王新雨 王志勇 王文强 孙秋南 杨虎彪 廖丽 付玲玲

摘  要：以40份竹节草（Chrysopogon aciculatus）种质为材料，采用0（CK）、15%（T1）和20%（T2）3种浓度的PEG-6000溶液模拟干旱胁迫，对其进行抗旱性初步评价。结果表明，随着PEG浓度增加，干旱胁迫下不同竹节草种质枯黄率和萎蔫系数呈增加趋势，不同处理间差异显著;相对于T1处理，T2处理下枯黄率和萎蔫系数增幅更大，变化更明显;T1处理可促进根系生长，而T2处理有抑制作用，种质间呈现显著性差异。相关性分析表明，枯黄率、萎蔫系数、相对总根长、相对根体积、相对根表面积之间均呈现极显著相关，相对根直径与萎蔫系数、相对根长之间显著相关，与其他形态指标之间无显著相关性，运用隶属函数对竹节草抗旱性进行综合分析，分为抗旱种质（CA04、CA26、CA23、CA58）和敏旱种质（CA03、CA59、CA78、CA40）。本研究结果可为今后开展竹节草抗性育种提供参考。

关键词：竹节草;种质资源;抗旱性;PEG干旱胁迫;评价

Abstract： In this study， 40 Chrysopogon aciculatus germplasms were used as the materials to simulate drought stress in PEG-6000 solutions at three concentrations of 0 （CK）， 15% （T1） and 20% （T2）， and to evaluate the drought resistance. With the increase of PEG concentration， the withering rate and wilting coefficient under drought stress showed an increasing trend and there had significant difference between different treatments. Compared with T1 treatment， the withering rate and wilting coefficient increased significantly and changed more obviously under T2 treatment. T1 treatment promoted root growth， while T2 treatment inhibited， and there were significant differences among germplasms. Correlation analysis showed that there was a significant correlation among withering rate， wilting coefficient， relative total root length， and relative root volume and relative root surface area were significantly positively correlated， while the relative root diameter had a significant correlation with wilting coefficient and relative root length， and there was basically no correlation between relative root diameter and other morphological treat. The drought resistance of C. aciculatus was comprehensively analyzed by membership function， which was divided into drought-resistant germplasm （CA04， CA26， CA23， CA58）， and drought-sensitive germplasm （CA03， CA59， CA78， CA40）. The study would provide a reference for developing resistance breeding of C. aciculatus in future.

Keywords： Chrysopogon aciculatus; germplasm; drought resistance; PEG drought stress; evaluation

干旱是最具破壞性的环境压力之一，是影响植物生长、发育和导致产量降低的主要环境因素之一[1]。全球干旱、半干旱地区约占陆地面积的40%[2]，且有逐年增加的趋势。为了适应干旱胁迫，植物进化出一系列的耐旱机制，使其能够在干旱胁迫下生存。在干旱条件下，植物会通过改变其外部形态，如株高、叶片大小、叶色、根系生长、调节光合生理和代谢以适应干旱胁迫[3-5]。抗旱性差异和相关防御机制不仅在植物物种之间不同，而且在单个植物物种内部也不同[6-8]。随着经济发展和国民生态意识的加强，草坪种植面积不断增加，草坪灌溉缺水问题日益严重，已成为草坪业发展的最大限制因素之一[9]。……