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草业学报 ›› 2019, Vol. 28 ›› Issue (2): 121-132.DOI: 10.11686/cyxb2018130

• 研究论文 • 上一篇    下一篇

遮阴和干旱对荩草克隆生长和有性繁殖及权衡关系的影响

徐晓霞1, 刘金平1,*, 游明鸿2, 张小晶1, 谢瑞娟1   

  1. 1.西华师范大学西南野生动植物资源保护省部共建教育部重点实验室,四川 南充 637009;
    2.四川省草原科学研究院,四川 成都 611731
  • 收稿日期:2018-03-09 出版日期:2019-02-20 发布日期:2019-02-20
  • 通讯作者: *E-mail: jpgg2000@163.com
  • 作者简介:徐晓霞(1994-),女,四川德阳人,在读硕士。E-mail: 826949490@qq.com
  • 基金资助:
    西华师范大学国培项目(17C046)和四川省植物资源共享平台(TJPT20160021)资助

Effects and trade-offs of shading and drought on clonal growth, and sexual reproduction in Arthraxon hispidus

XU Xiao-xia1, LIU Jin-ping1,*, YOU Ming-hong2, ZHANG Xiao-jing1, XIE Rui-juan1   

  1. 1.China West Normal University and Key Laboratory of Education on Southwest China Wildlife Resoureces Conservation, Nanchong 637002, China;
    2.Academy of Sichuan Grassland Science, Chengdu 611731, China
  • Received:2018-03-09 Online:2019-02-20 Published:2019-02-20
  • Contact: *E-mail: jpgg2000@163.com

摘要: 以可建植边坡草坪的野生荩草为材料,设置遮阴(5个水平)和干旱(4个水平)交互形成的20个组合处理,测定克隆生长性状和有性繁殖数量及生物量结构,分析不同遮阴和干旱组合处理下克隆效率指数(CEI)、繁殖分配(RA)、繁殖效率指数(REI)、繁殖指数(RI)、繁殖比率(RR)的差异,研究遮阴和干旱对荩草克隆生长和有性繁殖及权衡关系的影响,结果表明:1)遮阴和干旱对克隆子株数及克隆效率指数有显著影响,中、重度干旱和≥10%遮阴显著降低了子株数(P<0.05),干旱对CEI无影响、遮阴降低了CEI,交互作用极显著降低了基株的子株数和CEI(P<0.01)。2)遮阴和干旱对母株、子株和基株的花穗数和小花数,对繁殖器官生物量(ROB)、非繁殖器官生物量(NROB)和总生物量(TB)有显著影响(P<0.05),轻、中度干旱或10%~30%遮阴或轻度遮阴和轻度干旱组合可显著增加母株、子株、基株的花穗数和小花数,轻度干旱或10%遮阴或轻度干旱和轻度遮阴组合可显著增加TB和ROB,交互作用是影响基株花穗数和小花数、TB、ROB和NROB的主要因子,干旱对TB和NROB影响次之,遮阴对ROB影响较大。3)遮阴和干旱对RA、REI、RI和RR有显著影响(P<0.05),轻中度干旱或10%遮阴可提高基株的繁殖参数,重度干旱或≥30%遮阴度降低了有性繁殖(P<0.05),轻度遮阴和轻度干旱组合比单一处理更利于有性繁殖,轻度干旱可缓解中重度遮阴对有性繁殖的影响,繁殖参数主要受交互作用影响,遮阴次之,干旱较小。4)荩草可依据遮阴和干旱胁迫程度,进行克隆生长和有性繁殖权衡,遮阴≥30%可延长克隆生长10~34 d,中、重度干旱缩短克隆生长而促进有性繁殖,≥10%遮阴可缓解重度干旱对有性繁殖的影响(P<0.05)。5)20个遮阴和干旱组合处理下荩草均能同时维持两种繁殖方式,水分充足和全光照利于克隆生长,轻中度干旱和轻度遮阴单一或组合处理利于有性繁殖,遮阴和干旱交互影响增加了荩草的两种繁殖能力。

关键词: 荩草, 克隆生长, 有性繁殖, 草坪草, 繁殖效率

Abstract: Arthraxon hispidus, is a wild grass with potential for development as a turf plant for sloping ground. In this study, 20 treatments were set up by a factorial combination of five shade levels (0, 10%, 30%, 50%, 70%) and four drought levels (adequate moisture, mild drought, moderate drought and severe drought). The purpose was to study the combined effects of shade and drought on growth of A. hispidus, and identify trade-offs between clonal growth and sexual reproduction. Various data, including clonal growth traits, number of seed-heads, and biomass structure were gathered, and differences in cloning efficiency index (CEI), reproductive allocation (RA), reproductive efficiency index (REI), reproduction index (RI) and ratio of breeding (RR) under the 20 treatments were analyzed. It was found that: 1) Shade and drought stress had significant effects on clonal daughter ramet number and CEI. Moderate and severe drought and over 10% shading significantly reduced daughter ramet number. Drought had no effect on CEI and shade decreased CEI, and a shade x CEI interaction (P<0.01) was observed, expressed as a reduced daughter ramet and genet number, and reduced CEI. 2) Shading and drought had significant effects on flower spike numbers and floret numbers of mother ramets, daughter ramets and genets, reproductive organ biomass (ROB), non-reproductive organ biomass (NROB) and total biomass (TB) (P<0.05). Light and moderate drought or 10%-30% shade or the combination of mild shade and mild drought significantly increased flower spike number and floret number of mother ramets, and of daughter ramets and genets. Mild drought or 10% shading or the combination stress of mild drought and light shade all significantly increased TB and ROB. Moreover, a synergistic interaction between shade and drought strongly increased flower spike number and floret number of genets, and TB, ROB and NROB. The effect of drought on TB and NROB was followed, and shading had greater influence on ROB. 3) Shading and drought significantly (P<0.05) affected RA, REI, RI and RR: mild and moderate drought or 10% shading significantly increased the genet reproductive parameters, but severe drought or more than 30% shading significantly reduced reproductive parameters (P<0.05). Compared with either single stress, the combined stresses of light shading and mild drought promoted sexual reproduction. Mild drought alleviated reduction in sexual reproduction observed under moderate and severe shading. Reproductive parameters typically displayed a synergistic effect, with shading the larger effect, and the drought effect smaller. 4) A. hispidus displayed an altered balance between clonal growth and sexual reproduction, depending on the degree of shading and drought. Greater than 30% shade prolonged the period of clonal growth by 10-34 days. 5) Under all 20 treatment combinations of shading and drought, A. hispidus maintained both clonal and sexual reproduction concurrently. Adequate water and light promoted clonal growth. Light and moderate drought, and mild shade alone or in combination with drought were treatments that promoted sexual reproduction.

Key words: Arthraxon hispidus, clonal growth, sexual reproduction, turfgrass, reproductive efficiency