早熟禾种质资源及其遗传改良研究进展

 对国内外早熟禾种质资源概况、资源利用与评价、生物学特性、资源遗传改良及生物技术应用进展等进行了系统综述，并对目前存在的主要问题及如何解决提出相应的策略。早熟禾资源在中国蕴藏量极为丰富，其中有许多种类已成为世界公认的优良冷季型草坪草。草地早熟禾(Poa pratensis L.)是应用最多的草坪草，美国等注册的大量改良品种占据着世界种业市场；加拿大早熟禾(P. compressa L.)、糙茎早熟禾(P. trivialis L.)及一年生早熟禾(P. annua L.)可作为固土护坡等生态环保特殊用途的草种。国内对引进资源的研究主要集中在抗性生态适应和观赏性评价上，并编制了新品种培育的国内规范标准。目前对早熟禾资源研究的热点是围绕早熟禾特殊的兼性无融合生殖方式进行基础研究和生物技术改良，认为多倍体无融合品种受多源显性等位基因控制，通过组培和转基因手段对获得的再生体系进行改良取得了显著成就，但应加强转基因植株的应用研究及国有资源的基础研究和开发。

Advances in Studies on Germplasm Evaluation and Genetic Improvement of Genus Poa

A diverse germplasm of the genus Poa exists in China, and some species of the genus are known worldwide as good, cool-season turf grass, which thus attracts wide attention, both domestically and abroad, for their potential utilization.This paper reviews in depth the general aspects of Poa germplasm introduction, germplasm resource evaluation and utilization, biological characteristics, genetic improvements of germplasm, and applications of biotechnology in plant breeding; it also proposes some strategies to be used in dealing with some problems encountered. Poa pratensis L. is the most widely used turf grass, with American varieties dominating the world seed market; P. compressa L., P. trivialis L. and P. annus L. each can be potentially used as grass species for soil conservation and slope protection. Past researches in China focused on resistances to biotic stresses, ecological adaptations, and ornamental evaluation of those introductions; and on the basis, criteria of selective breeding for new varieties for China domestic uses have been compiled as references. At present, major research interests of Poa are its peculiar facultative apomixes - its mechanisms and biotechnological improvements. Polyploidy apomixes are reported to be controlled by multi-pairs of dominant genes. Some achievements have been made on genetic improvements of regenerated plants derived from tissue cultures and transgenic approaches. It is viewed, however, that applied researches on transgenic plants and basic researches on domestic germplasm resources be emphasized.