耐低钾玉米自交系灌浆至成熟期生理特性研究

Physiological Characteristics of Maize Inbred Lines Tolerant to Low Potassium from Filling Stage to Maturity

研究耐低钾玉米自交系灌浆至成熟期的生理特性,探讨其耐低钾的生理机制,为钾高效玉米育种提供理论依据。以多年筛选出的典型耐低钾玉米自交系90-21-3和典型不耐低钾玉米自交系D937为试材,在天然低钾土壤上进行田间试验,于灌浆至成熟期测定根系形态、叶片持绿性、各器官的钾素积累量、钾利用效率、产量及产量性状。与不耐低钾玉米自交系相比较,低钾胁迫下,耐低钾玉米自交系主要表现为平均根长增加幅度大;根体积、根表面积和根平均直径下降幅度小;持绿叶片数、单株绿叶面积、相对绿叶面积的下降幅度小;叶绿素含量增加;根、叶、雌穗中的钾积累量略有增加;茎中的钾积累量下降幅度小;各叶片和叶鞘的钾含量下降幅度小,尤其棒三叶的叶片和叶鞘表现最为突出;雌穗干质量下降幅度小;秃尖长没有增加,产量降低的幅度小;钾素利用效率高。耐低钾玉米自交系在低钾胁迫下平均根长增加,各叶片和叶鞘中的钾含量较高,干物质积累较多,绿叶面积大,绿叶面积持续期长,叶绿素含量高,钾素利用率高,籽粒部位器官钾素含量较多,产量较高。

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.