广州地区5种野生豆科植物及其根瘤的比较鉴别研究

Comparative Identification of Five Wild Leguminous Plants and Their Root Nodules in Guangzhou Area

【目的】观察广州地区5种野生豆科植物(三点金、蔓花生、田菁、美洲合萌和链荚豆)的外观形态特征及其根瘤在不同季节的生长状况、形态及显微结构特征。【方法】每月分别采集新鲜的上述5种植物为样品,观察植株的外观形态特征及根瘤的生长部位、形态、颜色和大小;采用显微观察法对5种植物根瘤的显微结构进行研究。【结果】原植物形态:5种植物花冠的颜色差异显著。三点金呈紫红色;蔓花生呈金黄色;田菁呈黄色;美洲合萌呈灰黄色,具数条深色线;链荚豆呈紫蓝色。根瘤的生长状态:5种植物根瘤的数量和特征呈季节性变化。12月至次年2月,链荚豆无根瘤;1月,三点金无根瘤;12月至次年3月,田菁无根瘤。根瘤的显微结构:5种植物根瘤结构都由4部分组成,由外向内依次为:周皮、皮层、维管系统和侵染组织。【结论】本研究结果可为5种野生豆科植物的分类、根瘤的采收季节提供依据,为根瘤菌的分离、鉴定和开发利用等研究奠定基础。

Objective To observe the appearance features of 5 species of wild leguminous plants Desmodium triflorum（Linn.）DC., Arachis duranensis Krap. et Greg, Sesbania cannabina（Retz.）Poir., Aeschynomene americana L. and Alysicarpus vaginalis（L.）DC. in Guangzhou,and to investigate the growth status,morphologyand microstructure features of their root nodules at different seasons. Methods Fresh plants of the 5 wildleguminous plants were monthly harvested as samples. We observed the appearance features of the plants as well asthe growth conditions,morphology,color and size of their root nodules. And the microstructure features of the rootnodules were detected by microscopy. Results The morphologic features of original plant were as follows：the colorof corolla of 5 plants was significantly different, of which the corolla of Desmodium triflorum（Linn.）DC. waspurple and red,the corolla of the Arachis duranensis Krap. et Greg was golden yellow,the corolla of the Sesbania cannabina（Retz.）Poir. was yellow,the corolla of the Aeschynomene americana L. was grayish yellow with severaldark lines on the corolla,and the corolla of the Alysicarpus vaginalis（L.）DC. was purplish blue. The number andcharacteristics of root nodules of 5 species of plants showed seasonal variations：from December to February of thefollowing year, Alysicarpus vaginalis（L.）DC. had no root nodule; in January, no root nodule was found in Desmodium triflorum（Linn.）DC.;Sesbania cannabina（Retz.）Poir. had no root nodule from December to Marchof the following year. The microstructure features of the root nodules showed as follows：the root nodules of all 5 species of plants were composed of 4 parts, and they were periderm, cortex, vascular system, and infected tissues in the outside-to-inside sequence. Conclusion The results will provide reference for classification of the 5 wild leguminous plants and for the optimization of harvest season for their root nodules,which will also lay the foundation for the isolation,identification,development and utilization of rhizobium from these plants.