植物获取碳新通道的初步研究

A Preliminary Study on New Channels for Plants to Obtain Carbon

为了探索验证植物通过根系直接吸收碳源途径存在的真实性,把甘蔗、香蕉组培苗放入密闭、全日光照、无CO_(2)和无微生物的环境中,将其培育在含葡萄糖、蔗糖、乳糖的培养基上,观察其生长情况并测定其生物量。结果表明,只要培养基含有一定浓度的葡萄糖、蔗糖或乳糖有机碳,在缺乏CO_(2)的环境中,甘蔗、香蕉苗都能生长良好。而在无有机碳源且缺CO_(2)的环境中,试材生长衰弱且时间长了会干枯死亡。因此甘蔗和香蕉能从根系吸收葡萄糖、蔗糖及乳糖,供地上部生长。此外本研究还在采用人工气候箱保证正常光合作用的条件下,通过沙培测试水稻秧苗在不同碳源补充情况下的生长状态,以此进一步验证水稻根系对土壤中碳源的吸收。结果显示,水稻苗在MS补充以上3种碳源条件下生长良好,补充无碳源MS的情况下初期生长良好,后逐渐生长迟缓直至干枯死亡。证实水稻苗能通过根系直接吸收碳源,同时发现,MS过量施用且缺乏碳源能导致土壤pH降低。研究结果证实,植物除了利用光合作用获取碳外,还可以通过根部吸收碳,获取生长所需要的碳源,合成生长所需物质,正常生长发育。

In order to explore the authenticity of plants to obtain carbon from soil by roots,sugarcane and banana were cultured in the medium containing glucose,sucrose and lactose in a closed,full-day light,CO_(2)-free and microbe free environment,and the growth and biomass of the test plants were observed.The results showed that sugarcane and banana seedlings could grow well in the absence of CO_(2) as long as the medium contained a certain concentration of organic carbon sources(glucose,sucrose and lactose).However,in the environment without organic carbon source and CO_(2),the test plants grow weak and dried up and died after a long time.sugarcane and banana could obtain glucose,sucrose and lactose by roots to support the growth of overground part.In addition,under the condition of normal photosynthesis,the growth state of rice seedlings under different carbon source supplement was tested by sand culture,so as to further verify the absorption of carbon source in soil by rice roots.The results showed that rice seedlings grew well when MS was supplemented with three carbon sources,grew well at the initial stage when MS without carbon source was supplemented,and then grew slowly until dry and died.It was confirmed that rice seedlings could directly absorb carbon source by root system.At the same time,it was found that the decreasing of soil pH was caused by the excessive application of MS and the lack of soil carbon source.The results of this study confirmed that plants can not only obtain carbon by photosynthesis,but also obtain carbon source for growth by absorbing carbon from roots,and synthesized the substance needed for growth.