Abstract: Study by physiological characteristics of maize inbred lines tolerant to low potassium from filling stage to maturity，investigate the physiological mechanism of maize resistant to low potassium，in order to provide a theoretical basis for the efficient maize breeding; Typical maize inbred lines tolerant to K⁺ deficiency(90-21-3) and sensitive to K⁺ deficiency(D937) as materials，through direct seeding in natural potassium deficiency field， determined the root morphology，potassium of different organs，leaves stay green，KUE，yield and related traits in the filling stage to maturity; Compared with the sensitive to K⁺ deficiency，the responses of maize inbred lines tolerant to K⁺ deficiency mainly in root dry weight and average root length increased by a big margin; Root volume， root surface area and the average diameter of root decreased by a small rate; Holding the number of green leaf area per plant，the relative small decrease in leaf area，chlorophyll content become more; Roots，leaves，ear in a slightly increased accumulation of potassium，in stem declined a little; Potassium content of leaves and leaf sheaths of a smaller decline，particularly clover leaf and sheath rod was the most prominent; A small decrease in ear dry weight，the length of no kernels ear increased slightly，the magnitude of yield reduction was small，potassium use efficiency was higher． Under Low potassium stress，maize inbred lines tolerant to K⁺ deficiency through increased in the average root length，to absorb more potassium in order to maintain the potassium content of leaf and sheath， ensure long duration of green leaf area，K utilization high，the distribution of potassium in more parts of organs to grain，to achieve grain yield as much as possible．

Key words: Tolerant to low potassium of maize inbred lines, Morph ological parameter of root , Potassium absorption, Stay green, Yield

CLC Number: 

• S513． 01

• S143．3