Genotype × environment interaction on the yield of spring oilseed rape (Brassica napus) under rainfed conditions in Argentine Pampas

PUHL, L. E.; MIRALLES, D. J.; LÓPEZ, C. G.; IRIARTE, L. B.; RONDANINI, D. P.

JOURNAL OF AGRICULTURAL SCIENCE

CAMBRIDGE UNIV PRESS

Año: 2019 vol. 157 p. 235 - 244

0021-8596

Oilseed rape seed yield has increased in the last 40 years in most countries, but this yield gainhas not been accompanied by greater yield stability. The current study aimed to quantify thegenotype by environment (G × E) interaction on oilseed rape yield, identify genotypes withbroad adaptability and the main environmental drivers related to seed yield. A weightedtwo-stage mixed-model analysis was applied to official multi-environment trials of ninespring genotypes (G), in three locations (L) during 6 years (Y) on central and southernArgentine Pampas under rainfed conditions. Best linear unbiased prediction of seed yield ranged from 0.37 to 3.73 kg/ha. Fixed effect L × Y was highly significant and G variability wasestimated as 130 kg/ha of standard deviation. Contrasting genotypes were identified byShukla?s stability index and two of those showed the best yield performance in the wettestyear. Factor analysis explained 0.75 of total variation and discriminated genotypes withbroad and specific adaptability, as well as combined environments according to the similarities in seed yield of the evaluated genotypes. Environmental loadings of Factor 2 were linearlyassociated with cumulative rainfall in the post-flowering period (up to 230 mm). It is concluded that (i) a significant G × L × Y interaction underlies the high variability of seedyield, (ii) two genotypes (G6 and G7) with high yield stability were identified, and (iii)G × E effects are associated with post-flowering rainfall