摘要
目的:研究百蕊草半寄生机制。方法:采用石蜡切片法和电镜研究百蕊草根、茎、叶、吸器的显微结构和叶片超微结构。用紫外-可见分光光度法测定色素含量;用LI-6400便携式光合仪测定光合等生理参数日变化。结果:百蕊草叶肉细胞含有较多叶绿体,叶绿素含量丰富,叶绿体中具有完整的基粒类囊体系统,片层系统发达;百蕊草维管组织发达,根、茎木质部导管孔径较大,输导能力强;百蕊草侧根有许多圆球形吸器,吸器内维管组织发达,吸器探针穿透寄主根的表皮和皮层,直达髓部,在髓部吸器导管与寄主导管融合。百蕊草叶片光合能力强大,最大净光合速率可达7.06μmol.m-2.s-1,水分利用率为0.735 mmol.mol-1,蒸腾作用白天变化剧烈,夜晚相对平稳,白天为7.20 mmol.m-2.s-1显著高于夜间,夜间为0.85mmol.m-2.s-1。结论:百蕊草通过吸器从寄主体内夺取水分和养分;百蕊草可通过光合作用实现全部或大部分碳的自给。
Objective: To study the hemiparasitic mechanism of Thesium chinense.Method: The anatomical structure of T.chinense was studied by using paraffin slice and electron microscope slice.Chlorophyll content was measured by UV spectrometry.Foliar photosynthesis(Pn) and gas exchange were measured by using a LI-6400 photosynthesis system.Result: Chloroplast possesses intact granal thylakoid system,lamella was strong.Vascular tissue of T.chinense was strong.Vessel aperture and its transport power were strong both in root and stem.There were many global haustoriums on lateral roots.Vascular tissues were strong inside haustorium,haustorial stylet penetrated epidermis and cortex of host root,and reached pith place,haustorial vessel was integrated with host root vessel.The maximum of Pn of T.chinense reached 7.06 μmol·m-2·s-1,its water use efficiency was lower,about 0.735 mmol·mol-1,its transpiration varied notable in daytime and was relatively invariant at nighttime,and the value of daytime was greatly exceed that of nighttime.Conclusion: T.chinense despoils water and nutrition from its host by haustorium.T.chinense can mostly be independent as for C supply by photosynthesis.
出处
《中国中药杂志》
CAS
CSCD
北大核心
2012年第1期17-22,共6页
China Journal of Chinese Materia Medica
基金
国家自然科学基金项目(81173482)
国家科技基础条件平台项目(2005DKA21000)
关键词
百蕊草
半寄生机制
结构植物学
光合作用
Thesium chinense
hemiparasitic mechanism
morphology
photosynthesis
