不同基因型小麦钾离子吸收动力学分析

Study on potassium uptake kinetics by different genotype wheat

在日光温室营养液培养条件下,研究了经筛选的不同钾效率基因型小麦在不同钾营养状况下K+的吸收动力学。结果表明,采用不同钾营养状况小麦K+吸收动力学参数Km和Imax对不同基因型小麦钾效率分类,结果与经筛选的不同基因型小麦的钾效率特征相一致,Km和Imax可用来评价和筛选高效吸钾基因型小麦。但不同基因型小麦Km和Imax在不同钾营养状况下表现规律不相同,Km和Imax值的大小受到小麦本身钾营养状况反馈调节,植物钾营养状况越高,Km越大,Imax越小;有的基因型受本身钾营养状况影响较大,有的受其影响较小,但总体上还是相一致的。结果还看出,温6-986和周麦13是钾高效基因型,予农015是钾低效基因型;同一基因型小麦在不同钾营养状况下是以不同机制吸收钾的。

The uptake kinetics parameters play an important role in screening nutrient-efficient genotypes since they could be used to evaluate the ability to uptake nutrient. The potassium uptake kinetics by different genotype under different K nutrition status was studied using greenhouse water culture. The results showed that there was a difference between the dynamic of depletion by different genotype wheat, and the depleting speed of efficient genotype was high while the speed of the inefficient genotype was low. K^＋ uptake kinetics parameters Km and Imax could be used to evaluate the differences of low K stress tolerant abilities for different genotype wheat. The results classifying with K^＋ uptake kinetics parameters Km and Imax under different K nutrition condition were corresponding with that of different K efficiency wheat screening. However, Km and Imax of different genotype wheat behaved differently under different K status, the value of which was influenced by the nutrition condition of wheat itself. With the increase of K level, the value of Km increased whereas Imax decreased, but some genotypes were influenced relatively largely and the others small, whereas there was still a law generally. W6-986 and ZM13 were potassium-efficient genotypes, and YN 015 was a kind of potassium-inefficient genotype. The same genotype wheat might uptake K^＋ with different physiology mechanism under different K nutrition status.