Studies On Differences In Potassium Nutrition Of Wheat Genotypes

The essay studied the characters of potassium nutrition of four wheat genotypes in flowering and maturity stage. The results obtained are as follows: (1) The genotypes with high absorption ability of potassium is not probably high in use efficiency. It is essential for the plant to get a proper potassium accumulation. Judging the tolerance to low potassium level depends on not only the accumulation but also grain yield, it will be better when the both are high. (2) Judging the characteristic of the tolerance to low potassium level according to the potassium biological availability, the variety of Lankao 906 is the good one among the tested varieties: when judging with potassium use efficiency as standard, Wenmai 6 and Yanzhan 1 are the good ones with high efficiency; when regarding with potash use efficiency as basis, Wenmai 6 is the right one with excellent respond to potash; (3)There is significant positive correlation between economic output and potassium content and accumulation in ear shell and root in mature stage while the correlation betweem potassium content and potassiumaccumulation in stem and leaves are not. (4)There is significant positive correlation between potassium economic efficiency and potassium utilization rate in flowering stage, and it is consistent to judge wheat potassium efficiency by potassium use efficiency in flowering stage and potassium economic efficiency in mature stage . (5)Potassium accumulates mainly in stem and leaves and only small part is in grain in mature stage, while Nitrogen and phosphate distribute in the opposite tendency. (6)There is negative correlation between grain weight and nitrogen content and i ts accumulation in stem and leaves . It indicates that the nitrogen in grain is mainly supplied by stem and leaves. Increased potassium content can help nitrogen transport from stem and leaves to grain, which Increased the wheat grain output accordingly. (7) The nitrogen levels in stem and leaves of Yanzhan 1 and Wenmai 6 are low while they are relatively high in grain, which shows that the reason the two varieties absorb potassium more efficiently is that they have a stronger ability of reusing the nitrogen in stem and leaves. (9)There is significant positive correlation between the ratio of N/K and potassium use efficiency in wheat mature stage. The genotypes with high potassium use efficiency have definitely high nitrogen use efficiency.