摘要:草地早熟禾（Poa pratensis）是典型的根茎型禾草，根茎作为其营养物质储藏和营养繁殖的重要器官，在提高植株地表侵占能力及地下固土能力方面具有重要作用。根茎的发生和发育与内源激素密切相关，本试验以采自甘肃境内9个不同生态型的野生草地早熟禾为试验材料，以‘午夜Ⅱ’草地早熟禾为对照，分析根茎扩展能力与内源激素含量间的相关性，以期揭示草地早熟禾根茎扩展的激素调控机理，为草地早熟禾新品种选育和草坪养护管理提供理论和实践依据。结果表明：1）不同生态型野生草地早熟禾根茎扩展能力存在显著差异，榆中草地早熟禾的分蘖数、根茎数、地上生物量和茎节长最大；西和草地早熟禾的覆盖面积、最长根茎和根茎生物量表现最优，供试不同生态型草地早熟禾材料根茎综合扩展能力由强到弱依次为榆中>西和> ‘午夜Ⅱ’ >渭源>灵台>清水>肃南>秦州>夏河>安定。2）内源激素在草地早熟禾根茎和茎基的分布存在差异，GA3、IAA和ABA含量均为根茎>茎基，ZT含量为茎基>根茎，且两个部位GA3含量均高于其余激素。3）相关性分析显示，草地早熟禾根茎扩展能力与ZT含量、茎基ZT/ABA和IAA/ABA极显著正相关（P < 0.01），与根茎GA3/IAA显著负相关（P < 0.05），与IAA、GA3和ABA含量相关性不显著（P>0.05）。综上，榆中草地早熟禾根茎扩展性最强，且优于‘午夜Ⅱ’草地早熟禾（对照），可作为扩展能力强草地早熟禾新品种选育的优良材料；ZT含量和IAA/ABA与ZT/ABA的比值越高，GA3/IAA比值越低，越有利于草地早熟禾根茎扩展。
关键词:草地早熟禾/
生态型/
根茎/
扩展能力/
内源激素
Abstract:Poa pratensis is a typical rhizome grass, of which rhizome is an important organ for nutrient storage and vegetative reproduction that plays an important role in improving plant surface invasion and underground soil consolidation. The occurrence and development of rhizomes are closely related to endogenous hormones. This study investigated the hormone regulation mechanism of rhizome expansion by examining the correlation between the rhizome expansion ability and endogenous hormones contents in nine ecotypes of wild P. pratensis from different areas of Gansu Province and 'Midnight Ⅱ' P. pratensis (the control). The purpose of this study was to provide a theoretical and practical basis for new variety breeding and lawn maintenance and management of P. pratensis. The results indicated that: 1) there were differences in the rhizome expansion ability among the wild P. pratensis ecotypes. P. pratensis from Yuzhong had the largest tiller number, rhizome number, aboveground biomass, and stem node length, whereas P. pratensis from Xihe had the largest coverage area, longest rhizome, and highest rhizome biomass. The rhizome expansion ability of P. pratensis from strong to weak was P. pratensis from Yuzhong > from Xihe > from 'Midnight Ⅱ' > from Weiyuan > from Lingtai > from Qingshui > from Sunan > from Qinzhou > from Xiahe > from Anding. 2) The distribution of endogenous hormones in the rhizome and stem base of P. pratensis was significantly different; the gibberellic acid (GA3), indole-3-acetic acid (IAA), and abscisic acid (ABA) contents were rhizome > stem base; the zeatin (ZT) content was stem base > rhizome; and the GA3 content in the two parts was significantly higher than that of the other hormones. 3) Correlation analysis showed that the rhizome expansion ability of P. pratensis was positively correlated with the ZT content, stem base ZT/ABA, and IAA/ABA (P < 0.05) but negatively correlated with rhizome GA3/IAA (P < 0.05). However, there were no correlations between the IAA, GA3, and ABA contents. In summary, P. pratensis from Yuzhong, which has better rhizome expansion ability than 'Midnight Ⅱ', is good for variety breeding; the higher ZT content and ratio of IAA/ABA to ZT/ABA and the lower GA3/IAA ratio are beneficial to the rhizome expansion.
Key words:Poa pratensis/
Ecological type/
Rhizome/
Expansion ability/
Endogenous hormones
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