Ahsanul Haque

Galea, Victor J.

Goulter, Kenneth C.

van Klinken, Rieks D,

University of Queensland eSpace

Botryosphaeriaceae fungi as a potential
mycoherbicide for prickly acacia
MrAhsanul Haque
The University of Queensland
ahsanul. haque@uqconnect. edu. au
Ahsanul Haque{r), Victor Galea(r), Ken Goultedr) , Rieks D van Klinken(2r
(r)School ofAgriculture and Food Sciences, The University of
Queensland, Gatton, Qld 4343, Australia('?)CSIRO Ecosystem Sciences, GPO Box 2583, Brisbane eld 4001,
Australia
Prickly acacia (Acacia nilotica ssp. ndlca) is one of the Weeds
of National Significance (WONS) in Australia. Recenfly,
dieback symptoms ranging from stem lesions, partial crown
death through to widespread death of plant populations were
observed in many locations across north Queensland. Fungi
were isolated from stem tissues of symptomatic plants andjdentified by sequencing of the ITS region. This revealed the
consistent presence of Botryosphaeria mamane from every
site. Several other species of Botryosphaeriaceae and varrous
mitosporic fungi were also recovered. All the isolates were
screened for pathogenicity under laboratory conditions using
a seedling bioassay. A sub-set of aggressive isolates across
the range of species found were used to challenge juvenile
plants by stem inoculation under glasshouse conditions to
determine the potential use of these fungi as mycoherbicides.
Based on preliminary glasshouse trials, three highly
pathogenic isolates identified as Botryosphaeria mamane,
Botryosphaeria sp. and Laslodlp lodia pseudotheobromae (all
Botryosphaeriaceae) were selected for further testing. Of these,
Lasiodiplodia pseudotheobromae (sourced from dieback-
affected parkinsonia) was shown to be highly pathogenic to
prickly acacia in preliminary trials. These three isolates were
then tested singly and in all combinations in both glasshouse
and field trials. Fungi were applied in field trials using a
gelatine capsule delivery system. In the glasshouse trial,
Lasiodiplodia pseudotheobromae alone and in combination with
Botryosphaeria mamane and a Botryosphaeria sp. developed
significant externally and internally visible stem lesions. Field
trials were first assessed six months after inoculation. Stem
lesions and stem bleeding (similar to that observed in the
glasshouse trial) were observed at one location. Symptoms
such as defoliation, stem and branch cankers and crown
distortion were not observed but observations are ongoing.
Findings from the glasshouse trial and preliminary field
observations suggest thal Lasiodi plodia pse udotheobromae
shows promrse as a mycoherbicide for prickly acacia.
SESSION 78 
- 
PLANT PATHOGEN INTERACTIONS
Profiles of Fusarium species and
mycotoxin on white corn varieties in the
Philippines
Dr Cecilia Pascual
Philippine Phytopathological Society
cbpascual22@yahoo.com
Cecilia Pascual, Eureka Teresa Ocampo, Ana Kristine Barcos
Crop Science Cluster-lnstitute of Plant Breeding, College ofAgricu[ure,
University of the Philippines Los Bafros, College, Laguna Philippines
4031
In the Philippines, the last five years has seen the rise in
atmospheric temperatures and consequent increase in
Fusarium ear rot incidence. Fusarium from corn oroduces
a carcinogenic class of mycotoxins called Fumonisins that
have been implicated in esophageal cancer in corn-eating
communities and also causes detrimental animal disorders.
To determine the Fusarium species and the isolates that
produce Fumonisins, Fusarium-infected corn ear samples
were collected from major corn growing areas of the country.
lsolatron into pure culture and identification were done following
the standard protocol. Of the two hundred ten (210) Fusarium
isolates collected, 184 were Fusarium vefticillioides based on
morphological and cultural characteristics. This was confirmed
by PCR using species-specific primers. The ability to produce
Fumonisins was also assessed using Fumonisin-specific primer
and by ELISA. A total of 175 Fusarium vefticillioides isolates
produced Fumonisins. lsolates that were positive to Fumonisins
but were not F. vefticillioides were tested for other Fusarium
species such as F. proliferatum and F. graminearum using
species-specific primers. However, only F. prolife ratum was
detected in 10 out of 15 Fumonisin-producing isolates. Further
investigation will be conducted to verify the identity of other 5
isolates. During the regional collection of Fusarium-infected
ears jn corn-eating communities in the province of Cebu, it was
observed that some localities were still planting the traditional
variety Tiniguib, a very low-yieiding and short cob white corn.
Fusarium ear rot was seldom observed in Tiniguib. Infected
Tiniguib showed very mild symptom of pinkish discoloration of
kernels and was negative to Fumonisin although microscopic
observation indicated that the isolates were Fusarium soecies
based on conidial morphology. Severe symptoms of whitish pink
to lavender fungal groMh were observed in IPB Var 6, a newly
introduced high-yielding white corn vatiety. Fusarium isolates
from IPB Var 6 were Fumonisin-producing F. vefticillioides.
Further evaluation with artiflcial inoculation of virulent E
vefticillioides isolate will be conducted in these two varieties to
confirm resistance.
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Botryosphaeriaceae fungi as a potential mycoherbicide for prickly acacia

http://espace.library.uq.edu.au/view/UQ:327559/a2013_haque_et_al_apps_conference.pdf

Botryosphaeriaceae fungi as a potential mycoherbicide for prickly acacia

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