Field Resistance of Different Sugarcane Varieties to Sugarcane Thrips (Fulmekiola serratus) in China

Field resistance against sugarcane thrips (Fulmekiola serratus) in 21 sugarcane varieties was tested following inoculation with a natural population. The results revealed differences in pest incidence levels in different varieties and between different leaf positions in the same variety. The tested varieties were subsequently categorized into four levels of resistance (Grades 1–4). The variety GT31 and LC05-136 showed the highest resistance (Grade 1), with a pest index of less than 0.35, while 12 varieties including FN91-21 and FN39 had a pest index of 0.35–0.45 (Grade 2). Five varieties including YT60 and YZ03-194 had a pest index of 0.45–0.55 (Grade 3), while FN38 and DZ03-83 had the lowest resistance (Grade 4), with a pest index of greater than 0.65. Correlation analysis further revealed that the number of thrips present on a single plant was related to the level of resistance; however, the correlation was relatively weak. These findings provide a preliminary evaluation of thrips resistance screening in sugarcane, laying the foundation for analysis of thrips-resistant genes, breeding of thrips-resistant varieties and resistance evaluation in new sugarcane germplasms.