LIBRO-CONGRESO-CITRUS

into two groups: one dried in the shade for four hours (77%) and the other dried with forced air for 72 hours (54
%). Seeds of lemon ‘Cravo’ were dried in the shade at room temperature for four hours (71%). Three fungicide
pretreatments were evaluated: 1) fungicide dip (imazalil- 2mL/L) for two minutes; 2) fungicide spray (captan-
0.5g/L); 3) fungicide dip (imazalil- 1mL/L) for two minutes followed by fungicide spray (captan- 0.5g/L) after
drying. Treated seeds were divided in lots of 200g, packed in common plastic bags or micro perforated Xtend
polyethylene bags, and further stored in cold chamber at 5°C and 70% HR. Seed viability in each treatment
was evaluated by periodic sowing for 10 months and the percentage of germinated seeds was calculated.
Seed weight loss during storage was also evaluated. The packaging Xtend showed promising results for the
storage of seeds of ‘Swingle’ citrumelo and lemon ‘Cravo’, compared with the package currently used in citrus
nurseries. Seed longevity was improved, without reducing seed germination, and the appearance of mold
fungi was prevented.
S15P31
Morphological and molecular diversity of Phytophthora nicotianae strains isolated from citrus
plantations in Cuba
Llauger R., Coto O., Peña M., Zamora V., and Collazo C.
Instituto de Investigaciones en Fruticultura Tropical, Cuba. direccion@iift.cu
A collection of Phytophthora spp. isolates was built with strains collected from citrus plants showing symptoms
of Gummosis. Sampled areas belong to two of the most important Cuban citrus enterprises (Jagüey Grande
and Ceiba del Agua). Eight P. nicotianae strains isolated from citrus plants were identified considering
sporangia length and width and its ratio. A P. nicotianae strain isolated from mango and a well characterized
strain isolated from citrus plantation in Brazil were used for comparative purpose. Only two strains were
identical in the cluster analysis done based on the sporangia traits measured and a morphological diversity
was observed between Cuban P. nicotianae isolates obtained from citrus. Sporangia were variable in shape,
mostly ovoid-ellipsoid, obpyriform, spherical and distorted. Pathogenicity assays showed the capacity of the
strains to affect Mexican lime fruits and rootstocks plants under in vitro conditions and re-isolation of the
pathogens were done from infected fruits. Molecular identification using primers pairs Pn5B/Pn6 specific
to P. nicotianae confirmed the previous morphological identification. The sequences of amplified products
obtained using ITS5/ITS4 primers pairs with DNA template of four of the strains were compared in the NCBI
Genbank- using BLAST and confirmed the identification as P. nicotianae isolates and the diversity of the
Cuban strains. Those sequences were included in the NCBI Genbank with the accession numbers: GUO73388,
GUO73387, GUO73392 and GUO73389.
XII INTERNATIONAL CITRUS CONGRESS 2012 - 271
S15