Effects of Exogenous Zn on Zn Absorption and Accumulation of Winter Wheat at Later Growth Stage

In order to study the effects of exogenous Zn on Zn absorption and accumulation of winter wheat in later growth stage,pot experiments were arranged in green-house during 2009-2010 with experimental materials of Zhoumai-18 and Aikang-58,two popular wheat varieties at present in Henan.Zn concentrations in cultivating soils were 4 levels of 0,200,400 and 800 mg·kg-1,and indicated as Zn0,Zn2,Zn4 and Zn8,respectively.Zn concentration and dry matter weight in different organs in early filling stage and mature stage were measured to calculate the Zn accumulation amount and distribution ratio.The results indicated that Zn concentration in wheat organs ranged from 4.22 to 174.98μg·g-1,and Zn concentration in leaves tended to be the highest among all the organs.The variation of Zn concentration in organs was mainly due to exogenous Zn treatment,while the effects of variety and the interaction of variety × exogenous Zn would not be neglected.Exogenous Zn application could enhance dry matter accumulation in wheat significantly.However,excess Zn fertilizer lowered dry matter accumulation.In this paper,Zn concentration of 200 mg·kg-1 was the most appropriate level to the accumulation of dry matter.Total Zn accumulation amount in wheat enhanced with the increase of exogenous Zn level,and the order of Zn accumulation could be described as Zn8 Zn4 Zn2Zn0.In this experiment,Zn accumulation in wheat of Zhoumai-18 was higher than that in Aikang-58.At early grain-filling stage,Zn accumulation in leaves was the highest.At mature stage,the main organs of higher Zn distribution ratio were grains and roots.And about 50% of Zn accumulation in wheat was distributed in grains,the distribution ratio of Zn in grains tended to be the highest under Zn2 treatment.From the above,appropriate Zn application in soils could promote the accumulation of dry matter and Zn,and it was benefit for grain yield and quality of wheat.