DEVELOPMENT OF F-4 LINES OF AMARANTH (Amaranthus spp.) FROM INTERVARIETAL CROSSES

In the amaranth crop (Amarantus spp.) it is important to develop new varieties with the ideotype required by producers, suitable for mechanized planting and harvesting, with medium plant height to resist lodging, uniformity in plant height, inflorescence length, grain maturation, resistance to diseases and shattering, high yield potential and and good grain quality. In Mexico, the amaranth breeding is only based on mass selection, obtaining materials through the phenotype, and genetic diversity of the crop has not been fully exploited; therefore, the objective of this study was to obtain advanced F-4 lines through single crosses to advance to a higher phase and have promising lines and suitable varieties for amaranth producers. With the mini-plant cultivation technique, direct crosses were made, from which 6404 seeds in F-2 were obtained, and those were used to constitute uniform groups. During the Spring-Summer (SS)-2017 agricultural cycle, 18 segregating F-3 populations were selected through the modified bulk method, and in SS-2018 the same method was continued where eight segregating F-4 populations were obtained with plants from 1.30 to 1.65 m in height, suitable for mechanized harvesting, compact panicles, with greater synchrony in flowering, which resulted in a higher grain weight per panicle (80 %). Through the improvement of amaranth by genetic recombination, the generation of modern varieties suitable for mechanized harvesting, with profitability and sustainability of the crop are feasible.