LMA screening is NOT conducted routinely under CAIGE, however some data on CAIGE materials has been provided by co-operators over the years. These data are presented below.
Late maturity α-amylase (LMA) in wheat is a quantitative genetic defect present at varying frequency in all Australian, and many overseas, breeding programs. Expression of LMA, both the incidence and extent, is difficult if not impossible to predict due to the complex G x E x maturity interaction. Where it occurs, developing grains synthesize high pI α-amylase during the middle stages of grain filling. The enzyme is retained through ripening and can cause a reduction in the falling number (FN) of harvested samples which then do not meet receival standards.
Outline of steps in LMA phenotyping
Information courtesy of
Associate Professor Daryl Mares & Dr Kolumbina Mrva
University of Adelaide
School Agric, Food & Wine
08 83037262 or daryl.mares@adelaide.edu.au
Grow plants in the glasshouse
Tag spikes at anthesis
LMA induction: At approximately 25 days after anthesis, subject plants or detached tillers to a cool temperature shock (controlled environment growth chamber 120C night/180C day) for 7 days
Return plants/tillers to a warm environment to complete ripening
LMA quantitation: Amount of α-amylase protein determined using a high pI-specific ELISA
Statistical design and analysis: Entries replicated in 2 blocks and within each block, pot positions are randomised. Subsequently, samples are assigned a random position on a series of 96 well microplates. The data is analysed by the national statistics program and entries are rated according to a probability that they have lower α-amylase than +LMA controls
Practical application of LMA data: LMA data is required to support applicaions by wheat breeding companies for classification of new varieties
