Abstract:

Starch pasting properties, one of the major factors influencing the quality of Dry White Chinese Noodle, is great affected by Wx-A1, Wx-B1 and Wx-D1 protein subunits, among which Wx-B1 null makes the biggest contribution. In order to detect new gemplasm to improve the quality of Chinese noodles, four hundred and eighty-eight spring wheat lines from CIMMYT 35th International Bread Wheat Screening Nursery (35th IBWSN) and 20^th Semiarid Wheat Screening Nursery (20^th SAWSN) were collected and planted in Linhe, Inner Mongolia in 2003. Samples were harvested to identify their Waxy protein subunits and the relationship with RVA (rapid viscosity analyzer) parameters. 191 lines with Wx-B1 null subunit and 28 lines with Wx-D1 null subunit were identified by SDS-PAGE. The results indicated that final viscosity and set back of lines with subunits of Wx-B1 null and Wx-D1 null were significantly higher than those with normal Wx protein subunit, while peak viscosity and break down of Wx-D1 null lines were significantly lower than those of normal Wx lines, peak viscosity and break down of Wx-B1 null lines were significantly higher than those of Wx-D1 null lines. Significant variation among the lines for RVA parameters except for peak time was also observed. Compared with China’s spring wheat, the CIMMYT spring wheat lines expressed higher peak viscosity, though viscosity, final viscosity, larger break down and set back, as well as longer and stable peak time. RVA parameters for lines from 35thIBWSN were much higher than those from 20^th SAWSN.

Key words: Triticum aestivum L., Waxy protein subunit, Rapid viscosity analyser, Starch pasting characteristic