POTENTIAL OF POPCORN S4 LINES FOR RESISTANCE TO SOUTHERN CORN LEAF BLIGHT

Abstract

Popcorn crop is distinguished by its higher profitability when compared to the common maize. Nevertheless, it has a scarce amount of information and a genetic material resistant to foliar diseases that affect the crop. In view of the mentioned conditions, this work aimed at evaluating popcorn S4 lines, coming from different genealogies, for resistance to B. maydis. The experiment was conducted at a greenhouse in augmented block designs, with four blocks, and 78 lines from 13 genealogies were evaluated. The L-55, L-70, L-77, L-88, P-01, and P-08 lines were considered as controls and repeated in all blocks. The incidence of B. maydis in the plant was evaluated at 7 days, and the severity in the leaf, at 7 and 14 days after inoculation. The data of lines were subjected to analysis of variance; and the means were discriminated by the t-student test, considering as resistant the lines whose means did not differ from zero. With the purpose of evaluating the merits of the populations originated from the lines, the S4 lines were grouped, following each genealogy, using boxplot graphs. Regarding the leaf severity, there was a significant effect for both evaluations, proving there was variability among the different lines. In the first evaluation, 83.3 percent of the lines reported means statistically equal to zero; after 14 days, the percentage decreased to 37.2 percent. In the second evaluation of severity, lines resistant to B. maydis obtained from SE_013, SAM, PR_023, PARA_172, PA_170_R, PA_091, CHZM_13_134, BOZM_260, ARZM_07_049 could be identified.