Assessing the Vulnerability of Sorghum Converted Lines to Anthracnose and Downy Mildew Infection

A total of 59 converted sorghum lines and 6 checks were evaluated for resistance to two foliar fungal diseases, anthracnose and downy mildew (SDM) in 2008 and 2009 growing seasons at the Texas A&M AgriLife Research Farm, College Station, Texas. In 2008, 23 lines exhibited resistance (35%), 29 susceptible (45%) and 13 variable responses (20%) while 15 lines showed resistance (28%), 31 susceptible (57%), and 8 variable responses to anthracnose in 2009. Nine lines SC748, PI534101, PI534073, PI533950, PI534155, PI533802, PI533776, PI533911 and PI533759 exhibited anthracnose resistance response in both years. Significantly a wide range of 8 to 89% SDM incidence was observed in the study. None of the lines recorded SDM resistance reaction in both years. However, 15 lines PI534119, PI533983, PI597970, PI534160, PI570726, PI534161, PI534112, PI576374, PI533753, SC748, PI533991, PI569998, PI534050, PI534155 and PI533898 recorded moderate resistance to SDM incidence and recommended for use in further breeding programs. There was a positive significant correlation (P = 0.0392) between anthracnose and SDM, indicating that the lines showing higher SDM incidence favors higher anthracnose infection. Significant correlation between precipitation and SDM was also noted. SC748 and PI534155 exhibited resistance to anthracnose and downy mildew diseases and hold promise for utilization in breeding programs as potential checks.