松嫩平原退化草地羊草种子萌发对环境因子的响应  

Responses of seed germination of Leymus chinensis to environmental factors in degraded grassland on Songnen Plain in China

作　　者：马红媛[1,2] 吕丙盛[1,2] 杨昊谕[1,2] 闫超[1,3] 梁正伟[1,2] 

机构地区：[1]中国科学院东北地理与农业生态研究所,长春130012 [2]中国大安碱地生态试验站,吉林大安131317 [3]中国科学院合肥物质科学研究院,合肥230031

出　　处：《植物生态学报》2012年第8期812-818,共7页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(41001027);中国科学院知识创新工程重要方向项目(KZCX2-YW-359-2);中国科学院重点部署项目(KZZD-EW-TZ-07-08)资助;吉林大学工程仿生教育部重点实验室开放基金(K201007)

摘　　要：研究了温度(恒温和变温)、水分(含水量2.5%–40.0%)和干旱胁迫、土壤类型(盐碱土和非盐碱土)和盐碱胁迫(NaCl和Na2CO3)等环境因子对羊草(Leymus chinensis)种子萌发的影响。恒温下未经打破休眠处理的羊草种子发芽率不足2%,变温下羊草种子发芽率可达85.3%,表明温度是影响羊草种子萌发的关键因素之一。羊草种子萌发的适宜土壤含水量为2.5%–15.0%,随着含水量继续增加,发芽率呈下降趋势。松嫩平原盐碱化土壤对羊草种子萌发具有显著的抑制作用,羊草种子在重度盐碱土(pH10.24)中发芽率仅为6.0%,而在非盐碱土中发芽率可达61.3%。羊草种子在萌发阶段的耐盐碱能力差,随着NaCl和Na2CO3浓度增加,发芽率呈显著下降趋势,且Na2CO3的抑制作用更强。松嫩平原盐碱环境下羊草种子萌发受到抑制是该地区羊草草地退化的原因之一。Aims Our objective is to study the seed germination of Leymus chinensis in response to critical environmental factors, including temperature, water content and drought stress, type of soils and the saline-alkali stress, in order to explain the mechanisms of degradation ofL. chinensis grassland on Songnen Plain in China. Methods We investigated seed germination of L. chinensis under four temperature regimes （two constant 28 ℃ and 35 ℃ and three fluctuating 5/28 ℃, 5/35 ℃ and 16/28 ℃）, 2.5%-40.0% water content and 0-30% polyethylene glycol 6000 （PEG） solution simulating drought stresses, two types of soils （saline-alkali and non-saline-alkali） and two kinds of salts （NaCl with concentrations from 0 to 500 mmol·L^-1 and NazCO3 from 0 to 100 mmol.L 1）. Important findings Fluctuating temperature is a necessary condition for high seed germination ofL. chinensis. One of the reasons for grassland degradation in this area is the degraded soil environment where seeds of L. chinensis could not regenerate.

关 键 词：休眠 生态因子 萌发 羊草 盐碱 

分 类 号：S543.9[农业科学—作物学]