| Based on the analysis of gliadin and glutenin for near-isogenic lines, five pairs NILs (2+12/5+10) in differing property of poor, medium, strong and super-strong gluten, and three NILs, which contain the special spectrum variance of gliadin, were chosen and used in the study. The studies were carried out in a randomized arrangement experimental design with 4 replicates grown in field both in 2002 and 2003, and pot experiment also carried out in 2003. The objective of the study was to investigate the difference of quality between NILs HMW-GS 2+12 and 5+10, the effect of high-nitrogen application on qualities of NILs HMW-GS 2+12 and 5+10, and the dynamic accumulation of protein and components of each NIL, as well as the change of glutenin subunit and gliadins.The result showed that both the bands of glutenin and gliadin in 5 pairs of NILs 5+10 subunit and its biotype 2+12 were completely identical. It also indicated that the accumulation patterns in total grain protein, structural protein, gliadin and glutenin were the same between two kinds of NILs subunit in same cultivar. No significant difference of component content between two groups of subunits was found. Initial time of HMW-GS and LMW-GS was the same as that of their biotype 2+12. But the relative content of HMW-GS changed in cultivars used. The ratio of LMW-GS/HMW-GS changed and the dynamic patterns were not the same in different NILs and the two different HMW-GS 2+12 and 5+10 during developing period of grain except Longmai20. The LMW/HMW ratio of 5+10 subunit in Longmai20 was lower than that of 2+12 subunit of the others at mature time. The bands of gliadin between 5 NILs were different, but the same when compared in same cultivar except Longmai 20. The initial time of γ gliadin in type 5+10 subunit was later than that of its biotype 2+12 subunit in Longmai 20. The change of gliadin of two subunits was identical for the other four cultivars, but the relative contents were different.The effect of 5+10 subunit on the quality index of cultivar with super-strong gluten was the same as those with weak and medium. The effect was mainly on the aspect of significantly increasing resistance of extensibility and extending area. But 5+10 subunit had the negative effect on water absorption of all provided flour samples, which contain different gluten in intensity. Statistical analysis of flour and processing quality indices based on the data obtained in two-year experiment with 4 replications on five pairs of NILs further confirmed that after 5+10 subunit replaces 2+12 subunit, the other quality parameters changed except protein content and dry gluten under the different genetic background. Whereas, the study showed that the effect was restricted markedly by genetic background and environmental condition.In this study, 5+10 subunit significantly increased the Zeleny sedimentation value under low protein content, but decreased or so much as no significant effect was found when the protein content was higher. The effect of 5+10 subunit on decreasing wet gluten content wasinfluenced by circumstances. As to the effect of 5+10 subunit on farinogram, the genetic background of genotype and the circumstances were the most remarkable factors influenced on it Comparing all farinograph parameters, the most stable effect is on the decrease of softening and water absorption, and then the effect on prolonging the broken time and stability time. The effect on developing time and valorimeter value was very complicated. Therefore, the effect of 5+10 subunit on baking-quality improvement depended on the gluten intensity, sedimentation, protein content and other quality background of the provided materials. No significant effect on cultivars with strong and super-strong gluten was found in the study. Meanwhile, 5+10 subunit had the most remarkable effect on extensibility index improvement, but genetic background and environmental factors the least.When the protein content was between 15% and 20%, the Glu-Dl loci variation still influenced a great number of quality parameters. After 5+10 subunit replacing 2+12 subunit, improving effect on wet gluten, wet gluten/dry gluten, gluten index, stability time, broken time and degree of softening in the five cultivars with weak-, medium-, and strong-gluten was still remarkable. However, different subunits in different cultivars had not the same reaction to high-nitrogen on different quality index.The trend of GMP content showed increase in 5+10 subunit type of 5-pair NILs when compared with that of 2+12 type. The correlation between GMP content of the various NILs and processing index of flour was mutative. In these two subunit groups, the positive correlation to protein content was significance at 1% level. And that to Zeleny sedimentation value varied from not apparently to markedly with the increase of protein content. For the positive correlation to wet gluten and dry gluten, 5+10 subunit group was more markedly than 2+12 subunit group in low protein content. While both of them showed significant correlation along with the increase of protein content. To wet gluten/ dry gluten ratio, only under the condition of protein content in pot experiment, the negative correlation of 5+10 subunit could be at 1% level of significance. The GMP content of both these two subunit groups could indicate the change of flour Theological index. There was the remarkable relationship between GMP content and development time, stability time and broken time, and the correlation coefficient of different subunit groups was changeable under different cultivated conditions. These two subunit groups showed significant effect on maximum resistance of extensigraph and extensigraph area, but no effect on extensibility.This research discovered a new line that there are three special gliadin bands, Rm20.5, Rm22.8 and Rm50+, in Longmail9 5+10 lines. And these three bands were in same position as Marquis (the 5+10 subunit donor) electrophoretic bands. According to preliminary judgment, these three bands were original from Marquis. The subunit 2+12 type, 5+10 subunit type and 5+10 adding gliadin special bands, i.e. Longmai 19 (5+10+3R) of selected Longmail9 are ideal materials for studying the effect of special gliadin on processing quality of flour. It confirmed that the simultaneous appearance of R20.5, R22.8 and R50+ bands hadlittle effect on protein content and dry gluten content. But the negative effect of the three special gliadin bands on Zeleny sedimentation value almost counteracted 5+10 subunit positive effect. The special bands of giiadin showed negative effect on wet gluten, wet gluten/dry gluten ratio, gluten index, and flour quality index. While this negative effect was variable between years. Gliadin R20.5, R22.8 and R50+ also had negative effect on extensigraph parameters, but this effect was relatively not apparent when compared with the positive effect of 5+10 subunit.
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