Abstract:

Grain hardness, controlled by hardness gene (Ha) on the short arm of chromosome 5D, is one of the most important quality characteristics and serves as a basis for classification and marketing of bread wheat (Triticum aestivum L.) quality. A total of 41 wheat cultivars (lines) from Chinese spring wheat region and CIMMYT were used to investigate variation of SKCS hardness index, puroindoline alleles, milling yield, flour ash content, water absorption, flour color (L*, a* and b*), total pentosans and water-soluble pentosans contents, steamed bread and noodle processing qualities. Five Pina-D1a/Pinb-D1a (wild type), 28 Pina-D1b/Pinb-D1a, seven Pina-D1a/Pinb-D1b and one (Qingchun 533) Pina-D1a/Pinb-D1c genotypes were observed in surveyed wheats. Grain hardness showed significantly positive correlation with water absorption (r=0.80), while significantly negative correlation with flour brightness L* (r= －0.77). Means of SKCS hardness index, milling yield, water absorption, and steamed bread weight, volume, width and total score in genotypes with mutational puroindoline allele were significantly higher than those in wild type. Means of SKCS hardness index, flour ash content, flour a* absolution value and water-soluble pentosans content in genotypes with PINA null (Pina-D1b/Pinb-D1a) were significantly higher than those of Pina-D1a/Pinb-D1b, while surface score of steamed bread and firmness of noodle is significantly lower than those of Pina-D1a/Pinb-D1b. In addition, means of noodle brightness L*, L*－b* value and firmness in wild genotype (Pina-D1a/Pinb-D1a) were significantly higher than those in PINA null (Pina-D1b/Pinb-D1a) type, while surface color of steamed bread and yellowness of noodle was significantly lower than those in PINA null type. This indicated that the performance of steamed bread and noodle from Pina-D1a/Pinb-D1b type is slightly superior to that from wild type and PINA null. This study provides useful information for improving Chinese wheat quality.

Key words: Common wheat, Puroindoline gene, SKCS hardness index, Milling quality, Pentosans content, Steamed bread quality, Noodle quality