Evaluation of drought resistance for Texas bluegrass, Kentucky bluegrass, and their hybrids
Evaluation of drought resistance for Texas bluegrass, Kentucky bluegrass, and their hybrids
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DOI：
10.2135/cropsci2004.1746
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发表时间：
2004-09-01
期刊：
影响因子：
2.3
通讯作者：
Meyer, WA
中科院分区：
文献类型：
--
作者：
Abraham, EM;Huang, BR;Meyer, WA
肯塔基州早熟禾（Poa pratensis L.; KBG）具有良好的草坪质量和充足的灌溉，但中度至低度抗旱性。肯塔基州早熟禾与得克萨斯州早熟禾的种间杂交TBG）是一种抗旱草，原产于得克萨斯州，已经将抗旱基因从TBG转移到KBG。本研究的目的是（i）调查是否有改善的抗旱性相比，无论是TBG或KBG通过检查生理反应的干旱胁迫;（ii）确定主要的生理因素与恢复能力，这些植物从干旱胁迫。在温室中，通过42 d的停灌使植物暴露于干旱胁迫。该实验由29个第四代回交杂种、1个第三代杂种（BDF）、2个KBG亲本（“C-74”、“Midnight”）和1个TBG亲本组成。根据相对含水量（RWC）、电解质渗漏率（EL）和光化学效率（Fv/Fm）对干旱胁迫的响应，将这些基因型分为高、中、低3个抗旱性类群。RWC和Fv/Fm随干旱胁迫的进行而下降，但高抗组维持在较高水平，EL随干旱胁迫的进行而升高，但高抗组较低。得克萨斯州早熟禾，午夜KBG，和两个杂交种的抗旱性排名最高。其它杂交种抗旱性差异较大，BDF × Midnight的杂交种比BDF × C-74的杂交种更多地进入高抗旱组。在所有的生理参数研究，EL是最敏感的指标，干旱胁迫，表现为最迅速的增加响应的压力。高Fv/Fm值和干旱胁迫期间绿色叶片的保持有助于复水后从干旱胁迫中快速恢复。
Kentucky bluegrass (Poa pratensis L.; KBG) has good turf quality with adequate irrigation, but moderate to low drought resistance. Interspecific hybridization of Kentucky bluegrass with Texas bluegrass (Poa arachnifera Torr.; TBG), a drought resistant grass native to Texas, has been made to transfer genes of drought resistance from TBG to KBG. The objectives of this study were (i) to investigate whether the hybrids have improved drought resistance compared with either TBG or KBG by examining physiological responses to drought stress; and (ii) to determine major physiological factors associated with recuperative ability of those plants from drought stress. Plants were exposed to drought stress by withholding irrigation for 42 d in a greenhouse. The experiment consisted of 29 fourth-generation backcrossed hybrids, one third-generation hybrid (BDF), two KBG parents ('C-74', 'Midnight'), and one TBG parent. The genotypes classified into three cluster groups of drought resistance (high, moderate, and low) based on the responses of relative water content (RWC), electrolyte leakage (EL), and photochemical efficiency (Fv/Fm) to drought stress. The RWC and Fv/Fm declined with drought stress, but were maintained at higher levels in the high resistance group than the other group, while EL increased during drought and was lower in the high resistance group. Texas bluegrass, Midnight KBG, and two hybrids were ranked highest in drought resistance. Other hybrids varied in drought resistance, with more hybrids of BDF X Midnight ranked in the high drought resistance group than the hybrids of BDF X C-74. Among all physiological parameters examined, EL was the most sensitive indicator to drought stress, as demonstrated by its most rapid increase in response to the stress. High Fv/Fm and retaining of green leaves during drought stress contributed to fast recovery from drought stress following rewatering.