DISTINGUISHING BETWEEN LATE MATURITY ALPHA-AMYLASE AND PRE-HARVEST SPROUTING

摘要

The correct identification of wheat varieties prone to late maturity alpha-amylase (LMA) is extremely important to breeding companies in Australia. Currently, wheat varieties are not classified for release unless they pass two tests where LMA is artificially induced. However laboratory induced LMA does not always correlate with the expression of LMA in the field. As a result some good quality wheat varieties, that would not give low falling number in their intended environment, are never released togrowers. It is difficult to prove that a variety does not exhibit LMA in the field because low wheat falling number values (WFN) can be due to LMA, Pre-Harvest Sprouting (PHS) or both. The method for screening for LMA proposed by S.Uthayakumaranet al In:Cereals 2008. Proc. 58th Aust. Cereal Chem Pp. 156-159, where the germ and outer layers are stripped from the grain with a pearling machine, seems to offer a quick solution to this problem. The results of their research, albeit on a very limited numberof samples, clearly distinguished between PHS, LMA and sound grain. In this paper the possibility of using the pearling method, as a routine test for samples from a breeding program is explored. Data from a number of varieties at many sites are presented. As an adjunct to this research, a linear regression to assist with judging the correct time of pearling for individual samples was investigated.