Effect Of Sulphur On Gliadin And Glutenin Macropolymer Accumulation And Its Relationship To Grain Quality In Spring Wheat

The studies were carried out in Wheat Lab of Northeast agricultural university in Harbin from 2001 to 2002. The 5 cultivars in spring wheat differing in quality were used in the studies in different amount of nitrogen and sulphur application. The studies aimed at the formation and accumulation of gliadin and GMP, aimed at effect of sulphur on the formation and accumulation, as well as relating to the quality. The results showed:The initial amount of the four-gliadin fractions accumulation (10th day after anthesis), accumulation intensity and the final accumulation level were different in the cultivars differing in quality. The initial and final accumulation amount and intensity of α -gliadin were very low. The accumulation of β - and y -giladin differed with the cultivars. The initial amount of ω -gliadin was high, but its accumulation decreased with the development of grain filling.The applying sulphur had the role of regulation on the gliadin fractions, but the regulation must base on the amount of nitrogen amount. Under the condition of urea 30kg/hm2 or 60kg/hm2, the effects of applying sulphur on the β-, γ - and ω -gliadin in the cultivars used in the studies were positive, but the effects on the α -gliadin was positive mainly.The formation and accumulation of gliadin fractions determined by the genotype of cultivar, but it is very beneficial to the formation and accumulation of s-rich gliadin bands by applying sulphur under the condition of certain amount of nitrogen application.In all level of nitrogen and sulphur, the effect of the changes of gliadin fractions was small on the grain protein content and wet gluten content and SDS-sedimentation value.The trend of dynamic accumulation of GMP in the cultivars differing in quality decreased mainly during the period of grain filling.The initial and final accumulation amount of GMP in all cultivars was different, but the accumulation of GMP decreased fast within the 25 to 30 days after anthesis. The final accumulation amount was lower than that of initial accumulation in all cultivars used in the studies.Applying sulphur regulated GMP of different cultivars, and the regulation was related to the cultivars differing in quality and the amount of nitrogen application. The applying sulphur was not beneficial to the accumulation of GMP in the cultivars with high grain protein contentunder the condition of urea 60kg/hm2. Under the condition of urea 128kg/hm2, it is very beneficial to increase the GMP in Neepawa and Liao10 with high grain protein content by applying sulphur, but the effect of applying sulphur on the GMP in NKH9 with low grain protein was negative, and on the GMP in NE7742 and Roblin with high grain protein was a little.Whether in high level of nitrogen or in low level, with the amount of sulphur increasing, the GMP of NE7742 decreased, but benefit to the increasing of the grain protein content, wet gluten and SDS-sedimentation value. The same result found in Roblin and NKH9 in high level of nitrogen, yet, in low level of nitrogen, the correlation between the GMP content and the grain protein content was positive, as well as between the GMP content and SDS-sedimentation value.