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草业学报 ›› 2019, Vol. 28 ›› Issue (8): 106-118.DOI: 10.11686/cyxb2018490

• 研究论文 • 上一篇    下一篇

高温冲击对受丝茅入侵的细叶结缕草现实和潜在竞争力的影响

汪智宇, 李莹, 刘金平*, 伍德, 苟蓉   

  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
  • 收稿日期:2018-04-17 出版日期:2019-08-20 发布日期:2019-08-20
  • 通讯作者: *,E-mail: jpgg2000@163.com
  • 作者简介:汪智宇(1991-),男,四川广元人,在读硕士。E-mail: 842118522@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

Effect of high temperature shock on actual and potential competitiveness of Zoysia tenuifolia turf invaded by Imperata koenigii

WANG Zhi-yu, LI Ying, LIU Jin-ping*, WU De, GOU Rong   

  1. Key Laboratory of Southwest China Wildlife Resources Conservation, Ministry of Education, China West Normal University, Nanchong 637009, China
  • Received:2018-04-17 Online:2019-08-20 Published:2019-08-20
  • Contact: *,E-mail: jpgg2000@163.com

摘要: 针对亚热带地区丝茅入侵造成暖季型草坪退化的问题,模拟了40、42、44 ℃夏季高温条件,对取代试验设计形成的5个丝茅入侵的细叶结缕草草坪进行连续30 d (2 h·d-1)的高温冲击处理,测定丝茅和结缕草的地下和地上相对产量、相对产量总和、攻击力、竞争平衡指数等现实竞争参数,通过株高、分蘖数、叶面积、叶绿素和生理活性物质含量等指标,分析丝茅和结缕草的光合同化、再生能力和抗性生理等后续生长物质基础,研究高温冲击对不同入侵比例的丝茅和结缕草的现实和潜在竞争力影响。结果表明:1)高温冲击引起结缕草地上与地下相对产量的平衡性下降,丝茅表现为地上与地下均衡性降低,高温冲击增加了两种植物地上部分的拮抗作用,丝茅侵入量比高温冲击对结缕草相对产量的影响更大,≥30%侵入量与高温协同作用使结缕草地上与地下相对产量急剧下降。2)42 ℃时结缕草地上和地下攻击力指数及地上和地下竞争平衡指数最大,>42 ℃时结缕草攻击力和竞争平衡指数降低(P<0.05),但丝茅的攻击力和竞争平衡指数则增加。仅40和42 ℃条件下,当侵入量≤20%时,结缕草地上竞争力占优势,其他温度和侵入量条件下,丝茅地上和地下攻击力大于结缕草,从而有利于丝茅入侵和拓展。3)高温冲击增加了丝茅的株高和分蘖数,>42 ℃高温限制了结缕草的分蘖数,≥30%丝茅侵入量抑制结缕草分蘖而促进株高(P<0.05);高温冲击降低了结缕草叶片数和叶面积,增加了丝茅叶片数和叶面积,≥10%丝茅侵入量降低了结缕草叶面积,≥30%侵入量降低了结缕草叶片厚度和叶片数。4)高温冲击和丝茅入侵对结缕草叶绿素含量、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性和丙二醛(MDA)、脯氨酸(Pro)含量存在显著影响,结缕草生理反应比丝茅更易受到高温冲击的影响。5)高温冲击对结缕草形态、生理、相对产量及攻击力的影响大于丝茅,丝茅入侵对结缕草造成显著危害,高温和丝茅侵入量的协同作用,降低了结缕草的攻击力和竞争平衡指数等现实竞争力,限制了结缕草分蘖、光合及抗性物质等潜在竞争力。因此,控制丝茅侵入量≤20%是夏季结缕草草坪养护的基本要求。

关键词: 结缕草, 丝茅, 攻击力, 竞争力, 高温冲击

Abstract: This research investigated the problem of warm season Zoysia tenuifolia turf degradation caused by invading Imperata koenigii in the subtropical region of China. Pots 30 cm in diameter were prepared containing the two species in a replacement series; 9∶1, 8∶2, 7∶3, 6∶4, 5∶5 Z. tenuifoliaI. koenigii. The Z. tenuifolia was planted first and after it had formed 2-3 true leaves, the rhizomes of I. koenigii were inserted into Z. tenuifolia turf. After 40 days of normal culture, 3 replicate pots of each of the replacement series mixtures were placed into each of three controlled temperature chambers at 40, 42 and 44 ℃, for 2 hours each day over a period of 30 days, to provide a ‘high temperature shock’. Various parameters, including underground and aboveground relative yield, total relative yield, attack power and competition balance index, plant height, tiller number, leaf area, chlorophyll and physiological active substance, among others, were were determined on the 71st day. Subsequently, ‘resilience’ data such as photo-assimilate levels, regeneration capacity and resistance physiology were also collected. The aim was to study the effect of the high temperature shock on actual and potential competitiveness of Z. tenuifolia when challenged by I. koenigii invasion. It was found that: 1) High temperature shock was detrimental to Z. tenuifolia, and resulted in decline in the aboveground: below-ground relative yield, and a decline in competitiveness of Z. tenuifolia against I. koenigii. The high temperature shock increased the antagonism between the aerial parts of the two species. Invasion by I. koenigii had a greater effect on relative yield of Z. tenuifolia than high temperature shock. The synergistic effect of greater than 30% I. koenigii invasion and high temperature shock, sharply decreased the aboveground relative yield of Z. tenuifolia compared with underground yield. 2) Aboveground and underground attack force index and competition balance index for Z. tenuifolia were all at their maximum with a 42 ℃ heat shock. High temperature shock over 42 ℃ significantly reduced the attack power and competition balance index of Z. tenuifolia, and increased same indexes for I. koenigii. Only at 40 and 42 ℃, and with 20% I. koenigii invasion or less, was the competitiveness of Z. tenuifolia superior. At 44 ℃ or with 30% or greater presence of I. koenigii, the aboveground and underground attack power of I. koenigii were superior to Z. tenuifolia, as reflected by invasion and expansion of I. koenigii in the artificial turves. 3) High temperature shock increased height and tiller number of I. koenigii, and high temperature over 42 ℃ limited tiller number of Z. tenuifolia. The invasion of 30% I. koenigii or more, inhibited tillering but promoted height of Z. tenuifolia (P<0.05). High temperature shock also reduced the number of leaves and leaf area of Z. tenuifolia and increased these two traits in I. koenigii. Invasion by 10% or more I. koenigii reduced leaf area of Z. tenuifolia, and invasion by 30% or more I. koenigii reduced leaf thickness and leaf number of Z. tenuifolia. 4) High temperature shock and invasion of I. koenigii significantly affected the content of chlorophyll, superoxide dismutase, peroxidase, catalase, malondialdehyde and proline of Z. tenuifolia, indicating that the physiological response of Z. tenuifolia was more susceptible to high temperature shock than that of I. koenigii. 5) The influence of high temperature shock on morphology, physiology, relative yield and attack power of Z. tenuifolia was greater than the influence on the same indexes of I. koenigii. Invasion by I. koenigii caused significant damage to Z. tenuifolia turf. The synergistic effect of high temperature and I. koenigii invasion reduced the actual competitiveness of Z. tenuifolia and limited its potential competitiveness. Therefore, the basic requirement for conservating Z. tenuifolia turf is to control the proportion of invading I. koenigii to less than 20% in summer.

Key words: Zoysia tenuifolia, Imperata koenigii, attack power, competitiveness, high temperature shock