VARIATION FOR STARCH CONCENTRATION IN SPRING WHEAT AND ITS REPEATABILITY RELATIVE TO PROTEIN-CONCENTRATION

A major objective of Canadian spring wheat breeding programs has been to increase grain protein concentration and quality of cultivars relea sed for commercial production With the recent discovery of starch muta nts in wheat (Yamamori et al 1994), and their association with specifi c noodle-making quality (Miura and Tanii 1994) emphasis on manipulatin g the starch composition and quantity of Canadian wheats is likely to gain importance. Furthermore, the recent development of fully waxy end osperm wheat (Nakamura et al 1995) may create new opportunities for th e utilization of wheat starch in the food processing industry. High st arch content cultivars may become desirable for the production of grai n ethanol and biodegradable packaging materials (Wasserman et al 1995) . With the exception of soft white wheats, most Canadian wheat cultiva rs have been selected for elevated protein concentration with less emp hasis on selection for increased starch concentration. Selection of wh eat genotypes with increased starch concentration will require simple, yet repeatable methods to identify high-starch genotypes. There is a lack of published information regarding the repeatability of starch co ntent measurement across wheat cultivars and environments. The objecti ve of this study was to determine the variation in, and repeatability of, grain starch concentration relative to that of grain protein conce ntration in spring wheat.