Grain Biodeterioration of Sorghum Converted Lines Inoculated with a Mixture of Fusarium thapsinum and Curvularia lunata

摘要

Background and Objective: Globally, grain mold is a major hurdle affecting sorghum productivity and quality. This disease is caused by complex fungal pathogens, among them Fusarium thapsinum and Curvularia lunata are the major fungi prevalent in many sorghum growing regions. This study examined the effect of inoculating a mixture of F. thapsinum and C. lunata on 60 sorghum converted lines with five adapted inbred lines as checks. Materials and Methods: Sorghum lines and checks were evaluated in field trials at the Texas AgriLife Research Station. Plants were inoculated with a mixture of F. thapsinum and C. lunata at 50% bloom. Results: The overall result showed that SC 725 (PI 534101), SC 218 (PI 534127), SC 691 (PI 534050), SC 91 (PI 534145) and Sureno exhibited grain mold severity of 2.3 or less. This level of grain mold infection was lower than the scores exhibited by the two resistant checks RTx 2911 (2.8) and SC 719-11E (2.5). Significant negative correlation (r = -0.385, p = 0.002) between grain mold and germination indicated the impact of these two fungi infection on germination rates. The significant negative correlation detected between germination and daily maximum temperature during the evaluation period shows planting of sorghum cultivars/hybrids that mature during periods of dry moderate weather will avoid problem of grain mold infection. Conclusion: The identified four converted lines for grain mold resistance in this study is recommended to use in breeding program to introgress grain mold resistance genes into other adapted sorghum inbred lines to increase the yield and seed quality traits.