棉花钾营养效率的基因型差异研究进展

 棉花属于喜钾作物，目前生产上因缺钾而导致的棉花早衰问题日趋严峻。不同棉花基因型的钾营养效率存在显著差异，本文综述了其研究现状，并从钾吸收和利用等方面分析了差异的机制，以期为棉花钾高效育种和栽培提供指导。钾吸收效率高的基因型通常根系发达、根毛较多或生理吸收能力较强（最大吸收速率I_max高、亲和常数K_m和维持净吸收的最小钾浓度C_min低）；钾利用效率高的基因型可实现有限钾的高效运转和再分配，且其生理生化代谢的最低需钾量较小、碳氮代谢较为平衡、清除活性氧的能力较强。文中还提出了需要继续研究的方向。

Review of Genotypic Differences and Underlying Mechanisms in Potassium Efficiency of Cotton ( Gossypium hirsutum)

Potassium(K) is a major plant nutrient with many biochemical and physiological functions.Cotton has a high demand for K.However,widespread K deficiency in cotton occurs in many countries.Cotton varieties differ in their K uptake efficiency.This review accessed the available literature on K uptake and utilization efficiency in cotton related to genotype differences.Genotypes efficient in K uptake may have a larger root system and/or efficient physiological uptake characteristics(such as greater Imax [maximum influx rate],and lower Km [the Michaelis constant] and Cmin [the minimum concentration for net uptake]).Furthermore,genotypes efficient in K utilization may have active K transport and remobilization,high net photosynthetic ability,better balance between carbon and nitrogen metabolism,greater ability to scavenge reactive oxygen species,and increased capacity to substitute Na+ for K+.Future research areas regarding K efficiency in cotton are suggested.