Formation Of Ash And Its Relation With Processing Quality In Wheat

To investigate the differences of ash content among genotypes and the relationship of ash content to nutritional and processing quality, the effects of fertilization on the content and accumulation amount of ash, and the effects of cultivation techniques on the contents and accumulation amount of Fe and Zn in wheat for different end uses, 32 wheat varieties were used as test materials. The experiment was carried out on the experimental field of Crop Cultivation and Physiology Key Lab of Jiangsu Province ,Yangzhou University from 2002-2004.The main results were as follows.1 Changes of ash content and accumulation amount in different wheat genotypesAsh content and accumulation amount in grains, flour, bran differed significantly among different genotypes. The variation order of ash content in different parts of grains was flour > bran > grain, for ash accumulation was flour > bran > grain.Ash content in grains decreased gradually after anthesis. The decline rate was great before the 20-25~thday after anthesis (DAA). Logistic equation could match the changes of the ratio of accumulated ash to final ash amount in grains with days after anthesis.2 Relationship of ash content to grain exterior characters, nutritional and processing qualityThe correlation of ash content to grain type, grain color and vernalization characteristics was not significant. Ash content in grains and flour was significantly related to kernel texture and significantly positively related to the ratio of length to width.Ash contents in grains and bran were negatively related to flour whiteness, and ash content in flour was significantly negatively related to flour whiteness. Ash contents in grains and flour were significantly positively related to protein content, dry and wet gluten contents, zeleny sedimentation volume. Ash content in grains was negatively related to starch content.3 Effects of fertilization on ash content and accumulation amount in wheat for different end usesAsh content and accumulation amount in grains and flour could be increased by applying nitrogen fertilizer. The ratio of basal: top dressing N could significantly affect ash content and accumulation amount in grains and flour.Nitrogen applying amount and the ratio of basal: top dressing N could affect the dynamics of ash content. Ash contents in the treatments with nitrogen fertilizer were higher than that in control after anthesis. The effect of nitrogen applying amount on ash content was not significant at early stage. After 21st DAA, ash content in the treatment with great nitrogen applying amount were higher than those with low nitrogen applying amount. The differences of ash content among the treatments with different N application methods were not significant at early stage, but became more and more significant after 14th DAA. Ash content in the treatment with more top dressing N decreased greatlier than that with less top dressing N.The ratio of N^OsrKaO could significantly affect ash content and accumulation amount in grains and flour.4 Effects of cultivation techniques on the content and accumulation amount of Fe and ZnThe contents and accumulation amount of Fe and Zn in grains and flour were significantly different among genotypes. Fe content was greater than Zn content, Fe and Zn content in bran were greater than those in grains and flour. The content of Fe in grains after anthesis showed "M" type change while the content of Zn increased at first then decreased. The varieties with high ash content and accumulation amount normally had high content of Fe and Zn in grains and flour which were beneficial to people's health.When the percentage of top dressing N raised, the content and accumulation amount of Fe in grains increased, the contents and accumulation amount of Fe and Zn in flour increased, the content and accumulation amount of Zn in bran increased, the ratio of Zn distributed to flour increased too.When top dressing phosphor postponed, the contents and accumulation amount of Fe and Zn in grains increased. The content of Fe and Zn in flour increased too, bu...