不同播种方式下蒙古冰草和沙生冰草根系构型对干旱胁迫的响应  

Responses of Root Architecture of Agropyron mongolicum and Agropyron desertorum to Drought Stress under Different Sowing Patterns

作　　者：撒春宁 刘金龙 许冬梅[1,2] 李永康 刘梦鸽 SA Chunning;LIU Jinlong;XU Dongmei;LI Yongkang;LIU Mengge(College of Agriculture,Ningxia University,Yinchuan 750021,China;Ningxia Grassland and Animal Husbandry Engineering Technology Research Center,Yinchuan 750021,China)

机构地区：[1]宁夏大学农学院,宁夏银川750021 [2]宁夏草牧业工程技术研究中心,宁夏银川750021

出　　处：《中国草地学报》2023年第9期38-46,共9页Chinese Journal of Grassland

基　　金：国家自然科学基金项目(32060405);宁夏高等学校一流学科建设(草学学科)项目(NXYLXK2017A01)共同资助。

摘　　要：为探究不同播种方式下干旱胁迫对蒙古冰草和沙生冰草根系构型的影响,采用盆栽控制试验,基于单播和混播不同播种方式,分别设置田间持水量的80%(W1)、65%(W2)、50%(W3)、35%(W4)和20%(W5)5个水分梯度,研究了蒙古冰草和沙生冰草根系构型的变化。结果表明:单播蒙古冰草在W1和W4水分处理下具有较高的根长、根表面积,混播蒙古冰草的比根长和比表面积随干旱胁迫的加剧呈增加趋势,以W5处理的4582.84 cm/g和521.85 cm^(2)/g最高;播种方式主要影响蒙古冰草的根长、比根长和分形维数。沙生冰草的根长、根表面积、平均根系直径、根体积及单株根系生物量随干旱胁迫的加剧总体呈先增加后降低的趋势,单播方式下以W2处理较高;在同一水分梯度下,各指标均呈现出混播显著高于单播。在W1、W4和W5水分处理下,混播蒙古冰草的相对竞争强度修正指数(CRCI)均为正值,分别为0.05、0.02和0.35;而沙生冰草在各水分梯度下的CRCI均为负值,表现出混播对沙生冰草生长的促进效应。隶属函数分析结果表明,混播提高了蒙古冰草和沙生冰草的抗逆性能;沙生冰草比蒙古冰草具有更强的抗逆性,能更有效地通过根系构型的可塑性变化适应播种方式和水分条件的改变。This study aimed to investigate the effects of drought stress on the root architecture of Agro⁃pyron mongolicum and Agropyron desertorum under different sowing patterns.A pot control experiment was conducted employing different sowing patterns(single sowing and mixed sowing).In this study,the field water capacity was set at 80%(W1),65%(W2),50%(W3),35%(W4),and 20%(W5),respectively.The results showed that under the W1 and W4 treatments,the single sowing of A.mongolicum had higher root length,root surface area.Specific root length and specific root surface area of mixed sowing A.mongolicum increased with the aggravation of drought stress,reaching the highest values of 4582.84 cm/g and 521.85 cm^(2)/g in the W5 treatment.Sowing patterns mainly affected the root length,specific root length,and fractal dimension of A.mongolicum.Moreover,root length,root surface area,average root diameter,root volume,and root biomass of individual A.desertorum plants initially increased and subsequently decreased with the intensification of drought stress,with the W2 treatment yielding higher values under single sowing pattern.In the same water gradient,all indicators of mixed sowing were significantly higher than those of the single sowing pattern.The relative competitive intensity correction index(CRCI)of A.mongolicum was positive in the W1,W4,and W5 water treatments,with values of 0.05,0.02,and 0.35,respectively.However,the CRCI of A.desertorum was negative across all water treatments,indicating a promotive effect of mixed sowing on the growth of A.desertorum.The membership function analysis underscored that mixed sowing pattern improved the stress resistance of both A.mongolicum and A.desertorum.In comparison with A.mongolicum,A.desertorum exhibited greater stress resistance and a capacity to adapt more effectively to changes of sowing patterns and water conditions through plasticity adjustments in root architecture.

关 键 词：蒙古冰草 沙生冰草 干旱胁迫 播种方式 根系特征 

分 类 号：S543.9[农业科学—作物学]