Journal of Plant Pathology (2010), 92 (4, Supplement ... - Sipav.org

Journal of Plant Pathology (2010), 92 (4, Supplement), S4.71-S4.105 S4.81
primary inoculum for transmission mechanical means or by Bumble
bees. How PepMV infection initiates in new areas is now understood,
but tomato seed has been suspected as one of the key
components of worldwide epidemics. The objective of this study
was to investigate the role of PepMV transmission by Bumble
bees. Observations were carried out in different farms in Ragusa
province. The tomato genotypes were Genio and Shereen (severe
symptoms on the fruits), Piccadilly (mild symptoms) and Belize
(symptomless) In some farms 70 Bumble bees were used per
1,000 mq (thesis A), while in others 140 or more (thesis B). At
the beginning of the observations 10% of plants were infected.
By the end of March, 30% of plants were infected in the farms A,
while in B the infection rate was between 60 and 90%. The cultivation
procedures and transplant dates were practically identical
in all farms. On the basis of our observations we can affirm that a
high number of Bumble bees significantly contributed to the
spread of PepMV.
INHIBITORY EFFECT OF FURFURALS CONTAINED IN
THE STEAM-EXPLODED BIOMASS OF MISCANTHUS
SINENSIS AGAINST SOIL-BORNE PLANT PATHOGENS.
U. De Corato 1 , N. Sharma 2 , O. Maccioni 2 , F. Zimbardi 3 . 1 Agenzia
Nazionale per le Nuove Tecnologie, l’Energia e lo Sviluppo Economico
Sostenibile (ENEA), Unità Tecnica Efficienza Energetica,
Servizio Agricoltura, Centro di Consulenza Energetica Integrata di
Bari, Via Roberto Da Bari 119, 70122 Bari, Italy. 2 Laboratorio di
Biotecnologie dell’ENEA, Centro Ricerche Trisaia, S.S. 106 Jonica
Km. 419.500, 75026 Rotondella (MT), Italy. 3 Laboratorio di Biomasse
e Solare Termico dell’ENEA, Centro Ricerche Trisaia, S.S.
106 Jonica Km. 419.500, 75026 Rotondella (MT), Italy. E-mail:
ugo.decorato@enea.it
The Steam-Exploded Biomass (SEB) of Miscanthus sinensis, a
herbaceous perennial species growing up to 3-4 m in height, with
an annual yield of 20-25 tons/ha, is a good renewable energy resource.
SEB could also be useful in crop protection, as an alternative
to the use of compost in the greenhouse against soil-borne
plant pathogens. Detailed studies on disease suppressiveness of
SEB yielded positive results against three pathosystems. In this
work, we studied the inhibitory effect of furfurals contained in
the SEB against Phytophthora nicotianae, Pythium ultimum,
Fusarium oxysporum f. sp. lactucae, Fusarium oxysporum f. sp.
melonis and Rhizoctonia solani. Analysis of microbial growth inhibitors
was carried out by HPLC, and inhibition of furfurals was
tested in vitro. Furfural, 5–HMF, lignosulfonates, acetic and
formic acid were detected at a concentration of 2.93, 0.28, 4.12,
10.07, 1.88 g/l, respectively. P. ultimum, P. nicotianae and R.
solani were inhibited by the addition to PDA of 3.2 g/l furfural
and 0.48 g/l 5–HMF. However, both furfurals were not efficient
inhibitors of F. oxysporum f. sp. lactucae and melonis at the same
concentrations. An increase of furfural and 5–HMF concentration
in the growing medium correlated positively with inhibition
of P. ultimum, P. nicotianae and R. solani, but not with the growth
of F. oxysporum. Disease suppressiveness of SEB could be related
to its content of furfurals, organic acids and lignosulfonates produced
during processing of fresh biomass in a pilot plant of
Steam-Explosion.
THE INFLUENCE OF YEAST ORIGIN AND IDENTITY
ON MODES OF BIODEGRADATION OF PATULIN BY
BASIDIOMYCETOUS PINK YEASTS. F. De Curtis 1 , R.
Quici 1 , G. Ianiri 1 , L. Palmgren 2 , V. De Cicco 1 , R. Castoria 1 ,
S.A.I. Wright 1,2 . Dipartimento di Scienze Animali, Vegetali e del-
l’Ambiente, Università del Molise, Via F. De Sanctis, 86100 Campobasso,
Italy. 2 Department of Plant and Environmental Sciences,
University of Gothenburg, Göteborg, Sweden. E-mail: decurtis
@unimol.it
Pink yeasts belonging to the genera Sporobolomyces/Sporodiobolus,
Rhodosporidium/Rhodotorula, Cystofilobasidium/Cryptococcus
and Erythrobasidium are natural inhabitants of many agricultural
and wild plant species. Their natural role in the microbial
ecology of the phylloplane is not sufficiently understood.
When isolated and purified, many are able to suppress plant diseases
and some can biodegrade patulin. Pink yeasts were isolated
from the phyllosphere of agricultural and wild plants in various
climatic zones, islands, coastal, hilly and mountainous regions of
south-central Italy. Yeasts were purified and characterized by
morphological and molecular methods. Subsequently, they were
tested for the ability to degrade patulin, a mycotoxin produced
by Penicillium expansum, the causal agent of blue mould. The
highest degree of yeast biodiversity was recorded in the Tremiti
islands, because more species of plants were sampled and because
of the absence of intense agricultural activity. Most of the
170 pink yeasts isolated belonged to the genus Rhodosporidium.
More yeasts were isolated from apple and fig trees than from
olive in three comparable locations. Fig trees had a more diverse
epiphytic microflora than did apple and olive. Interestingly, apples
appear to host predominantly two different types of pink
yeasts, as shown by analysis of morphological traits, RFLP (restriction
fragment length polymorphism) and sequencing of the
ITS (internal transcribed spacer) regions. We have evidence suggesting
that members of specific phylogenetic groups are capable
of degrading patulin. No isolates from wild plants were able to
biodegrade patulin.
CHARACTERIZATION OF RESISTANCE TO QOI FUNGI-
CIDES IN BOTRYOTINIA FUCKELIANA (BOTRYTIS
CINEREA). R.M. De Miccolis Angelini, C. Rotolo, S. Pollastro,
A. Santomauro, M. Masiello, F. Faretra. Dipartimento di Protezione
delle Piante e Microbiologia Applicata, Università degli
Studi “Aldo Moro”, Via Amendola 165/A, 70126 Bari, Italy.
E-mail: faretra@agr.uniba.it
Botryotinia fuckeliana (Botrytis cinerea), the grey mould fungus,
is well known for its adaptability to adverse conditions that
frequently lead to acquired resistance to fungicides. QoIs include
fungicides effective against a broad spectrum of fungi. They act
as mitochondrial respiration inhibitors at the cytochrome bc 1 -
complex level and are considered at high risk of acquired resistance.
The response of B. fuckeliana field isolates, collected prevalently
from grapevine in Italy, France, Germany and Japan, to
several QoI fungicides was evaluated by colony-growth and conidial-germination
assays. Media were amended with various concentrations
of QoIs along with salicylhydroxamic acid, a specific
inhibitor of alternative oxidase. Tested fungicides showed different
effectiveness against B. fuckeliana. Positive cross resistance
between QoI fungicides belonging to different chemical groups
was observed. One-hundred-thirty-four isolates were characterized,
35 of which showed a high level of resistance (RF ≥ 200).
All isolates carried the G143A mutation in the mithocondrial cytochrome
b (cytb) gene, as shown by CAPS (Cleaved Amplified
Polymorphic Sequences) analysis with the AluI enzyme. Classical
genetic analysis confirmed that QoI-resistance is maternally inherited
by ascospore progeny of sexual crosses. The polymorphic
structure of the cytb gene of B. fuckeliana was investigated in 52
sensitive and 47 resistant isolates. A 1.197-bp intron (group I)
was detected, flanking downstream codon 143 of the gene exclu-