Pietersen Gerhard, Smith Marie F
Research Scientist, ARC-Plant Protection Research Institute, Private Bag X134, Pretoria, 0001 South Africa.
Biometrician, ARC-Biometry Unit, Private Bag X519, Silverton, 0127 South Africa.
Plant Dis. 2002 May;86(5):528-534. doi: 10.1094/PDIS.2002.86.5.528.
A new disease of tomatoes (Lycopersicon esculentum) in South Africa has caused severe yield losses. The causative virus, Tomato curly stunt virus (ToCSV) is distantly related to Tomato yellow leaf curl virus (TYLCV). Thirty-two tomato accessions resistant to TYLCV and 8 local cultivars were assessed for their responses to ToCSV infection. Natural infection in a field trial and a screen-house trial with controlled ToCSV-inoculation were conducted. Symptoms were rated using a severity index (SI). Yield parameters were determined in the screenhouse trial to support SI evaluations. Average SI's obtained demonstrate that TYLCV-tolerant tomato accessions, with a few exceptions, have milder symptoms of ToCSV infection than TYLCV-susceptible, sensitive accessions. None of the accessions were immune, with some virus detected in all plants. Yield losses due to ToCSV infection of TYLCV-tolerant tomato accessions were not significant (P > 0.10) with some exceptions. However, TYLCV-sensitive accessions and 8 local cultivars had significant (P < 0.10) yield losses of 49 to 100%. TYLCV-tolerant cultivars may be useful for control of ToCSV, but require evaluation prior to release or use in breeding programs in South Africa.
南非番茄（Lycopersicon esculentum）的一种新病害已导致严重的产量损失。致病病毒番茄卷叶矮化病毒（ToCSV）与番茄黄化曲叶病毒（TYLCV）亲缘关系较远。对32份抗TYLCV的番茄种质和8个当地品种进行了ToCSV感染反应评估。开展了田间试验中的自然感染以及ToCSV接种受控的温室试验。使用严重程度指数（SI）对症状进行评级。在温室试验中测定产量参数以支持SI评估。获得的平均SI表明，除少数例外，耐TYLCV的番茄种质感染ToCSV的症状比感TYLCV的种质轻。所有种质均无免疫，所有植株均检测到一些病毒。耐TYLCV的番茄种质因ToCSV感染导致的产量损失除少数例外不显著（P>0.10）。然而，感TYLCV的种质和8个当地品种产量损失显著（P<0.10），达49%至100%。耐TYLCV的品种可能有助于防治ToCSV，但在南非发布或用于育种计划之前需要进行评估。
