Efeito da translocação 2NS na resistência da brusone da espiga de trigo no Sul de Minas

Abstract

Wheat blast, caused by the fungus Pyricularia oryzae pathotype Triticum (PoT), is one of the most concerning diseases for tropical wheat production. This disease can severely affect grain yield, as the edaphoclimatic conditions of the Cerrado are favorable to spike infection by the pathogen. Within integrated plant disease management, control through resistant cultivars is widely adopted and is considered the most economical, efficient, and sustainable strategy. Therefore, this study aimed to identify the effect of the 2NS translocation on resistance to wheat spike blast in Southern Minas Gerais across multiple environments, as well as its impact on yield components. The treatments consisted of eight wheat cultivars, selected for being the most widely grown in the study region. In total, six experiments were established and conducted at the experimental farms of UFLA, located in Ijaci and Lavras, from 2021 to 2025. At each site, plots measured 5 m² and were arranged in four replications. Wheat spike blast incidence was assessed at growth stage 83 of the Zadoks scale, along with grain yield (kg ha⁻¹) and thousand kernel weight (TKW; g). The data were subjected to individual and combined analyses of variance, mean comparisons, GGE biplot analysis, and correlation analysis. Significant differences (p ≤ 0.05) among cultivars were observed for all evaluated traits within individual environments, with selective accuracy ranging from 0.79 to 0.99. In the combined analysis, the sources of variation—cultivars, environments, and their interaction—were all significant (p ≤ 0.001). The cultivars with the lowest mean incidence were ORS1403 and TBIODuque. The highest-yielding cultivars were BRS404, ORSFeroz, TBIOAton, and TBIODuque, while BRS404 and ORSFeroz exhibited the highest thousand kernel weight. In the GGE biplot, the patterns followed the same trend as the means, highlighting TBIODuque as the cultivar with superior resistance and productivity. Significant negative correlations were observed between yield and incidence, between incidence and the presence of the translocation, and between TKW and the presence of the translocation. In conclusion, the cultivar TBIODuque showed high and stable resistance across multiple environments, associated with higher yields. The 2NS/2AS translocation reduced wheat blast incidence; however, it did not contribute to increases in yield or thousand kernel weight.