Fruiting efficiency: an alternative trait to further raise wheat yield potential

SLAFER, GA; ELIA, M; ACUÑA M, GONZÁLEZ FG, SAVIN R, SLAFER GA; GARCIA G A; TERRILE IGNACIO; FERRANTE A; MIRALLES DJ; GONZALEZ FERNANDA G

Food and Energy Security

Wiley

Año: 2015

Further improvements in wheat yields are critical, for which increases in grainnumber would be required. In the recent past, higher grain number was achievedthrough increased growth of the juvenile spikes before anthesis, due to thereduction in stem growth. As current cultivars have already an optimum height,alternatives must be identifi ed for further increasing grain number. One of themis increasing fruiting effi ciency (grains set per unit of spike dry weight at anthesis).Fruiting effi ciency is the fi nal outcome of the fate of fl oret developmentand differences in this trait within modern cultivars would be related to highersurvival of fl oret primordia. Then there are two alternative physiological pathwaysto improve fruiting effi ciency by allowing a normal development of mostvulnerable fl oret primordia: an increased allocation of assimilates for the developingfl orets before anthesis, or reduced demand of the fl orets for maintainingtheir normal development. Both alternatives may be possible, and it might becritical to recognize which of them is the actual cause of differences in fruitingeffi ciency. When considering this trait in breeding we must be aware of potentialtrade- offs and therefore it must be avoided that increases in fruiting effi ciencybe constitutively related to decreases in either spike dry weight at anthesis orgrain weight. In this review we described fruiting effi ciency and its physiologicalbases, analyzing genetic variation and considering potential drawbacks that mustbe taken into account to avoid increases in fruiting effi ciency being compensatedby other traits.