Fabio D'Anna

Genetic variation and evolutionary analysis of Pepino mosaic virus in Sicily: insights into the dispersion and epidemiology

Pepino mosaic virus (PepMV) is a highly infectious potexvirus that causes a severe disease in tomato (Solanum lycopersicum) crops worldwide. In Sicily, the first outbreak was detected in a single greenhouse in 2005 and it was promptly eradicated. However, in 2008, a large number of greenhouses were simultaneously affected, and it was impossible to eradicate or control the virus. This study addressed the dispersion and the genetic diversity of PepMV isolates obtained from the outbreak in Sicily, in comparison with worldwide PepMV isolates, to gain insight into the factors determining the evolution and epidemiology of the virus. A total of 1800 samples from plants with and without symptoms were collected in the Sicilian provinces of Agrigento, Caltanissetta, Palermo, Ragusa, Siracusa and Trapani. Three isolates collected at different times were biologically characterized. The incidence of the virus increased rapidly from 13% in 2011 to 63% in 2013, and phylogenetic analysis showed that all Sicilian isolates of PepMV belonged to the CH2 strain, one of the six strains previously described. Nucleotide diversity of the Sicilian isolates was low, thus suggesting rapid spread and genetic stability.

Soil Solarization as an Alternative to Methyl Bromide Fumigation for Annual Strawberry Production in a Mediterranean Area

ABSTRACT This study compares the effects of soil solarization and methyl bromide fumigation on the growth and yield of strawberry plants (Fragaria xananassa Duch.) cultivated under plastic tunnel conditions. The study was conducted in a Mediterranean coastal area, in four consecutive annual production cycles in a field with no history of methyl bromide fumigation and 2-year history of strawberry production. In all 4 years, solarization was conducted for 7- to 9-week intervals from late June to early September. Cultivar Tudla frigo-plants were planted through mulch in the first week of September of each year. Average daily soil temperatures in solarized plots measured at 15 cm depth were 6.0, 8.1, 7.8, and 8.4 °C higher than the control, during Summer 2001, 2002, 2003 and 2004, respectively. Solarization produced 781, 610, 630, and 525 hours above 37 °C at 15 cm depth during the first, second, third, and fourth year, respectively. In the first year, solarization significantly increased both early and total marketable yields by 15% compared with the fumigated plots, whereas in the successive years, solarization and fumigation were equally effective in increasing yields when compared to untreated plots. No significant differences in average fruit weight were observed between solarized and fumigated plots in individual years. The study demonstrated that the Mediterranean coastal areas have appropriate environmental conditions to apply soil solarization in strawberry planting as a viable substitute to methyl bromide fumigation.