Effect of three cycles of recurrent selection for yield in four Spanish landraces of maize

Abstract Landraces of maize ( Zea mays L.) have a variability not found in the elite hybrids due to bottleneck during selection. There is renewed interest using that variability, incorporating alleles for specific traits, or widening general germplasm. In Europe, there also an direct use local landraces by farmer’s associations seeking agriculture preserves crop diversity. Pre-breeding programs are aimed reduce yield gap among and improved materials. Misión Biológica de Galicia we carried out three cycles S 1 recurrent selection program on four from Northwestern Spain with objective obtaining populations might be cultivated farmers could used as sources superior inbred lines. One hundred plants were selfed each landrace families evaluated 10 × simple lattice. The 20 highest grain yields randomly intercrossed form selected population landrace. After selection, its locations two years. All had consistent gain first cycle However, response later differed populations: one continuous increase 21% per while reduced last cycles. Our results highlight need include secondary traits avoid unintentional indirect effects. We conclude that, pre-breeding programs, it worthy large effective numbers prevent inbreeding depression, particularly when landraces. Another conclusion does seem efficient European germplasm Corn Belt varieties. Finally, valuable new requires sustained, long-term effort.