Vol. 61 No. 3 (2022): including the "60th MPU Anniversary Special Section"

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

Research Centre for Plant Protection and Certification, Council for Agricultural Research and Economics (CREA-DC) Via C.G. Bertero, 22, 00156 Rome
Research Centre for Plant Protection and Certification, Council for Agricultural Research and Economics (CREA-DC) Via C.G. Bertero, 22, 00156 Rome
Research Centre for Plant Protection and Certification, Council for Agricultural Research and Economics (CREA-DC) Via C.G. Bertero, 22, 00156 Rome
Sabrina BERTIN
Research Centre for Plant Protection and Certification, Council for Agricultural Research and Economics (CREA-DC) Via C.G. Bertero, 22, 00156 Rome
Vincenza ILARDI
Research Centre for Plant Protection and Certification, Council for Agricultural Research and Economics (CREA-DC) Via C.G. Bertero, 22, 00156 Rome

Published 2023-01-13


  • Apiaceae,
  • Daucus carota,
  • 50°C,
  • seed import-export,
  • FAO-IPPC emergency action

How to Cite

L. TIZZANI, A. GENTILI, A. TAGLIENTI, S. BERTIN, and V. ILARDI, “Response of carrot seed germination to heat treatment, the emergency measure to reduce the risk of ‘Candidatus Liberibacter solanacearum’ seed transmission”, Phytopathol. Mediterr., vol. 61, no. 3, pp. 513–522, Jan. 2023.

Funding data


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


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