Evaluation of tomato accessions for tospovirus and geminivirus resistance

Thirteen lines and three commercial tomato cultivars were screened for tospovirus and geminivirus resistance under field conditions, in Campinas, São Paulo State, Brazil. The germplasm comprised advanced IAC lines plus cultivars Stevens, Franco and IPA-5. The same experiment was carried out in two planting seasons. In the first (December 2001 to February 2002), only Tomato chlorotic spot virus (TCSV) occurred in the field. In the second (July to September 2002), Tomato yellow vein streak virus (TYVSV) was identified in the experimental area, and the evaluation was carried out through counting of infected plants and by symptom intensity scoring by notes. There were no treatment differences by using the first criterion, but the score evaluation was effective in detecting differences among genotypes; line IAC-S3-16 showed an outstanding performance. Considering the two trials, the susceptibility of 'IPA-5' to both pathogens was confirmed; in addition, resistance of 'Franco' to TCSV and TYVSV was observed. Lines IAC-S3-54, IAC-S3-318, IAC-S4-39 and IAC-SVS-1 could be distinguished for the low infection by TCSV. So, these lines can be considered as promising genetic material to obtain cultivars with resistance to both viruses and good agronomic traits.

Lycopersicon esculentum; Tomato chlorotic spot virus (TCSV); Tomato yellow vein streak virus (TYVSV); plant disease resistance