.7514 lO' 6381 lO' (') CONSUMO LIMITE
2 MISES ANTES Y DESP DI RIAL MI.CHA INTDUPon'LI.
lagenarium
Yonghong Ge{ XE "Ge, Y." } and David Guest
Faculty of Agriculture, Food and Natural Resources, The University of Sydney, Sydney, 2006, NSW AUSTRALIA
INTRODUCTION
Melon is an economically important horticultural crop that is
susceptible to anthracnose caused by Colletotrichum
lagenarium. Two types of infections are caused by
Colletotrichum species: intracellular hemibiotrophic invasion or
subcuticular intramural necrotrophic invasion (1). However, the
infection process of melon anthracnose caused by C. lagenarium
remains unknown. This study of the compatible interaction
between C. lagenarium and melon leaves investigated the
infection process and monitored defence responses of the
melon plant.
MATERIALS AND METHODS
Preparation of infected tissues. Seeds of rockmelon cv. Galaxy
and Ultra sweet Miami (Terranova seeds Pty Limited, NSW,
Australia) were grown in 10 cm plastic pots filled with UC potting
mix in the glasshouse at 24oC, with illumination for 16 h. Plants
were watered daily and fertilised with Aquasol® weekly. Three
week old seedlings were inoculated on the abaxial surface of the
first leaf with a suspension of 106 conidia mL‐1 of C. lagenarium.
Inoculated plants were maintained at 25oC, 100% relative
humidity for 24 h, then returned to the glasshouse.
Light microscopy. Leaf samples were collected at 6, 12, 24, 48,
72, 96 hrs after inoculation. Decolourised sections were
immersed in lactophenol for 1min and then stained with 0.025%
aniline blue for 30 min. After staining, the tissues were rinsed
(2!2min) in lactophenol and mounted in fresh lactophenol on
glass slides for microscopy(2). Callose was visualized under UV
after staining with aniline blue (3).
RESULTS AND DISCUSSION
Figure 1. Infection structures of C. lagenarium in the first leaves of
rockmelon. (A) Ungerminated conidia on the leaf surface with stomata 6 hai. (B) Conidia with germ tubes 12 hai. (C) Melanised appressoria 24 hai. (D) Appressorium with penetration peg 48 hai. (E) Formation of infection vesicle and primary hyphae 72 hai. (F) Formation of secondary hyphae 96 hai.
c=conidia;s=stomata; gt=germ tube; a=appressorium; pp=penetration peg; ph=primary hyphae;sh=secondary hyphae; iv=infection vesicle;hai=hour after inoculation.Bars=20μm.
Conidia attached and germinated on the leaf surface 6 hai (Fig.
1A), and differentiated a germ tube at one tip 12 hai (Fig. 1B).
Melanised appressoria were first observed 24 hai, sometimes
formed directly from one tip of the conidium (Fig. 1C), or from
the tip of the germ tube. Penetration pegswere observed 48 hai
(Fig. 1D). By 72hai, epidermal cells of melon leaves had been
penetrated and contained intracellular fungal structures
comprising swollen, saccate infection vesicles with elongated
neck regions (Fig. 1E). Infection vesicles enlarged and formed
primary hyphae (Fig. 1E), and at this stage of host‐pathogen
interaction, infected melon leaves were symptomless. Beyond
72 hai, secondary hyphae developed from the primary hyphae
and invaded surrounding tissues (Fig. 2F), and the infected
melon leaves developed visible anthracnose symptoms. The
results also indicated that the resistant and susceptible cultivars
use the same infection process.
Callose deposition around the infection sites was noted 48 hai in
susceptible and resistant cultivars (Fig. 2, Fig. 3). Callose
deposition was brighter and more intense in the resistant
cultivar.
Figure 2. (A) Light and (B) UV micrographs showing the accumulation of
callose 48 hai of the first leaves of susceptible melon with C. lagenarium. (C) Light and (D) UV micrographs showing the accumulation of callose 48
hai of resistant melon.
a=appressorium; Ca=callose
These results indicate that the infection process of C. lagenarium
was intracellular hemibiotrophic invasion.
ACKNOWLEDGEMENTS
This research was supported by the Australian Centre for
International Agricultural Research (ACIAR). We thank Suneetha
Medis for technical assistance.
REFERENCES
1. Bailey JA, O’Connell RJet al. (1992) Infection strategies of Colletotrichum species. In Colletotrichum: Biology, Pathology and
Control (JA Bailey, and MJ Jeger, Eds), CAB International
2. Latunde‐Dada AO, Bailey JAet al.(1997) Infection process of Colletotrichumdestructivum O’Gara from lucerne (Medicagosativa
L.). European Journal of Plant Pathology 103, 35‐41.
3. Borden S, Higgins VJ (2002) Hydrogen peroxide plays a critical role in the defence response of tomato to Cladosporium fulvum. Physiological and Molecular Plant Pathology 61, 227‐236.
Posters
70 Disease‐managementwood strategies production for fromthe rural exotic sector plantations that help
deliver sustainable
C. BeadleA, A. RimbawantoB, A. FrancisC, M. Glen{ XE "Glen, M." }A, D. PageC, C.L. MohammedA,C
A
CSIRO Sustainable Ecosystems, Private Bag 12, Hobart, Tasmania 7001, Australia
B
Centre for Biotechnology and Tree Improvement, Yogyakarta, Indonesia
C
Tasmanian Institute of Agricultural Science and School of Agricultural Science, University of Tasmania, PB 54, Hobart, TAS 7001,
Australia
INTRODUCTION
A training workshop and post‐workshop field trip was held in
May 2009 in Indonesia to advance knowledge and understanding
in disease management. It was opened by the Minister for
Forestry and attended by a wide range of participants from the
forest, oil palm and rubber industries, universities, and research
and government agencies. The workshop was supported by
international experts from South Africa, the United Kingdom and
Australia.
Case studies were used at the workshop to provide training and
exposure for participants in concepts of forest pathology,
biosecurity and forest health surveillance and their application
towards developing strategies for disease management. These
case studies focused on disease issues and threats of immediate
relevance to tree crops in Indonesia, for example, fungal rot in
hardwood plantations, rubber and oil palm, rust galling in Paraserianthes falcata, and the significance of a guava rust
incursion. An exercise was carried out in the field to train in the
basic concepts of ground based forest health surveillance. The
field trip in Sumatra examined demonstration sites and
experiments in acacia and eucalypt areas most severely affected
by root rot, and included hands‐on experience in disease
assessment and novel ways to examine disease risk.
OUTPUTS OF TRAINING EXERCISE
Position paper. The position paper focuses on using all available
information about root and basal stem rot in plantation‐based
industries to assist in capturing both the current status of forest
disease management capacity in Indonesia and what type of
capacity will be required to combat some very serious diseases
of plantation crops. It first considers the background that has led
to root rot and basal stem rot becoming diseases that have a
significant economic effect on plantation‐based industries. A
summary of the current size of the plantation estates in the oil
palm, pulpwood and rubber industries is then provided. These
sections give us an idea of the possible returns from investing in
building capacity.
The paper then collates information that has been collected
from professional staff working in both the private and public
sector in roles that are connected to disease management for oil
palm, forestry (primarily pulpwood) species and rubber, and
supports this information with that from published literature. A
separate section considers the concept of ecosystem
management—this research focus lies primarily in the public
sector. Next there is a dissertation on biological control that
examines the potential characteristics and development of
control agents and the challenges that must be overcome to
make them work. These three sections assist in highlighting the
types of research and operational disease management capacity
required.
The current capacity to deliver professional services in disease
management is then examined. The paper concludes with a
consideration of the part of Indonesia’s higher education system
that delivers training in Plant Protection and Plant Pathology and
policy directions that are relevant to both this education and the
application of disease management.
Proceedings and DVD Disease Management Strategies in
Plantations. The Proceedings will summarise the information
from the workshop from the various sessions (Introduction to
Disease Management; Morphological and Molecular
Identification Tools; Forest Health Surveillance; Biosecurity;
Chemical, Genetic and Biological Control; Silvicultural and Risk
Management; Integrated and Ecosystem Management; Policy
Development).
The DVD which contains all the talks from the Workshop is
available on request and the Proceedings will be available in
September.
Field guide. A field guide to the identification of basidiomycete
root rot diseases in tree crops will be published at the end of
2009. This will include crown and root symptoms associated with
the various stages of root rot disease and a description of the
sporocarps associated with the various fungal pathogens capable
of causing root rot disease.
SUMMARY
As in Australia there is little specific University training in forest
pathology or disease management. Plant pathology education is
comparatively well resourced in Indonesia, especially in Bogor,
and the industries can draw from this pool of graduates. Barriers
to building expertise in forest disease management lie in the fact
that young people do not wish to live in remoter regions and
there are often organisational barriers to the sharing of
expertise and a collaborative approach to solving problems, even
within the same industry.
The Government of Indonesia has no formal approach to disease
management in its forest policy. However the Minister has
acknowledged the problem of disease, especially root‐rot
disease (which is probably the most serious pest problem faced
by the hardwood plantation industry) and is actively encouraging
a cooperative approach to disease management. Substantial
funding is potentially available to promote this collaboration and
this supports the case for more open communication as was
achieved by the workshop and field trip. Root rot disease has
been a surprising catalyst for opening pathways of
communication.
ACKNOWLEDGEMENTS
We thank the AUSAID Public Sector Linkage Programme for
funding this activity. We also thank the many numerous
Indonesian colleagues who participated in this activity.