In vitro evaluation of temperature influence on native Sclerotinia sclerotiorum carpogenic germination of Northwest Argentina

Abstract

Production of bean (Phaseolus vulgaris L.), is an important agricultural activity in Northwestern Argentina (NWA). Currently, fungus Sclerotinia sclerotiorum originates one of the most serious health problems. Sclerotia, which is able to carpogenic or miceliogenic germinate and infect to plants. Temperature prior sclerotia germination is among other environmental factors that can change and influence pathogenicity of the disease. This study aimed at studying the influence of temperature on the carpogenic germination of a native isolate of Sclerotinia sclerotiorum. An isolate of LA11 strain identified as S. sclerotiorum from infected bean plants originated at Catamarca province was used in this study. Sclerotia of the pathogen were subjected to temperatures of 4 and 25 (± 2) °C for a period of four weeks and then incubated on wet sand at 20 (± 2) °C to promote carpogenic germination. The results showed that a mean of germinated sclerotia equal to 86% and a germination rate of 3.7 apothecia/ sclerotia/ week were observed for sclerotia treated at the lowest temperatures. In the case of sclerotia treated at the highest temperatures, a mean of 43% and rate of 2.2 apothecia/ sclerotia/ week were found. LA11 strain behaves as a pathogen that requires low temperatures to produce more carpogenic germination. This knowledge will allow design strategies for timely and efficient management to reduce pathogen disease levels.