干旱对细叶结缕草和入侵杂草丝茅的竞争、生长及抗旱性的影响  

Effects of drought on competition, growth, and resistance of the lawn species Zoysia tenuifolia to the invasive weed Imperata koenigii

作　　者：曾晓琳[1] 李莹[1] 刘金平[1] 游明鸿[2] 黄曦叶 黄柳 ZENG Xiao-lin;LI Ying;LIU Jin-ping;YOU Ming-hong;HUANG Xi-ye;HUANG Liu(College of Life Sciences,China West Normal University,Nanchong 637009,China;Sichuan Academy of Grassland Sciences,Chengdu 611731,China)

机构地区：[1]西华师范大学生命科学学院,四川南充637009 [2]四川省草原科学研究院,四川成都611731

出　　处：《草业学报》2019年第11期46-59,共14页Acta Prataculturae Sinica

基　　金：西华师范大学国培项目(17C046);四川省植物资源共享平台(TJPT20160021)资助

摘　　要：针对亚热带地区伏旱频发条件下,丝茅入侵细叶结缕草草坪引起功能退化的问题,通过设置4个干旱梯度(水分充足、轻度、中度和重度干旱),采用取代试验设计了5个不同比例的丝茅入侵细叶结缕草草坪试验,进行60 d干旱处理后,测定丝茅和结缕草地下和地上相对产量、相对产量总和、攻击力、竞争平衡指数等竞争指标,分析两种植物的株高、分蘖数、叶片数、生物量和根冠比等生长指标,比较超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、可溶性糖(SS)、可溶性蛋白(SP)、脯氨酸(Pro)、丙二醛(MDA)等生理指标,研究干旱对两种植物之间的竞争、生长及抗性系统的影响。结果表明:1)干旱程度和丝茅入侵比例对两种植物的地上和地下竞争指标产生显著影响(P<0.05),轻度干旱且丝茅入侵比例≤30%时,结缕草地下攻击力指数和地下竞争平衡指数为正值,中度和重度干旱使结缕草种间竞争力丧失,当丝茅入侵比例≥20%时,拮抗作用使结缕草易被排挤出群落。2)干旱主要影响结缕草地下竞争力,丝茅入侵主要影响结缕草地上竞争力,干旱和丝茅入侵协同作用对结缕草地下攻击力和地下平衡指数影响大于地上部分,随干旱程度和丝茅入侵比例增加结缕草地上和地下竞争力降为负值。3)轻度干旱利于两种植物生长,中度和重度干旱降低了结缕草的株高、分蘖数、叶片数和单株生物量,对丝茅影响较少;>10%丝茅入侵比例限制了结缕草分蘖数和叶片数,>20%则降低了结缕草单株生物量和根冠比,干旱和丝茅入侵协同作用抑制了结缕草生长与再生能力。4)结缕草SOD、POD和CAT含量随干旱程度增加而显著增加(P<0.05),轻度干旱对丝茅SOD无影响而降低了CAT活性(P<0.05);>10%丝茅入侵比例增加了结缕草SOD活性,>20%增加了CAT活性,>30%增加了POD活性(P<0.05)。干旱对结缕草影响为CAT>SOD>POD,对丝茅为SOD>In subtropical areas, there is frequent functional degradation of Zoysia tenuifolia lawn by invasion of Imperata koenigii during summer drought. To explore the relationship between these two species under drought, we planted Z. tenuifolia and I. koenigii in five different proportions(9∶1, 8∶2, 7∶3, 6∶4, 5∶5), and after 40 days of growth, imposed four different drought treatments(adequate water, mild drought, moderate drought, and severe drought). After 60 days of the drought treatments, competitive indicators including relative yield, total relative yield, attacking power, and competitive equilibrium index were determined for both plant species. We also analyzed growth indexes including plant height, tiller number, leaf number, biomass, and the root∶shoot ratio, as well as physiological indexes including superoxide dismutase(SOD), peroxidase(POD), and catalase(CAT) activities, and the contents of soluble sugars(SS), soluble protein(SP), proline(Pro), and malondialdehyde(MDA). These analyses allowed us to compare the effect of drought on the competition, growth, and resistance systems of the two plant species. The results showed that: 1) The degree of drought and proportion of I. koenigii significantly affected the aboveground and underground competition index of both plant species(P<0.05). Under mild drought conditions and with a small proportion of I. koenigii(≤30%), the underground attacking power index and competition balance index of Z. tenuifolia were both positive. Moderate and severe drought caused the loss of the interspecific competitiveness of Z. tenuifolia. When the proportion of I. koenigii was ≥20%, its antagonistic effect was strong enough to exclude Z. tenuifolia from the community. 2) Drought mainly affected the underground competitiveness of Z. tenuifolia, yet the invasion of I. koenigii mainly affected the aboveground competitiveness of Z. tenuifolia. The synergistic effect of drought and invasion of I. koenigii had a greater impact on the attacking power and balance index of und

关 键 词：细叶结缕草 丝茅 攻击力 竞争力 干旱 

分 类 号：S51[农业科学—作物学]