The Study On Dry Matter Accumulation And Other Main Traits Of Inverted Senescing Sequence Of Different Wheat Cultivars Under Different Fertility Levels

With Xinong2718, Wenmai19, Zhoumai22, CP9811, Wunong148, Xinongthe527,Shan229, Yumai19, Xinong88yu3,95H7ten different wheat varieties as testmaterial,experiment was carried out to study the effect of diffenert levels of fertilizer on thepercentage of inverted Senescing Sequence of Wheat Leaves and with eight of them tostudying the comparison between reverse sequence stem and conventional sequence stem ofleaf area,specific leaf weight,SPAD,photosynthetic rate,transpiration rate,,stomatalconductance,dry matter accumulation of different organs,yield and yield componentelements,which has provided an new approach to wheat breeding. The major findings are asfollows:(1)Varising in different wheat cultivars the Inverted Senescing Sequence of wheatleaves first found on12th May and reach its top on24th May or so. Fertility levels hassomething to do with the percentage of reverse senescing.(2)The SPAD value can show the percentage of inverted senescing sequence ofvarious species.With lower percentage of inverted senescing sequence,95H7,Xinong88yu3,Shan229,Xinong527have higher flag leaf SPAD value over2nd leaf;while with higherpercentage of inverted senescing sequence, Wenmai19, Zhoumai22, Yumai19andXinong2718have lower flag leaf SPAD value than2nd leaf. The average SPAD value ishigher in inverted sequence stem than in conventional sequence stem.The SPAD value offleag leaf in inverted sequence stem are lower than that of2nd leaf; The SPAD value of fleagleaf in conventional sequence stem are higher than that of2nd leaf.(3)In the late of the grain-filling stage,the Specific leaf weigh of inverted senescingsequence of various species is heavier than that of conventional sequence stem.the speed ofdecreasing of inverted senescing sequence is faster. The speed of decreaseing of Specific leafweigh of flag leaf is higher than2nd leaf in conventional sequence stem.(such asZhoumai22,faster by43.6%);For inverted sequence stem, the speed of decreaseing ofSpecific leaf weigh of flag leaf are slower than that of2nd leaf (such as Wenmai19,Zhoumai225.3%,2.9%slower). (4)In general, the photosynthetic rate,stomatal conductance,transpiration rate ofinverted sequence stem is better than conventional sequence stem.The mean photosyntheticrate,stomatal conductance,transpiration rate of flag leaf in inverted sequence stem is lowerthan that of2nd leaf. The mean photosynthetic rate,stomatal conductance,transpiration rateof flag leaf in conventional sequence stem is higher than that of2nd leaf.(5)Conparing between inverted sequence stem and conventional sequence stem of thesame wheat cultivar,the inverted sequence stem has larger leaf area,heavier dry matteraccumulation of ear,flag leaf,2nd leaf,remains and especially much heavier grains of theear and weight of a thousand seeds which means the inverted sequence stem has more drymatter accumulation.