半干旱区作物根系生长冗余的生态学分析

干旱是威胁农业生产的一个常见因子。在水分有限条件下，植物往往产生庞大的根系；这是自然选择的必然结果，是一个进化上稳定的生长对策（ＥＳＳ）。但作物产量是一个种群水平上的属性；个体的ＥＳＳ并不能优化整个群体的产量。我们提出在半干旱雨养农业地区作物受自然选择的影响在根系生长上往往失之于过快或过大，出现了“冗余”。通过育种或管理措施降低根系生长冗余可提高作物产量。

AN ECOLOGICAL ANALYSIS OF GROWTH REDUNDANCY IN ROOT SYSTEMS OF CROPS UNDER DROUGHT CONDITIONS

Drought is a common factor that threatens agricultural prduction,With limited water sup-ply,plants tend to produce an extensive rcot system,This is a necessary result of natural selec-tion,which is an evolutionarily stable growth strategy(ESS).But an ESS does not optimizecrop production,because crop yield is a population-level attribute.We propose that rainfed cropsin semiarid areas have an over rapid growth of rcot systems due to the influence of natural selec-tion,and root redundancy accrues,By means of breeding or appropriate management measureswe can decrease the root redundancy and increase crop yield.