华北冬小麦品种演变过程中CO 2补偿点变化分析

摘要

Compensation point to CO2 is one of the key parameters for crop growth model.Systematic measure-ments of parameters for physiological-ecology of different varieties of winter wheat before 1949 and from 1949 to 2005 in North China were conducted using a Licor-6400.Based on these measurements,rectangular hyperbolic photosynthetic models of different winter wheat varieties in North China involving the function of CO2 were fitted in order to determine compensation point to CO2 in different varieties in different time.The results indicate that the compensation point to CO2 decreases with increase of photosynthetic photon flux density(PPFD)in North China. Under 800 μmol·m-2·s-1 PPFD conditions,the compensation point to CO2 of the wild variety is the highest,reac-hing 123. 40μmol·mol-1 .During 1949-2005,the compensation point to CO2 varies obviously with varieties,with the highest value of 107. 07 μmol·m-2·s-1 for the Taishan No.1 variety and the lowest value of 57. 25 μmol·mol-1 for the Hongtutou variety.Difference of maximum and minimum values between different varieties of winter wheat reaches 49. 82 μmol·mol-1 ,and it suggests that compensation point to CO2 changes significantly with evolution of winter wheat varieties in North China.The study establishes rectangular hyperbolic photosynthetic models of seven typical winter wheat varieties in North China involving the function of CO2 ,and identifies the compensation point to CO2 ,which provide the basic data set to develop crop models for evaluation of impact of climate change on ag-riculture in North China.%CO2补偿点是作物生长模型中最基本的关键模型参数之一，本文利用Licor-6400便携式光合作用测定仪，对1949年前和1949—2005年中国华北地区不同年代冬小麦主要品种的生理生态参数进行大量的系统测定，在此基础上，对华北地区不同冬小麦品种的光合作用模型进行拟合，以确定不同年代不同品种冬小麦CO2的补偿点。结果表明：中国华北地区冬小麦CO2补偿点随光强升高而降低，在800μmol·m－2·s－1光量子通量密度条件下，野生麦种 CO2补偿点最高，达123.40μmol·mol－1。1949—2005年华北地区不同冬小麦品种中泰山1号CO2补偿点最高，达107.07μmol·mol－1；红秃头CO2补偿点最低，为57.25μmol·mol－1；不同品种冬小麦CO2补偿点的最高值和最低值差值为49.82μmol·mol－1，说明华北地区冬小麦随品种演变CO2补偿点变化明显。建立了中国华北地区7个典型冬小麦品种包含CO2因子的直角双曲线光合作用模型，确定了不同年代不同品种冬小麦CO2的补偿点，为进一步建立包含CO2直接作用的气候变化影响评估机理模型提供基础数据。