Effect of sugarcane yellow leaf virus in the second clonal stage of the Canal Point Cultivar Development Program

Sugarcane yellow leaf virus (SCYLV) is an economically significant pathogen that can cause yield losses of 11% to 50% in susceptible clones. Clones (1534) in the second clonal stage (Stage 2) of the Canal Point Cultivar Development Program (CPCDP), three reference cultivars, CP78-1628, CP96-1252, and CP00-1101, and three disease-spreader cultivars, CP88-1762, CPCL02-6848, and CP01-2390, were screened to determine SCYLV infection using tissue-blot immunoassay. One hundred seventy-three clones (11%) were infected with the SCYLV, 29 had 100% SCYLV infection, 19 had 80%, 30 had 60%, 38 had 40%, 57 had 20% of SCYLV infection, and 1361 clones had no SCYLV (0%) infection. The 1534 test clones were derived from 400 crosses that utilized 127 female and 86 male parents in various combinations; 70% of these crosses, 46% of the males, and 54% of the females were related to SCYLV-free clones. The reference and disease-spreader cultivar CPCL02-6848 had 48% infection, followed by CP88-1762 with 38% infection, CP96-1252 with 13% infection, CP01-2390 with 6% infection, CP00-1101 with 5% infection, and CP78-1628 with 3%. The results show that SCYLV can infect many susceptible clones within 3 years of exposure from seed germination to Stage 2. However, the effect of SCYLV infection on yield was not significant in this study. Therefore, the yield losses from SCYLV should be limited by planting virus-free seed cane and good agronomic practices in Florida.