首页  |  本刊简介  |  编委会  |  投稿须知  |  订阅指南  |  联系我们  |  微信  |  出版道德声明  |  Ei收录本刊数据
13C脉冲标记法定量冬小麦光合碳分配及其向地下的输入
摘要点击 123  全文点击 39  投稿时间:2017-10-20  修订日期:2017-11-30
查看HTML全文 查看全文  查看/发表评论  下载PDF阅读器
中文关键词  冬小麦  土壤有机碳  13C脉冲标记  根际沉积  根际呼吸
英文关键词  winter wheat  soil organic carbon  13C pulse-labeling  rhizodeposition  rhizosphere respiration
作者单位E-mail
孙昭安 中国农业大学资源与环境学院, 农田土壤污染防控与修复北京市重点实验室, 北京 100193 sun.zhaoan@163.com 
陈清 中国农业大学资源与环境学院, 农田土壤污染防控与修复北京市重点实验室, 北京 100193  
韩笑 中国农业大学资源与环境学院, 农田土壤污染防控与修复北京市重点实验室, 北京 100193  
吴文良 中国农业大学资源与环境学院, 农田土壤污染防控与修复北京市重点实验室, 北京 100193  
孟凡乔 中国农业大学资源与环境学院, 农田土壤污染防控与修复北京市重点实验室, 北京 100193 mengfq@cau.edu.cn 
中文摘要
      研究冬小麦生长向地下部分的输入对于土壤固碳和作物生产具有重要意义.分别在分蘖期、拔节期、花期和灌浆期,用13CO2对冬小麦进行脉冲标记7 h,标记结束后28 d(示踪期)破坏性取样,测定冬小麦地上部、根、土壤和土壤呼吸中的13C含量等指标.研究结果表明,在各标记时期,冬小麦光合固定的13C大部分保留在地上部(51.6%~90.8%),且随小麦生长的进行而逐渐向地上部分配,向地下部分(根系、土壤和根际呼吸)的转移随生长进程的延续而降低.转移到地下部的13C中,有22.9%~65.3%被根际呼吸消耗,24.3%~59.3%在根部保存,10.4%~17.8%通过根际沉积转化为土壤有机碳.示踪期28 d内最后2 d呼吸产生的13C只占整个示踪期根际呼吸13C量的0.7%~2.7%,说明28 d的示踪期可以确保光合碳在各系统分配完全.在整个生育期内,冬小麦净吸收的光合碳分配到地上部、根部、土壤有机碳和根际呼吸的比例分别为78.5%、6.0%、3.1%和12.4%.结合当地生产方式估算,冬小麦在整个生育期内输入到地下的总碳量为1.72 t·hm-2,其中有0.99 t·hm-2被根际呼吸消耗,根部固持碳量为0.48 t·hm-2,0.25 t·hm-2以有机碳沉积的形式进入土壤.
英文摘要
      Evaluating the allocation of carbon (C) photosynthesized by winter wheat belowground is essential for C sequestration in soil and crop production. During the four growth stages of winter wheat, i. e., tillering, elongation, anthesis, and grain-filling, the method of 13CO2 pulse-labeling for the wheat was adopted. Destructive samplings were undertaken at 28 d after each labeling and the total C and 13C contents of shoots, roots, soil, and rhizosphere respiration were determined. Results showed that the majority of the fixed 13C was recovered in the aboveground (straw and grain), ranging from 51.6% to 90.8% in all growth stages. The allocation of 13C photosynthesized belowground (roots, soil, and rhizosphere respiration) decreased as the wheat growth advanced, while the 13C transferred to the aboveground increased. Of the total 13C input belowground, 22.9%-65.3% was respired by the rhizosphere, 24.3%-59.3% remained in the roots, and 10.4%-17.8% was incorporated into the soil organic carbon by rhizodeposition. Respired 13C within the last 2 d of the whole chase period (28 d) only accounted for 0.7%-2.7% of the total respired 13C, indicating that 28 days were long enough to ensure a complete distribution of photosynthesized C within all the wheat and soil pools. For the whole growth season of winter wheat, the photosynthesized C allocated aboveground, to roots, soil organic carbon, and rhizosphere respiration was 78.5%, 6.0%, 3.1%, and 12.4% of the net assimilated C, respectively. Based on local wheat production, the total C transferred belowground was quantified as 1.72 t·hm-2, with 0.99 t·hm-2 respired as rhizosphere respiration, 0.48 t·hm-2 retained in roots, and 0.25 t·hm-2 incorporated into soil organic carbon.

您是第12036363位访客
主办单位:中国科学院生态环境研究中心 单位地址:北京市海淀区双清路18号
电话:010-62941102,62849343 传真:010-62849343 邮编:100085 E-mail: hjkx@rcees.ac.cn
本系统由北京勤云科技发展有限公司设计  京ICP备05002858号