| Gliadin. the major storage protein in endosperm, affected quality in spring wheat b}' itscontent and composition. The fractions of gliadin played different role in wheat quaIit}.Reports on the fOrmation and accumulation of fOur gliadin fractions were rareIy found. Thenitrogen tbrtilizer application could improve quality in wheat, but the role of different kindsof nitrogen fertilizer might be not identical. The studies aimed at the accumulation of gliadinand four fractions and nitrogen regulation, as well as relating to the quality. The studies werecarried out in Harbin from 2000~200l, and 18 cuItivars differing in HMW-GS compositionweTe used.The results showed that the content of gliadin in grain increased gradually along withthe process of grain-filling. and reached the maximum in mature. The initiation of g1iadinwas nearly at the same time in cultivars used in the study. But the intensity and final contentdiffered evidentl}' with HMW-GS composition, and cultivars with 7+9 and 2+12 had srna1leraccumu1ation intensity and lower final content. During grain-filling, all of four g1iadinfractions had the same increase trend. but differed in initia1 amount (10 days after anthesis).accumulation intensity and final accumulation level. In most cultivars used in the stud}', theaccumulation rate of Q -gliadin showed in low leveI at the beginning of itS initiation. ]owintensit}'. and 1ou' final accumulation rate. and accumulated rapidl}' in late duration ofgrain-filling, so as to have the highest final level even though the accumulation of Y - andto - gliadin diffeho with culhVarS.Different gliadin composition in different genotypes was obtained by A-PAGE, even ifwith the sarne HMW-GS composition. The difference ofgliadin composition betWeen foreignand local cultivars used in the stUdy focused on y - and to -region mainly. The resultindicated that al1 cultivars possessed the same bands of Rm50 and dri60.6, but bands Rm24and dri83, maybe relating to good qtality only existed in cultivars Liaol0, Roblin, Neepaw4LM26, NES34, NES25, NES57 and NEcv8542, and Roblin, NE7742, NESl8 and NE7757,respectively. The bands in co -region initiated earlier than that of in Q -region. The intensity ofeach band increased along with the grain development until maturity.The dynamic trends of gliadin accumulation were the same in different nitTogentreatments but difference in regulating initial amount, accumulation intensity and final levelof accumuIation, and varied with cultivars. Of the three Nitrogen fertilizer toes, theamide-form nitrogen source was more propitious to the formation and accumulation of gliadin, as well as its four fractions.Different cultivars not only differed in final accumulation of gliadin fractions, but also the ratio of each fraction to total amount. The ratio of Y -gliadin to total gliadin was highest in NE7742, NES18, NES57(with 2 and 12 subunit ), Pavan and Longmai26 (with 5 and 10 subunit), but to -gliadin in NES250 with 2 and 12 subunit, Roblin, LiaolO and Neepawa with 5 and 1 0 subunit.Accumulation of gliadin and its four fractions, especially the total gliadin, P -gliadin and " -gliadin, was positive relation with protein content, wet and dry gluten contents. Amount of v -gliadin was positive with both gluten index and SDS-sedimentation value. Correlation between gliadin (total and fractions) and several quality indexes was different in cultivars with HMW-GS composition. In 2+12 HMW-GS composition, the positive correlation coefficients were significant statistically between gliadin and protein content, wet and dry gluten, but only found between gliadin and gluten index and SDS-sedimentation value in cultivars with 5+10 HMW-GS composition.Both gliadin and SDS-soluble glutenin increased along with grain-filling. The ratio of them to quality indexes was not close, and the amount of them was positive with protein content, wet and dry gluten content, but negative with gluten index and sedimentation value especially in...
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