Why does the barley seed – amylase induction experiment no longer respond to GA?
Like you, this experiment/demo used to work a treat 30 years ago, but became more and more unreliable such that we dropped it. Obviously, sterility is important as almost any bacteria will produce amylase. We dipped the seed samples in diluted bleach, with a small piece of matchstick as a control to demonstrate that the bleach itself did not digest starch. The main problem is that the plant breeders have spent the last 30 years selecting short straw varieties which are resistant to lodging and can therefore respond to higher doses of N fertiliser with a heavier head without falling over. These varieties are short straw because they do not respond to GA in the normal way. They are non-responsive to GA in the seed’s response in amylase production as well as in the stem’s response in elongation growth. We were able to get a small sample of long-straw barley seed and this worked well for a few years, but the seed is not easy to get. Long straw wheat and barley are still grown in UK for tha
