Tomato irregular-ripening symptom development and ripening of silverleaf whitefly-infested dwarf cherry tomatoes.

摘要

Silverleaf whitefly (SLW) (Bemisia argentifolii) feeding was associated with development of tomato irregular ripening (TIR) symptoms in plants grown in Florida, USA. Dwarf cherry tomato cultivars Micro-Tom, Florida Basket, Florida Lanai and FloridaPetite were infected with adult SLW to observe oviposition preference, plant tolerance and TIR symptom development. There was no oviposition preference among the cultivars in either of the trials. TIR fruit symptoms were expressed as longitudinal red streaks with yellow, green, pink or red external blotches, and white internal tissue. External TIR symptoms at the pink stage of ripening ranged from 32% (Micro-Tom) to 82% (Florida Basket) in one experiment (Expt. 1), and 44% (Micro-Tom) to 93% (Florida Petite) in another (Expt. 2). During ripening, external TIR symptoms disappeared from 18% (Florida Lanai) to 37% (Micro-Tom) of fruits in Expt. 1, and from 16% (Micro-Tom) to 39% (Florida Basket) in Expt. 2. SLW-infected plants exhibited 82% (Florida Lanai) to 99% (Florida Basket), and 76% (Micro-Tom) to 90% (Florida Petite) of fruits with internal white tissue regardless of external symptoms in Expts. 1 and 2, respectively. Tomatoes with severe TIR symptoms rarely ripened to full red. Postharvest characteristics of ripening SLW-infected and control fruits were evaluated. Generally, infected fruits were lighter in colour than the controls. Control fruits developed normal red colour, and infected fruits developed a blotchy, streaky orange-red colour. Infected fruits were firmer than controls. Ethylene production was higher in infected fruits. Although the total soluble solids did not differ significantly between the treatments, infected fruits were more acidic than controls. Each cultivar was susceptibleto oviposition by SLW and induction of TIR symptoms. However, TIR symptom expression differed among the cultivars. Despite higher ethylene levels, the ripening process in the infected fruits appeared to be slower, and it is suggested that it may have been inhibited by factors induced by SLW.