Spike growth regulating rate of death and survival of floret primordia seem key processes determining grain number in wheat

GONZÁLEZ FG, SLAFER GA, MIRALLES DJ

St Petersburgh

Conferencia; 8 International wheat conference; 2010

Improvements of wheat yield potential will be essential to meet the future food demand. As yield is related to the number of fertile florets and grains, understanding their generation may be instrumental to improve yield. It has been suggested that floret survival is associated to spike growth based on (i) a positive association observed between the number of fertile florets or grains and the spike dry weight at anthesis, and (ii) that floret death occurs when the spikes grow at maximum rate. However, when this idea was recently tested it has been strongly questioned. Analysing six independent experiments (chamber/field) with diverse treatments (photoperiod/shading) and cultivar types (winter/spring, semi-dwarf /standard-height, photoperiod sensitive/insensitive), we show that floret death and survival are constitutively linked to pre-anthesis spike growth. Therefore, it would be worthwhile focusing on traits associated with spike growth when breeding to further rise wheat yield.