z. aquatica subsp. brevis (Fassett) S. L. Chen, Z. palustris subsp. interior (Fassett) S.L. Chen.