基于根系与繁殖特征的风轮菜自我身份识别研究

Identity Recognition of Clinopodium chinense Based on Root and Reproductive Traits

【目的】克隆植物作为拥有遗传单一,亲缘性高等种群特点的一类植物,广泛分布于陆地生态系统并常占据优势地位,自然生境中的克隆分株常由于各种原因遭到破坏从而形成多个个体植株,但相邻克隆分株之间具有怎样的相互作用,它们之间是否存在自我识别以及这种识别是否会对有性繁殖产生影响尚不明确。因此探究克隆植物分株间自我识别响应特征,对理解克隆植物扩张过程及其环境适应机制具有重要理论意义。【方法】以亚热带地区草坪常见杂草风轮菜(Clinopodium chinense)为研究对象,采用根盒栽培试验,将每2棵分株栽为一组,设置匍匐茎连接组L(分株来自同一基株,匍匐茎保持连接)、自我组S(分株来自同一基株,匍匐茎剪断)和非我组NS(分株来自不同基株)3种处理,通过测定根表面积、根平均直径、根尖数、根系水平分布指数等根系参数和花序数量、花序轮数、最大轮间距等指标来研究不同处理组间根系行为与有性繁殖性状是否具有身份识别响应。【结果】连接组根系平均直径、根系角度差值比最低,根系活力最高,花序轮数最多,花序数量自移栽后20~38 d始终高于其他处理组。与自我组(S)相比较,非我组(NS)具有更高的根系平均直径,在移栽后的第32天,非我组(NS)花序数量显著低于自我组(S)。【结论】克隆植物风轮菜分株根系存在自我身份识别响应特征,这种识别对繁殖性状的影响具有时间差异。

[Objective]Clonal plants as a plant population with genetic oneness and close relatedness,are widely distributed in terrestrial ecosystems and often occupy a dominant position.And clonal plants in natural habitats are often damaged due to various reasons then those destroyed ramets form individual plants respectively.However,it is not clear what kind of interaction between these nearby clonal ramets and whether there is a self-recognition between ramets and whether such recognition has an effect on sexual reproduction.This paper aims to investigate the response of self-recognition between clonal ramets,and it is of great theoretical value to understand the expansion process and the adaptation mechanism of clonal plants.[Method]Clinopodium chinense,as one of the common weeds of lawn in subtropical area,were studied in the experiment designed with root box.Every two ramets were regarded as a group.The study set up three treatments,L group(ramets from the same genet with stolons remaining connected),S group(ramets from the same genet with stolons disconnected)and NS group(ramets from different genets which were from two patches),respectively.Aiming to explore whether there is any response on the root behavior and sexual reproductive traits of Clinopodium chinense to benefit its growth and reproduction by identity recognition,root parameters,such as root surface area,root average diameter,root tip numbers and root horizontal distribution index,as well as inflorescence numbers,inflorescence round numbers and the maximum distance between rounds,were measured in this study.[Result]The results showed that linked group had the smallest root average diameter,the strongest TTC reducibility and the lowest ADI and maintained an advantage on inflorescence numbers from 20d to 38d after transplanting.Comparing to the self group,the root average diameter of the non-self group was significantly higher.32 d after transplanting,the inflorescence number of the self group was extremely higher than that of non-self group.[Conclusion]The roots of Clinopodium chinense could identify the self/non-self plants and the effect of it on reproductive traits was reflected in the time difference.