A technique is described for the selection of low extractable non-starch polysaccharide content in early generations of barley breeding programmes. An estimate of extractable /9-glucan is obtained from the viscosity of an extract prepared by mashing barley at 50°C in an oc-aniylase-papain solution. The procedure is calibrated using solutions of known concentration of /9-glucan precipitated from barley extract by ethanol.

No abstract

Diastatic activity (Lintner value) and α‐amylase activity can be determined by the same colorimetric measurements of reducing sugars formed by the action of malt extract on a starch substrate. For the determination of α‐amylase activity, the β‐amylase is differentially inactivated by a phenyl mercuric salt before diastasis. Measurement of reducing sugars produced is based on their reaction with 3,5‐dinitro‐salicylic acid. Total amylase and α‐amylase activities may be recorded in the same units, or they may be converted to Lintner or SKB standard units with which they are closely correlated. There is considerable reduction in operating time and the methods are applicable in plant breeding projects or in quality control.

In 2 out of 5 years artificial inoculation of barley in field plots at Winnipeg, Manitoba, with speckled leaf blotch (Septoria passerinii Sacc.) caused statistically significant yield reductions of about 20 per cent. In 2 other years, inoculated plots yielded less than the check plots but the differences were not statistically significant. Tests on the malting quality of the grain from diseased and check plots of the last trial showed that the disease adversely affected the suitability of the barley for malting. Kernel shrinkage caused by the disease increased cleaning losses and reduced the amount of malt extract.

The inheritance of and interrelationships among six quality characteristics and yield were studied in 50 random lines of a wheat cross grown in Alberta. The heritabilities of all quality traits were higher than for yield with the exception of dough development time, which was characterized by a very high genotype ✕ year interaction variance. Seven of the 21 possible phenotypic correlations were significantly different from zero. Of these, the correlations between nitrogen content and yield, nitrogen content and starch damage, starch damage and yield, sedimentation value and dough development time, and between dough development time and tolerance index would be detrimental to a breeding program, while the correlations between thousand kernel weight and yield and between sedimentation value and tolerance index would be advantageous. The genotypic correlations agreed closely with the phenotypic correlations.