A Comprehensive Study of Spike Fruiting Efficiency in Wheat

PRETINI, NICOLE; TERRILE, IGNACIO I.; GAZABA, LUCIANA N.; DONAIRE, GUILLERMO M.; ARISNABARRETA, SEBASTIÁN; VANZETTI, LEONARDO S.; GONZÁLEZ, FERNANDA G.

CROP SCIENCE

CROP SCIENCE SOC AMER

Año: 2020

0011-183X

The spike fruiting efficiency (FE, grains per unit spike dry weight at anthesis) is a promising trait to improve grain number in wheat. It is often estimated at maturity (FEm) as the grains per unit of no-grain spike dry weight (CHAFF). The fertile floret efficiency (FFE, fertile florets per unit spike dry weight at anthesis) and grain set (n grains floret-1, GST) were studied to better understand FE determination for the first time. Two double haploid populations (P1 and P2) designed by crossing modern contrasting cultivars for FE (Baguette and Baguette Premium 11 - high FE x BioINTA2002 - low FE) were sown in five environments. The FE and FEm showed an unstable correlation (low or high) among genotypes within environments (due to variable SDWa ? CHAFF association), resulting in a worse correlation between GN and FEm than between GN and FE. Then, use FEm as a surrogate to FE for improving GN may yield lower gains than those expected if FE were used. The H2 of FFE was high, but the variability in fertile florets per spike (FF) among genotypes within environments was correlated with FFE only in the environments with high SDWa. Despite the closely association between FE and FFE, the former was not totally set at anthesis as GST greatly affected FE and GN. Selecting for higher FFE and GST, where GxE determines heavy spikes at anthesis, is an alternative to breed for improved grain number.