Tomato (Lycopersicon esculentum Mill.) accession PI 270248 (‘Sugar’) had high levels of resistance to bacterial spot [incited by Xanthomonas campestris pv. vesicatoria (Doidge) Dye] on fruit, but foliage was susceptible. Hawaii 7998 (H7998) was highly resistant to foliar infection, but was intermediate in resistance to fruit infection. Fruit spot on hybrids between ‘Sugar’ and H7998 was usually intermediate to the parents. Occasionally, disease incidence of hybrids was not statistically different from one or both parents, but tended to resemble ‘Sugar’ more closely than H7998. There were no significant differences between reciprocal hybrids, indicating a lack of cytoplasmic inheritance. Under low disease incidence, hybrids between ‘Sugar’ and ‘Walter’ (susceptible to bacterial spot on fruit and foliage) had fruit spot incidence similar to ‘Sugar’ and significantly less than ‘Walter’. Thus, there was a high level of dominance for resistance to bacterial spot on fruit.
Associate Professor of Vegetable Crops.
Assistant in Plant Pathology.
Associate Professor of Plant Pathology.
Received for publication 22 Aug. 1988. Florida Agricultural Experiment Station Journal Series no. 9658. This research was supported in part by the USDA under CSRS Special Grant no. 86-CRSR-2-2844 managed by the Caribbean Basin Advisory Group. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact.