Objectives:
O2.3.1: Determine changes in meristem/spikelet hormone (ABA, ACC, cytokinins, auxin) composition in wheat at key pre-anthesis stages of plant development (floret initiation, terminal spikelet initiation, anther lobe formation, meiosis, floret degeneration) and relate these changes to reproductive development (spike fertility index and grain filling)
O2.3.2: Determine changes in meristem/spikelet and leaf hormone (ABA, ACC, cytokinins, auxin) composition in wheat in response to controlled soil water deficits, nutrient treatments and changes in the photoenvironment, applied at key pre-anthesis stages of plant development (see above)
O2.3.3: Experiments in O2.1.2 will allow definition of G x E interactions in hormone balance that regulate spike fertility index and grain filling
O2.3.4: Determine the extent to which these changes are dependent on plant water relations, and/or leaf carbohydrate supply to the developing spike.
O2.3.5: Screen a wide variety of germplasm (from the germplasm described above) under controlled soil water deficits for hormonal traits associated with less conservative spike fertility.