Factors affecting symptom production by latent Botrytis cinerea in Primula×polyantha

Abstract

Latent infection by Botrytis cinerea was frequently detected in young Primula × polyantha (horticultural hybrid polyanthus) plants. Genetically marked isolates were used to demonstrate that conidial inocula applied to young plants generally did not result in disease appearing on the leaves until plants flowered, regardless of when plants were inoculated. The severity of disease was proportional to the length of each day spent at 100% relative humidity during the latent period, regardless of time or form of inoculum. Plants with a prior B. cinerea infection were more susceptible to further infection and also showed symptoms of B. cinerea infection more quickly. Bacteria found to be associated with B. cinerea increased the likelihood of B. cinerea symptoms being seen on the plant, but did not directly assist infection.

Persistent, symptomless, systemic, and seed-borne infection of lettuce by Botrytis cinerea

“…These experiments were not designed to test under what conditions Botrytis can change from an endophytic phase to an aggressive phase of growth. Stress in growth, post-harvest storage, or damage by other pathogens or pests, may trigger more aggressive growth and cause symptoms (Barnes and Shaw, 2002). The isolates responsible for the systemic infection reported here seem to be similar to those responsible for aggressive infections, because isolates from non-symptomatic plants caused normal spreading brown lesions when drop-inoculated on detached leaf pieces.…”

Botrytis species: relentless necrotrophic thugs or endophytes gone rogue?

“…Botrytis ‐specific monoclonal antibody labelling of whole mounts of lettuce root, stem and leaf sections detected internal hyphal spread within roots and above‐ground parts (Sowley et al ., ). These and other data suggest the following life cycle: young seedlings or seeds are infected by spores; the resulting mycelium grows actively for weeks or months in an association which is at least partly inside the host; when the host flowers, the lifestyle changes to an aggressive attack (Barnes and Shaw, ); abundant spores are produced which infect seed heads and/or seedling plants, and the cycle is repeated.…”

Development of real-time PCR (TaqMan®) assays for the detection and quantification of Botrytis cinerea in planta

“…Consequently, an apparently healthy plant can deteriorate suddenly due to the development of latent or quiescent infection into visible disease. The factors that trigger this transition are still poorly understood, though there is evidence in certain hosts that they involve physiological changes associated with the loss of plant defences [1,4,31]. Plant age, mineral nutrition, wounding, wetness duration, temperature at harvest and inappropriate storage may also play a part in the emergence of infections [10,22,28,29,33].…”