A comprehensive study of spike fruiting efficiency in wheat

Spike fruiting efficiency (FE), defined as grains per unit of spike dry weight at anthesis (SDWa) is a promising trait for improving grain number (GN) in wheat (Triticum aestivum L.). It is often estimated at maturity as the grains per unit of chaff or FE at maturity (FEm). The fertile floret efficiency (FFE), defined as fertile florets per unit of SDWa, and grain set (GST), or the number of grains per floret, were studied to better understand FE determination for the first time. Two double haploid populations designed by crossing modern cultivars contrasting for FE [‘Baguette 19’ and ‘Baguette Premium 11’(high FE) × ‘BioINTA2002’ (low FE)] were sown in five environments. The FE and FEm showed an unstable correlation (low or high) among genotypes within environments (caused by variable SDWa–chaff associations), resulting in a worse correlation between GN and FEm than between GN and FE. Therefore, the use of FEm as a surrogate for FE to improve GN may yield lower gains than those expected if FE were used. The narrow-sense heritability of FFE was high but the variability in fertile florets per spike among genotypes within environments was correlated with FFE only in the environments with high SDWa. Despite the close 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 genotype × environment effects determine heavy spikes at anthesis, is an alternative to breeding for improved GN.Fil: Pretini, Nicole. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires; ArgentinaFil: Terrile, Ignacio Ismael. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria Pergamino; ArgentinaFil: Gazaba, Luciana N.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria Pergamino; ArgentinaFil: Donaire, Guillermo M.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Marcos Juárez; ArgentinaFil: Arisnabarreta Dupuy, Sebastián. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria Pergamino; ArgentinaFil: Vanzetti, Leonardo Sebastián. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Marcos Juárez; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: González, Fernanda Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires; Argentin

A modification of the test of Shapiro and Wilk for normality

The W statistic of Shapiro and Wilk provides the best omnibus test of normality, but its application is limited up to n= 50. This study modifies W, such that it can be extended for all sample sizes. The critical values of W, i.e. the modification of W, is given for n up to 5000. The empirical moments show that the null distribution of W is skewed to the left and is consistant for all sample sizes. Empirical powers of W are also comparable with those of W.