Improvement in wheat quality during the past ten years at CIMMYT; achieved while retaining high yield.

摘要

Bread making quality-related data from the International Bread Wheat Screening Nursery (IBWSN) spanning the period 1991-2000 was compared. The IBWSN consists of 200-400 new bread wheat lines, developed for irrigated wheat production. The IBWSN is distributed globally to more then 150 cooperators. Since its inception in the mid 1960's, IBWSN emphasized yield, yield stability, disease resistance, and lodging tolerance. Prior to the 1990's grain quality was a secondary priority. This reflected the needin developing countries during that period for quantity over quality. However, in the past 10 years several developing countries have legislated high quality as a requirement for varieties commercial production, reflecting a change in consumer preference. Therefore, starting in the early 1990's, most crosses made at CIMMYT included at least one parent with high quality. The new advanced lines emanating from this strategic shift express improved quality. Changes in quality include increased dough mixingtime and stability, dough strength and extensibility, and bread loaf volume. This improvement in quality is partly explained by the increased frequency of the Glu-Dl HMW glutenin subunits 5+10 in newer materials. At the same time yield levels increased (up to 0.07%/year) while the protein percentage of the grain remained constant. Therefore the gluten protein quality rather than its quantity increased.