入侵植物香丝草水浸提液对蚕豆和玉米根尖染色体行为的影响  

Impact of Invasive Plant Conyza bonariensis on Vicia faba and Zea mays Root Tip Chromosomes Behaviour

作　　者：杨丽娟[1] 梁乾隆[1] 何兴金[1] 

机构地区：[1]四川大学生命科学学院,生物资源与生态环境教育部重点实验室,成都610065

出　　处：《西北植物学报》2013年第11期2172-2183,共12页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金资助项目(31070166;31100161;31270241);国家基础条件平台项目教学标本子平台资助(WEB:http://mnh.scu.edu.cn/)

摘　　要：以采自农田中自然生长的植物群落中的香丝草为供体,以典型的双子叶植物蚕豆和典型的单子叶植物玉米的幼苗为受体,运用根尖微核试验和染色体畸变试验,研究了香丝草的根、茎、叶和幼果4种器官水浸提液对受体的遗传毒性。结果表明:(1)在香丝草不同器官水浸提液作用下,蚕豆和玉米根尖细胞的有丝分裂各时期均受到明显影响,细胞中出现了微核、染色体桥、染色体断片、染色体环、染色体粘连及染色体滞后等多种染色体畸变。(2)香丝草各器官水浸提液对蚕豆幼苗根尖细胞分裂的抑制作用明显大于玉米。(3)香丝草各器官水浸提液对蚕豆和玉米幼苗根尖的染色体畸变诱导存在显著的浓度效应,即水浸提液浓度越高,受体的微核率和畸变率越高,相应的有丝分裂指数越低,水浸提液的诱导作用与浓度呈正相关关系,但不是简单的加和作用。(4)香丝草各器官水浸提液均具有较强的遗传毒性,但整体化感效应表现为叶>幼果>茎>根,即叶片产生的化感作用最强。因此,香丝草分泌的化感物质可能通过对受体植物生长点的细胞有丝分裂和细胞形态产生影响,造成受体植物染色体的多种畸变和不可逆的遗传损伤,从而成功入侵新的栖息地。In the study, Conyza bonariensis that collected from natural agricultural plant communities is taken as the donor,and typical dicotyledonous Vicia faba and typical monocotyledonous Zea mays seedlings as receptors. Micronucleus test and chromosome aberration test are used to investigate the genetic toxicity of aqueous extracts of different organs of C. bonariensis on the receptors. The results show that： （1）In the aqueous extracts of C. bonariensis,both root tip cells of V. faba and Z. mays in each phase of mitosis are significantly affected, which appear micronucleus, chromosome bridge, chromosome fragments, chromosome rings, lagging chromosomes, chromosome adhesions and other chromosomal aberrations; （2） The division inhibition effect of aqueous extracts from different organs of C. bonariensis on seedling root tip cells of V. faba is significantly greater than that of Z. maysl; （3）Chromosome aberrations of V. faba and Z.mays root tips induced by aqueous extracts of C. bonariensis present a significant concentration-dependent effect：the higher the concentration of the aqueous extracts, the higher the receptor micronucleus rate and distortion rate, and the lower the corresponding mitotic index,which show that the mutagenic effects of the aqueous extracts and concentration is positive correlation,but not a simple additive effect; （4）All the aqueous extracts from C. bonariensis have strong genetic toxicity,however,the whole performance of the atlelopathic effects from the organs is leaf〉fruitlet〉stem〉root. We suppose that the reason C. bonariensis successfully invade new habitats is that its secreted allelochemicals impact on mitosis and cell morphology of the growing point of receptors, resulting in a variety of chromosome aberrations and irreversible genetic damage.

关 键 词：香丝草 化感作用 蚕豆 玉米 根尖细胞 染色体行为 

分 类 号：Q945.7[生物学—植物学] Q343.24