Allelopathic effects of exotic mangrove species Laguncularia racemosa on leaf ultrastructure of Bruguiera gymnorhiza seedlings
- 环境生态－已发表论文 
探讨外来速生红树植物拉关木(Laguncularia; racemosa)扩张过程中潜在的化感作用,为其入侵风险评估提供参考。通过室内栽培试验测定拉关木根、枝、叶、果的水浸液不同质量浓度(0.1; g·mL~(-1)、0.5 g·mL~(-1))对我国乡土红树植物木榄(Bruguiera; gymnorhiza)幼苗叶片超微结构的影响。结果表明,在拉关木根、叶、果的水浸液低浓度(0.1; g·mL~(-1))处理下,木榄幼苗的叶肉细胞内的叶绿体紧密排列在细胞壁周围,线粒体结构保持完好;而在拉关木枝的水浸液低浓度(0.1; g·mL~(-1))处理下,木榄幼苗叶肉细胞内的液泡轻微皱缩,出现轻微的质壁分离现象。拉关木枝、果水浸液高浓度(0.5; g·mL~(-1))处理下,木榄幼苗叶片叶肉细胞的叶绿体内的淀粉粒变多,变大,线粒体内部结构出现降解;拉关木根的水浸液高浓度(0.5; g·mL~(-1))处理下,部分叶绿体结构受到破坏,但线粒体结构基本保持较好;而在拉关木叶的水浸液高浓度(0.5; g·mL~(-1))处理下,木榄叶片叶肉细胞的超微结构基本保持完好,表明拉关木叶水浸液对木榄幼苗的化感抑制作用弱。本研究中拉关木各器官高浓度(0; .5 g·mL~(-1))水浸液对木榄幼苗叶片超微结构的化感作用强弱顺序为:枝>果>根>叶。In order to provide a reference for the invasion risk assessment of; fast-growing alien mangrove species of Laguncularia racemosa,the aqueous; extracts of different concentrations(0.1 mg·L~(-1),0.5 mg·L~(-1)) of; roots,stems,leaves and fruits of L. racemosa were used to determine the; allelopathic effects on the leaf ultrastructure of seedlings of; Bruguiera gymnorhiza native species in China by indoor cultivation; experiment. The results of this study show that when subjected to the; concentration of 0.1 mg·L~(-1) aqueous extracts from L. racemosa roots; and fruits,the number of chloroplasts in the mesophyll cells of B.; gymnorhiza seedlings increased and mitochondria were delimited by a; double mitochondria membrane,as well as showed clear cristae inside an; electrondense stroma;when subjected to the concentration of 0.1; mg·L~(-1) aqueous extracts of L. racemosa stems,the vacuoles of the; mesophyll cells in the mesophyll cells of B. gymnorhiza were slightly; shrunk and a slight wall separation was observed. Whereas subjected to; the concentration of 0.5 mg·L~(-1) aqueous extracts from L. racemosa; stems and fruits,the size and number of starch grains of chloroplast; were increased,and the mitochondria were deformed and seriously; degraded. When subjected to the concentration of 0.5 mg·L~(-1) aqueous; extracts from L. racemosa roots,some parts of chloroplast were; damaged,but the mitochondria structure basically remained intact;whereas; subjected to the concentration of 0.5 mg·L~(-1) aqueous extracts from L.; racemosa leaves,both the chloroplast and mitochondria in mesophyll cells; of B. gymnorhiza seedlings basically remained intact,which showed that; the inhibitory effect of the aqueous extract of L. racemosa leaves was; weak. When subjected to the concentration of 0.5 mg·L~(-1) aqueous; extracts from different organs of L. racemosa,the allelopathy intensity; order on the ultrastructure of leaves of B. gymnorrhiza seedlings was:; stem>fruit>root>leaves.