克隆整合是否有助于空心莲子草抵抗菟丝子的短期寄生?

Does clonal integration help alligator weed resist short-term parasitism by dodder?

关于克隆植物通过克隆整合抵御逆境能力影响的研究已有很多,但克隆整合是否能抵御植物寄生的研究还比较缺乏。本文利用匍匐茎克隆植物空心莲子草和1年生寄生植物菟丝子作为研究系统,检验假说"克隆整合有助于克隆植物抵抗寄生植物的寄生胁迫"。在实验中,相连分株分别经历了以下处理:M+-D-(分株对中母株被寄生,子株不被寄生),M--D+(母株不被寄生,子株被寄生),M+-D+(母株、子株均被寄生),M--D-(母株、子株均不被寄生)。研究发现,菟丝子寄生显著影响了空心莲子草的叶绿素相对含量、最大光量子产量等生理指标,以及叶片数、匍匐茎长度、分株数等生长指标,但不同处理间的生物量没有显著差异。本实验的结果没有支持实验假说。这样的结果可能是由于本实验时间较短所引起的,表明克隆整合适应性的表达不是无条件的。进一步实验应该既能够检验短期效应也能够检验长期效应。

Many studies have focused on how clonal plants cope with stressful environments through clonal integration. We tested the hypothesis that clonal integration can help clonal plants resist parasitism by plants in an experiment in which stoloniferous alligator weed （Alternanthera philoxeroides） experienced partial infection by parasitic dodder （ Cuscuta chiuensis）. Interconnecting ramets of alligator weed were assigned to the following treatments ： M^＋-D-（ only mother ra- mets infected）, M^--D＋ （ only daughter ramets infected）,M^＋-D＋ （ both mother and daughter ra- mets infected）, M^--D- （ no infection）. Relative chlorophyll content, Fv/F,n, number of leaves, stolon length and number of ramets significantly responded to the infection while biomass did not. Our results did not support the hypothesis, which might be due to our relatively short experimental term, suggesting that adaptive expression of clonal integration is not unconditional. Further studies should be able to take both short- and long-term effect into account.