Genotypic And Environmental Effects On Rutin And Protein Contents In Buckwheat Grain

Buckwheat, a crop adapted to cool, moistc climates and short growing season, belongs to the Polygonaceace family, botanically divided into two main categories: Fagopyrum tararicum Gaerth and Fagopyrum esculentum Moench. Buckwheat, especially tartary buckwheat, contain a high content of a bioactive substance—rutin. No rutin has been detected in other cereal crops. Buckwheat also contains protein with high biological value and balanced amino acid composition. In order to provide foundation for scientific management and production of high quality buckwheat, firstly, 66 cultivars from different location of China were evaluated on rutin contents to screen buckwheat genotypes with high rutin contents in grains. Secondly, the effects of temperature, sowing date, seeding density, fertilization and planting district on contents of rutin, protein, protein components in grains and sprouts, the dry weight of plant and yield were studied in this paper.The main results are shown as follows:1. The genotypic variation of rutin content in buckwheat grainThere were significant differences in contents of rutin, protein and protein components in grains of not only between two buckwheat categories, but also among different cultivars within same categories. In this study, rutin contents in grains showed a wide range of variation, from 0.63% to 2.03% among 46 tartary buckwheat cultivars collected from different areas of China, with a mean of 1.184%. Rutin contents of 22 common buckwheat cultivars varied from 0.0051% to 0.0301%, with a mean of 0.0174%. Rutin contents of 47% of tartary buckwheat cultivars were between 1.15% and 1.5%. Rutin contents in grain changed from 0.0051% to 0.013% among half of common buckwheat. The mean of total protein content in grains of tartary buckwheat was higher than that of common buckwheat. In protein components, albumin content was the highest, and the range of albumin content variation was the widest, and prolamin content was the lowest.2. Effects of temperature on rutin contents in seedlings, leaves and seeds of buckwheatThe rutin content of buckwheat seedlings were significantly higher than that of seeds andwere decreased with the increasing of incubation temperature. The rutin contents of leaves and of seeds were increased with the increasing of culture temperature at grain filling stage in this experiment.3. Effects of sowing date and seeding density on contents of ruin, protein and protein components in tartary buckwheat grainThe effects of sowing dates and seeding density on contents of ruin, protein components in grains and sprouts, and yield of Liuku 3 , a tartary buckwheat variety, were studied and the results results were as followed as: Contents of rutin, albumin, glutelin and total protein in grains decreased with the delay of sowing date. Contents of prolamin and globulin were not significantly affected by treatments. It illuminated that sowing date advanced properly can improve contents of rutin, protein, protein components and yield. Rutin contents in grains were no statistically significant differences within the scope of density of 60xl04~90xl04per ha. Rutin content would decrease when the density was over 90xl04 plants per ha. With increasing seeding rate, contents of albumin, globulin and total protein, the dry weight of different organs and yield gradually decreased. Seeding density had essentially no impact on contents of glutelin and prolamin.4. Effects of fertilizer application on contents of ruin, protein and protein components in buckwheat grainDifferent nitrogen application level and N, P, K combined application were all statistically significant influenced the rutin content in grains and the PAL activity in leaves. With increasing amounts of nitrogen application, the rutin content and the PAL activity were improved. When the amount of nitrogen application was 225kg per ha, the highest values were determined. But excessive nitrogen applied caused the decrease of rutin content and the PAL activity. The rutin content and the PAL activity in NPK combined application treatment were higher than that of NP, NK, PK and CK treatments. Changes of values of the rutin content and the PAL activity were consistent among all treatments. The changing trends in rutin contents were rather similar as PAL activity, which indicates that the tutin content was closely correlated with the PAL activity. The increase of the albumin content was the highest than that of other protein components with increasing amounts of nitrogen application. Other environmental conditions had a much largerrelative contribution to the variation in globulin content than nitrogen application treatments. So changes of globulin content were consistent in tow years. Glutelin contents were improved with increasing nitrogen amounts, but the variations were not significant among treatments. The increase of total protein contents in NKP combined application were the highest than that of NP, NK, PK and CK treatments. Compared with phosphorus and potassium, nitrogen played an important role in contents of total protein and protein components in buckwheat grains. So, appropriate nitrogen amounts or NKP combined application improved contents of total protein and protein components in buckwheat grains significantly.5. The location variation of rutin content in buckwheat grainGenotypic and environmental variations in grain rutin, total protein and protein components contents were investigated by two tartary buckwheat genotypes and two common buckwheat genotypes, planted in Chifeng city of Ganshu province, Baoji city of Shuanxi provice and Taixing city of Jiangsu province. The results showed that the interaction of cultivar and location was highly significant for rutin contents of two categories grains. Cultivar and location had no significant differences of rutin contents. In common buckwheat grains, location and the interaction of cultivar and location was highly significant for albumin content, with the location having the larger effect, variation of other protein contents were only due to the interaction of cultivar and location. In tartary buckwheat grains, the interaction of cultivar and location was the only significant source of variation for contents of albumin and globulin, location and the interaction of cultivar and location was highly significant for total protein content in tartary buckwheat grains. The effects of cultivars, locations and their interactions on contents of prolamin and glutelin did not play significant roles. The highly significant interaction between cultivars and environments suggests that it is important for buckwheat to be planted in optimum districts.