Varietal Differences And Cultivation Regulation Of Zn Absorption In Wheat Plant

Micronutrient concentration in wheat grains is crucial for the plant growth and people’s dietetic health.Higher micronutrient concentration in grains is beneficial to improve nutrition character of grains andguarantee the security of crop products. With the wheat cultivars in Henan Province as experimentalmaterials, analysis on difference of grain Zn content in different wheat genotypes. Study on absorption,distribution and accumulation of Zn in over-ground plant were discussed. Study on the cultivation controlmeasures on the wheat plant Zn uptake and accumulation, growth physiology and yield, The mainexperiment results were as follows:1. Concentration of Zn in grains appeared downtrend from7d to21d after the flowering stage,andincreased rapidly from21d to35d after flowering stage. The relationship of Zn concentration in grains(y)and days after anthesis(x) could be described as quadratic equation which was y=0.0679x2-3.7479x+96.312.The accumulation of Zn in grain increased rapidly from7d to14d and21d to28d after theflowering stage, while increased slowly from14d to21d and28d to35d.With the grain filling, Theaccumulation of Zn in grain(y), and days after anthesis (x) could be described as quadratic equation whichwas y=0.0527x2+0.0941x+0.1292.2. There had significant difference of Zn concentration、dry matter accumulation and Zn accumulationin grains among genotype. Concentration of Zn in grains ranged up to1.99times, the coefficient ofvariation of29.34%; dry matter accumulation of grain changes within1.5times, the coefficient of variationof13.05%; Zn accumulation of grain ranged up to2.36times, the coefficient of variation of41.31%; Theallocation ratio of grain dry matter accumulation performance Zhou mai22> Lan kao ai zao8> Yu nong202> Yan zhan4110> Yu mai49-198. The distribution rate of Zn in grain performance Lan kao ai zao8>Yu nong202> Yumai49-198> Zhoumai> Yanzhan4110, And the highest distribution rate up was foundin Lan kao ai zao8, which was67.93%, significantly higher than the other varieties.3. Zn concentration of wheat organs was4.22to174.98μg g-1from early filling stage to mature stageunder exogenous Zn treatments. And Zn concentration in leaves tended to be the highest among all theorgans. The variation of Zn concentration was mainly due to exogenous Zn, while the effects of variety andthe interaction of variety×exogenous Zn should not be neglected. Exogenous Zn application could enhance the accumulation of dry matter of wheat significantly. However, excess Zn fertilizer could lowerdry matter accumulation. In this paper, Zn concentration of200mg kg-1was the most appropriate level tothe accumulation of dry matter. The total Zn accumulation amount in wheat enhanced with the increase ofexogenous Zn level, and the order of Zn accumulation amount could be described as Zn8>Zn4>Zn2> Zn0.In early filling stage, Zn accumulation in leaves was the highest. In mature stage, about50%of Znaccumulation in wheat was distributed in grains, and Zn accumulation in roots and grains was increasedsignificantly by exogenous Zn application. Among these4treatments, Zn distribution ratio in grains wasthe highest under Zn2treatment.4. Zn-N interaction can improve SOD activity, reduce the CAT activity of seedling wheat. Theinfluence of Zn treatment reached extremely significant level (P <0.01) on CAT activity and Pn of flagleaf at5days after flowering stage, SOD activity of flag leaf at25days after flowering stage, SOD activityof grain at5days after flowering stage, POD and CAT activity of grain at25days after flowering stage.The adequate Zn promoted the SOD, POD, CAT activity and Pn of flag leaf after flowering, improved theSOD、POD activity of grain at5days after flowering stage and POD activity of grain at25days afterflowering stage, reduced the CAT activity of grain after flowering. Along with the development of wheat,the photosynthetic rate of flag leaf was decreased, stomatal conductance was decreased after the first andthe intercellular carbon dioxide concentration and transpiration rate showed an increasing trend. Znconcentration of200mg kg-1was the most appropriate level to the photosynthetic rate and yield. Thephotosynthetic rate and yield reduced with Zn concentration of800mg kg-1.5. Nitrogen increased Zn concentration of grain, Zn concentration was higher in the two waterconditions and N supply with120kg·ha-1, the three water conditions and N supply with180kg·ha-1. wereZn accumulation of grain increased with moderate N supply, too much or too little of N is not conducive tothe Zn accumulation of grain, The distribution rate of Zn in grain is higher when N supply with120kg·ha-1.