Transposon tagging in the causal agent of olive anthracnose Colletotrichum sp

First Report of Phytophthora palmivora on Grevillea spp. in Italy.

The genus Grevillea (family Proteaceae) comprises over 300 species and is a popular and widely cultivated group of Australian plants. In the last 3 years, numerous potted grevilleas with symptoms of decline associated with a rot of feeder roots were found in ornamental nurseries in Sicily. Aboveground symptoms were reduced growth, yellowing of foliage, wilt, dieback, and death of the entire plant. The disease was observed on many commercial cultivars and was especially severe on G. alpina (mountain grevillea), G. juniperina (juniper-leaf grevillea), G. lavandulacea (lavender grevillea), and G. rosmarinifolia (rosemary grevillea) as well as the hybrid cultivars Clearview David (G. lavandula…

Resistance of Phytophthora capsici to metalaxyl in plastic-house capsicum crops in southern Italy

In Calabria (southern Italy), control of crown and root rot of capsicum caused by Phytophthora capsici has relied primarily on soil drenches of metalaxyl. However, severe outbreaks occur every year in glasshouse crops, in which the practice of using plastic mulch and furrow irrigation favours the disease. Single-hypha isolates of P. capsici collected in Calabria in 1992/1998 were tested in vitro for their level of sensitivity to metalaxyl. Isolates of other species of Phytophthora were used as reference. Fungicide sensitivity was determined by plating mycelial plugs onto potato dextrose agar amended with metalaxyl, at final concentrations ranging from 0.1 to 1000μg mL−1 a.s. Inhibition of r…

First report of Phytophthora palmivora as a pathogen of olive in Italy

Olive (Olea europea L.) is an economically important crop in Italy and is planted on about 1 million ha. The Apulia, Calabria, and Sicily regions of Southern Italy account for about 70% of the production. Many new plantations have been established during the last 10 years. In summer 1999, 1- to 2-year-old olive trees (cv. Carolea) with decline symptoms were observed in new plantations in Catanzaro Province (Calabria). The symptoms associated with the root rot were leaf chlorosis, defoliation, wilting, twig dieback, and eventual plant collapse. In some cases, more than 40% of the trees were affected. A Phytophthora sp. was isolated consistently from rotted rootlets of diseased trees using a…

Characterization of Colletotrichum species causing anthracnose of ornamentals and horticultural crops in Italy

Phytophthora species causing crown and root rot of tomato in southern Italy

Phytophthora capsici, Phytophthora cryptogea and Phytophthora nicotianae were isolated from tomato plants with symptoms of crown and root rot in plastic-house crops in Sicilia and Calabria (southern Italy). The species were identified primarily on the basis of morphological and cultural characteristics. The identification was confirmed using molecular methods, polyacrylamide gel electrophoresis (PAGE) of mycelial proteins and polymorphism of DNA sequences amplified by polymerase chain reaction using random primers (RAPD-PCR). P. capsici caused significant losses in tomato crops that had succeeded capsicum crops. P. cryptogea was found to be the most frequent species causing basal stem rot o…

Collar and root rot of olive trees caused by Phytophthora megasperma in Sicily

Olive (Olea europea L.) is grown on about 154,000 ha in Sicily (southern Italy). In the summer of 1999, a few 3-year-old olive trees with decline symptoms were observed in a recently planted commercial orchard in the Enna province (Sicily). The trees were propagated on wild olive (O. europea L. var. sylvestris Brot.) rootstock. Aerial symptoms, consisting of leaf chlorosis, wilting, defoliation, and twig dieback followed in most cases by plant death, were associated with root rot and basal stem cankers. A Phytophthora sp. was consistently isolated from rotted rootlets and trunk cankers using the BNPRAH (benomyl, nystatin, pentachloronitrobenzene, rifampicin, ampicillin, and hymexazol) sele…