TY - JOUR

T1 - Botrytis cinerea kills groundsel (Senecio vulgaris) infected by rust (Puccinia lagenophorae)

AU - HALLETT, S G

AU - Paul, Nigel

AU - AYRES, P G

PY - 1990/1

Y1 - 1990/1

N2 - Inoculation of healthy groundsel (Senecio vulgaris L.) with Botrytis cinerea Pers at 1.24 × 106conidia ml −1 caused 10% mortality, and only 40%, mortality when plants were abiotically wounded before inoculation. However, all plants previously infected by rust (Puccinia lagenophorae Cooke) died after inoculation with B. cinerea. Mortality was most rapid it plants were inoculated with B. cinerea as rust colonies first erupted through the host's epidermis. A reduction in the concentration of conidial inoculum increased time to death, and concentrations below 015 × 103 conidia ml−1 failed to cause 100 % mortality within the 32 d of the experiment. Death of plants was associated with the growth of B. cinerea into stem bases; a reduction in the density of rust lesions on leaves had no effect on the time from inoculation to the appearance of foliar symptoms, but increased time-to-kill. There was little variation m virulence between isolates of B. cinerea made from different groundsel or ragwort (Senecio jacobaea L.) populations. Similar interactions between biotrophic fungi and opportunistic pathogens have occasionally been noted previously; their importance in natural vegetation processes and possible relevance to the biocontrol of weeds is discussed.

AB - Inoculation of healthy groundsel (Senecio vulgaris L.) with Botrytis cinerea Pers at 1.24 × 106conidia ml −1 caused 10% mortality, and only 40%, mortality when plants were abiotically wounded before inoculation. However, all plants previously infected by rust (Puccinia lagenophorae Cooke) died after inoculation with B. cinerea. Mortality was most rapid it plants were inoculated with B. cinerea as rust colonies first erupted through the host's epidermis. A reduction in the concentration of conidial inoculum increased time to death, and concentrations below 015 × 103 conidia ml−1 failed to cause 100 % mortality within the 32 d of the experiment. Death of plants was associated with the growth of B. cinerea into stem bases; a reduction in the density of rust lesions on leaves had no effect on the time from inoculation to the appearance of foliar symptoms, but increased time-to-kill. There was little variation m virulence between isolates of B. cinerea made from different groundsel or ragwort (Senecio jacobaea L.) populations. Similar interactions between biotrophic fungi and opportunistic pathogens have occasionally been noted previously; their importance in natural vegetation processes and possible relevance to the biocontrol of weeds is discussed.

KW - Groundsel (Senecio wilgaris)

KW - rust (Puccinia lagenophorae)

KW - Botrytis cinerea

KW - synergistic interaction

KW - host mortality

U2 - 10.1111/j.1469-8137.1990.tb00380.x

DO - 10.1111/j.1469-8137.1990.tb00380.x

M3 - Journal article

VL - 114

SP - 105

EP - 109

JO - New Phytologist

JF - New Phytologist

SN - 0028-646X

IS - 1

ER -