Effects Of Foliar Application Iron On Growth And Iron Uptake Of Different Genotypes Winter Wheat (Triticum Aestivum L.)

Wheat is one of the mainr food of Northern people in China, the iron of wheat grain isalso a major source of iron needed by the body. By using fertilization to increase iron contentof wheat grain is a effective way to improve daily iron intaket, thus contributing to humanhealth concern. To explore the effects of the best periods of iron foliar application and selecthigh-iron genotype wheat, a pot plant experiment with14different wheat genotypes wasconducted during2008-2009growing season, foliar application iron was conducted at threedifferent level, include a control treatment (without iron), foliar application at jointing stageand filling stage of winter wheat. Field trials was carried out with25different wheatgenotypes during2009-2010growing season. There are three different iron levels include onecontrol treatment (without iron), foliar application at returning stage, jointing stage,flowering stage and filling stage of winter wheat. The main results are as follows:1. Both pot experiment and field trial results show that foliar application iron at differentstages of winter wheat can increased grain yield.2. Iron content in wheat grain were significant different for genetypes, the difference ofgrain iron content for highese variety is almost1.71times of lowest one in the potexperiment. While the grain iron content difference is most greatly1.5times amony differentgenotypes in the field trial. According to iron content and the response for iron application inthe pot experiment, all tested varities can be calssfied into two main types, YM34, LK2,XY503, XN889belong to high Fe genotype and H9511, PB202, PB151, ZJ attribute to low Fegenotype. In the field trial, all tested25gentypes can be divided into three category, amonythem ZM, XN9871, XY503, ZM19, XN889, LK2are high Fe genotype, QN142, S229, XY22,HM, PB151are middle Fe genotype and ZY9507, V9846, YN21, JN17are low Fe genotypeBoth pot experiment and field trial show that XN889is high Fe genotype.3. In the pot experiment, foliar application iron on jointing stage of different genotypesof wheat can both increase grain yield and iron content of grain. Iron fertilizer spraying indifferent periods could increase the units of different genotypes of wheat spike, while grainnumber and grain weight difference was not significant. Distribution of iron in differentorgans of wheat showed the proportion as the order: root>leaf, glume, stem>grain, rachis; in other words iron mainly accumulatedin the roots. Whether or not iron foliar application, rootsand rachis biomass in low-iron genotypes of wheat is greaterthan that in high iron genotypes;on the contrast, iron content of grain in high-iron genotype wheat was higher than that inlow-iron genotype wheat. Jointing stage is the best period for iron fertilizer spraying.4. In the field trial, the jointing and flowering stages of foliar application in differentwheat genotypes can increase photosynthetic rate of wheat leaves. Foliar application iron canrasie wheat grain yield of high iron wheat genotypes, however, which result in the decreasingof the iron content in grain. For low iron Wheat genotypes, iron fertilizer spraying canincrease both wheat production and the iron content in wheat grain. The jointing stage offoliar application can increasethe grain weight of low iron wheat genotypes significantly, theflowering stage of foliar application can significantly improve the grain number of high ironwheat genotypes, and the filling stage of foliar application can significantly increase irongrain number of low iron wheat genotypes. The stage of foliar application and wheatgenotypes had no significant effect on spike numbers per area.5. Different genotypes of wheat have different response for the same period of spraying.Spraying iron fertilizer has a increased trend on grain number of QN104, XY503and PB202gentypes, thus significantly increase the grain weight of these three genotypes of wheat. Onthe contrast, the unit spike and plant height had decreased somewhat. However, differencesbetween the various genotypes was not significant.The iron content in different organs of wheat growing period goes on, stem, leaf, glumeperformance of the same law of the iron content, showing maturity stage>filling stage>flowering stage, while the grain iron content of is filling stage application is biggerthanmaturity. As wheat growth stage, leaf iron accumulation in the proportion of the upperpart of total iron gradually decreased and glume iron accumulation increased, little change inthe iron stem. From seedling stage to maturity, wheat shoot iron accumulation graduallyincreased to peak at ear bearing stage. Iron in the early growth stage of wheat was mostlyaccumulated in the leaves, while that transferred to the leaves in the glume at late growthstage of wheat.Spraying iron fertilizer increases iron accumulation ratio in wheat glume at mature stage,and it also can increase the proportion of iron accumulation in wheat grain at both the fillingstage and maturity stage of different genotypes wheat.