Response of carrot seed germination to heat treatment, the emergency measure to reduce the risk of ‘Candidatus Liberibacter solanacearum’ seed transmission

In Europe and the Mediterranean region, ‘Candidatus Liberibacter solanacearum’ (Lso) is associated with emerging diseases of Apiaceae crops, mainly carrot. Emergency measures for import carrot seed were set, requiring to be heat-treated at 50°C or tested as Lso-negative by PCR. The germination response heat treatment was assessed 24 cultivar hybrid lots. Ten parsley, five fennel, two celery lots also analysed. Of these 41 lots, 21 Lso-infected. Water significantly decreased germinability compared dry treatment, indicating that a cheaper less detrimental procedure. However, untreated controls in four carrot, ten parsley three fennel one For reduced lesser extent Lso-infected than Lso-free These data show can affect seeds varying degrees, depending on species variety, type sanitary status seeds.