母体放牧经历对羊草克隆后代干旱敏感性的影响  

Maternal grazing exposure altered the responses of Leymus chinensis cloned offspring to drought environment

作　　者：郭丰辉 丁勇[1] 马文静 李贤松 李西良[1] 侯向阳[1,2] GUO Feng-hui;DING Yong;MA Wen-jing;LI Xian-song;LI Xi-liang;HOU Xiang-yang(Institute of Grassland Research,Chinese Academy of Agricultural Sciences,Hohhot 010010,China;Pratacultural College,Shanxi Agricultural University,Jinzhong 030801,China;Inner Mongolia University for Nationalities,Tongliao 028000,China)

机构地区：[1]中国农业科学院草原研究所,内蒙古呼和浩特010010 [2]山西农业大学草业学院,山西晋中030801 [3]内蒙古民族大学,内蒙古通辽028000

出　　处：《草业学报》2021年第8期119-126,共8页Acta Prataculturae Sinica

基　　金：国家自然科学基金项目(31702161);内蒙古科技计划项目(201802081);中央级公益性科研院所基本科研业务费项目(1610332020001;1610332018012)资助。

摘　　要：母体放牧环境可以对后代子株产生遗留效应,同时,放牧可通过改变生态系统蒸散发格局及强度加剧干旱。然而,放牧遗留效应是否影响了植物对干旱的响应,尚知之甚少。从长期围封和放牧样地采集羊草克隆后代进行室内培养,研究了放牧遗留效应对羊草干旱适应性的影响。结果表明:1)相对于围封羊草克隆后代(NG),放牧羊草克隆后代(GZ)单株株高、单株生物量的干旱抵抗力更强,材料来源与干旱处理交互作用显著;相反,GZ子株数对干旱的响应比NG更敏感;2)NG与GZ地上生物量、总生物量对干旱具有相同的响应趋势和强度;3)NG总根茎长、总根茎节间数对干旱的响应更敏感,对照处理下NG总根茎长度、总根茎节间数显著大于GZ,而干旱处理下无显著差异;4)NG在干旱下减小根茎和地上分配,提高根系分配;而GZ在干旱下减小根茎分配、提高地上分配,根系分配无显著变化。结果表明,放牧遗留效应改变了羊草对干旱的响应模式,为认识放牧生态系统过程提供了新的角度。Grazing disturbance on maternal plants can induce legacy effects on the progeny plants. Meanwhile,grazing disturbance also can exacerbate ecosystem drought by changing the evapotranspiration pattern and intensity.However,little is known about whether the grazing-induced legacy effects regulate the response of progeny plants to drought. In this study,we conducted a greenhouse experiment with Leymus chinensis offsprings collected from longterm no grazing plots(which have been fenced for about 40 years)and seriously grazed plots to explore whether grazing could enhance the adaptation of the plant to drought. Results showed that:1) Relative to NG(cloned offspring collected from no grazing plots),individual height and biomass of GZ(cloned offspring collected from grazed areas)are more resistant to drought,and the interaction between material source and drought treatment is significant. In contrast,the response of GZ to drought in terms of ramet number is more sensitive than that of NG.2) NG and GZ exhibit similar responses to drought in terms of aboveground and total biomass. 3) NG is more sensitive to drought than GZ in terms of total rhizome length and internode number. Under control treatment,the total rhizome length and internode number of NG are significantly greater than GZ,while there are no significant differences under drought treatment. 4) Rhizome and aboveground biomass allocation of NG under drought treatment are higher than that under control treatment,while the root biomass allocation increases under drought treatment. However,for GZ,rhizome biomass allocation decreases and aboveground biomass allocation increases under drought treatment,while there is no significant change in terms of root biomass allocation. This study showed that the grazing-induced legacy effects altered the response pattern of L. chinensis to drought treatment. This information provides a new perspective for understanding grazing ecosystem processes.

关 键 词：放牧 遗留效应 干旱 羊草 生物量分配 

分 类 号：S543.9[农业科学—作物学]