基于^(32)P示踪的不同供磷环境杉木幼苗磷的分配规律分析  

Phosphorus distribution inside Chinese fir seedlings under different P supplies based on ^(32)P tracer

作　　者：陈思同 邹显花[1,2] 蔡一冰 韦丹 李涛 吴鹏飞[1,2] 马祥庆[1,2] CHEN Si-Tong;ZOU Xian-Hua;CAI Yi-Bing;WEI Dan;LI Tao;WU Peng-Fei;MA Xiang-Qing(Forestry College of Fujian Agriculture and Forestry University, Fuzhou 350002, China;State Forestry Administration Chinese Fir Engineering ResearchCenter, Fuzhou 350002, China)

机构地区：[1]福建农林大学林学院,福州350002 [2]国家林业局杉木工程技术研究中心,福州350002

出　　处：《植物生态学报》2018年第11期1103-1112,共10页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(U1405211);福建省科技重大专项(2018NZ0001-1)~~

摘　　要：通过分析杉木(Cunninghamia lanceolata)幼苗磷(P)分配规律,可以阐明两个磷高效利用杉木在不同供磷水平下吸收外源磷的分配及动态变化,为进一步进行磷高效利用基因型的选育提供参考。该研究以2个磷高效利用杉木家系(被动忍受型M1与主动活化型M4)幼苗为试验材料,利用^(32)P同位素示踪技术,研究在不同供磷水平下2个杉木家系幼苗磷分配规律。结果表明,M1和M4吸收的外源磷的含量分布特征均为根>叶>茎,自显影中相同处理时期的各器官在水平投影面上^(32)P含量均为根>茎>叶。低磷处理下M1和M4根、茎、叶吸收的外源磷的含量均明显低于高磷处理,自显影中相同处理时间根、茎、叶低磷水平下成像的黑化程度也低于高磷水平,且低磷处理下吸收的外源磷的含量增加缓慢,说明低磷胁迫严重影响杉木苗磷的吸收与积累。M1和M4的根系磷分配率在低磷胁迫下呈现出明显的先减少后增加趋势,高磷水平下根系磷分配率表现为先增加后趋于平稳。这说明M1和M4可以通过体内磷的重新分配来适应外界低磷胁迫,即杉木苗在低磷胁迫初期将根系中的磷转移至地上部分,随着胁迫时间的延长,地上部分的磷向根系中转移。但两个家系在低磷条件下对吸收的外源磷的分配格局差异明显:从开始至结束M1吸收的外源磷的分配率表现为根系>地上部分,而M4先表现为根系>地上部分,后表现为地上部分>根系,说明M1在低磷胁迫后加强体内磷循环的程度相比于M4更高,即磷从地上部分向根系转移的趋势更强烈。Aim The objective of this study was to determine the amount and distribution of exogenous phosphorus(P)in different organs,as well as their changes in Chinese fir(Cunninghamia lanceolata)under different P supply levels.The results could be used as scientific base for selecting P-efficient genotypes.Methods Seedlings of two Chinese fir genotypes(M1 and M4),both with high P use efficiency,were treated with different P supply levels and quantified by using 32P isotope tracer for P distributions in different organs.The seedlings used in this study were selected by our team through previous research as the experimental materials.Important findings We found that the distribution of exogenous P in M1 and M4 was the highest in the roots and the lowest in the stems,and at an intermedia level in the needles.The 32P content of each organ under the same treatment was ranked as root>stem>needle on the horizontal projection plane.The exogenous P content by the roots,stems and needles of M1 and M4 under low-P treatment appeared lower than that under the high-P treatment.The blackening degree of low-P image of roots,stems and needles under the same treatment was also lower than that under high-P treatment.The content of exogenous P in these organs under the low-P treatment increased slowly,indicating that the low-P stress significantly affected the absorption and accumulation of P in the seedlings.P allocation rates in the roots of M1 and M4 showed an initial decreasing and increasing later under low-P stress,while under the high-P treatment,the root P level increased first and stabilizing later.These findings indicate that M1 and M4 could adapt to external low-P stress through redistribution of P within the plants by transferring P from roots to above-ground parts at the early stage under low P stress.With the extension of stressing time,P from above-ground parts was shifted to roots.However,the distribution of exogenous P in M1 and M4 was significantly different under the low P treatment.The distribution of exogenous P from th

关 键 词：杉木 磷分配 ^32P同位素 低磷胁迫 磷利用效率 放射自显影 

分 类 号：S791.27[农业科学—林木遗传育种]