Abstract:

Three commercial kentucky bluegrass varieties (Midnight Ⅱ, Baron, Kentucky) were selected to detect the changes of IAA, ZR and ZT contents by high performance liquid chromatography (HPLC) during tillering period. The relationships between the content of endogenous hormone and the tillering ability of kentucky bluegrass were investigated to evaluate the tillering ability of different varieties and provide theoretical guidance and reference for the selection of suitable grasses and management of turf during establishing high-quality cool season turf. The results showed that the variations of IAA and ZR+Z in three varieties were similar during tillering period. The IAA contents of tested varieties reached the maximum (120 ng·g^-1) after germination for one week and then decreased with growing. The ZR+Z contents of tested varieties increased with growing, reached the maximum in 35 d after germination (Midnight Ⅱ 205.82 ng·g^-1, Baron 146.67 ng·g^-1, and Kentucky 172.16 ng·g^-1), and then decreased. The IAA/(ZR+Z) ratios decreased initially and then increased. During kentucky bluegrass tillering, the average number of tiller showed an increase-decrease trend. The number of tiller was negatively related with the content of IAA and was positively related with the content of ZR+Z. The tillering abilities of different varieties were different. The average tillering number of Midnight Ⅱ was greater than Baron and Kentucky, and reached the maximum in 35 days after germination (Midnight Ⅱ 2.45 plant·tiller^-1, and Baron 2.15 plant·tiller^-1, Kentucky 1.98 plant·tiller^-1). Therefore, the tillering abilities of the three varieties ranked in an order of Midnight Ⅱ >Baron >Kentucky.

Key words: Kentucky bluegrass, Tillering, Endogenous hormone, Average number of tillering

摘要：

以商用草地早熟禾(Poa pratensis)(‘午夜2号’、‘巴润’、‘肯塔基’)为材料,采用高效液相色谱法(HPLC)测定其分蘖期间内源激素(IAA,ZR+Z)含量的变化特征,为选择适宜的草种和科学地管理草坪提供理论指导和参考依据.结果表明:在草地早熟禾分蘖过程中, IAA与ZR+Z变化趋势相似,呈单峰曲线,发芽后1周左右,IAA含量达到最大值(120 ng·g^-1左右),此后随着生长时间的增长而减小;ZR+Z含量随着生长时间的增长而升高,在发芽后35 d达到峰值(‘午夜2号’205.82 ng·g^-1、‘巴润’146.67 ng·g^-1、‘肯塔基’172.16 ng·g^-1),此后下降;IAA/(ZR+Z)比值呈先下降后上升的变化趋势.草地早熟禾分蘖期间,草地早熟禾平均分蘖数呈先上升后下降趋势,其平均分蘖数与IAA含量成负相关,与ZR+Z含量成正相关.就不同品种分蘖能力而言,‘午夜2号’平均分蘖数均大于‘巴润’和‘肯塔基’,且在发芽后第35 d左右达到最大值 (‘午夜2号’2.45分蘖枝·株^-1,‘巴润’2.15分蘖枝·株^-1,‘肯塔基’1.98分蘖枝·株^-1).表明‘午夜2号’在同等生长环境下分蘖能力最强,‘肯塔基’分蘖能力最差,‘巴润’次之.

关键词: 草地早熟禾, 分蘖, 内源激素, 平均分蘖数