Diagnosis and detection of fungi occurring on grapevines in Australia 8th International Congress of Plant Pathology, Christchurch, New Zealand, 2003

Grapevine diseases National Wine and Grape Industry Centre (NWGIC) Industry Symposium, Wagga-Wagga,

NSW Australia 2003

Diagnosis of trunk diseases Hunter Valley Vineyard Seminar Trunk disease Management “Understanding the Big Picture”,

NSW, Australia 2003

Role of ! conidia of Phomopsis viticola in cane and leaf blight of grapevines (Vitis vinifera L.)

Australasian Plant Pathology Society 13th Biennial Conference, Cairns, Queensland, Australia, 2001

diagnostic and research work presented at national and international conferences

Grapevine diseases in Australia

Dr Vera Sergeeva

• Grapevines grow all over the country of Australia

• A wide range of fungi occur on grapevines during different stages of their growth

• Fungi can infect different parts of grapevines such as berries, wood and green tissue

• Some of fungi are primary invaders while others are secondary invaders

• Fungi can exist together on grapevines and competition between some these fungi are not obvious

• The trunk diseases are difficult to diagnose in the vineyard because similar symptoms are caused by different fungi

• Diseases have the potential to affect yield of grapes

• They also have the capacity to affect the quality of wine

Grapevine diseases are caused by range of pathogens. They have serious impacts on both fruit yield and quality of wine.

Several fungi, some of pathogenic importance, were observed on grapevines from different viticultural regions of Australia. Twenty-three species of fungi belonging to nineteen genera were recorded during a five-year period from 1997 to 2002:

Botrytis cinerea, Greeneria uvicola, Colletotrichum acutatum,C. gloeosporiodes, Botrytosphaeriacea species, Eutypa lata, Cytospora sp., Pestalotiopsis uvicola, P.menezisiana., Seimatosporium sp., Phomopsis viticola, Coniella diplodiella, Broomella acuta, Aschochyta sp., Volutella sp. Rhizoctonia sp., Rhizopus sp., Fusarium sp, Pythium sp. , Aspergillus niger, Penicillium sp., were recorded.

Phomopsis

Botrytis

Greeneria

similar symptoms bleaching are caused by different fungi

Botryosphaeria

Colletotrichum

Seimatosporium

Pestalotiopsis

Ripe rot Colletotrichum sp

Grey rot Botrytis cinerea

Fruit rot diseases

Downy mildew Plasmopara viticola

Powdery mildew Uncinula necator

Bitter rot Greeneria uvicola

White rot Coniella diplodiella Macrophoma rot

Botryosphaeria sp.

Phomopsis bunch rot Phomopsisi viticola

Pestalotiopsis rot Pestalotiopsis uvicola Photo credit Peter Magarey

Grey rot/Botrytis rot caused by Botrytis cinerea

Bunch rot caused by Botrytis cinerea is a major disease of grapes in many grape growing areas that causes millions of dollars of crop loss as well as a reduction in vine quality. It is the most difficult fungal disease to control, particularly when wet weather occurs around harvest.

Mummified berries infected with B. cinerea

germinating sclerotia

sclerotium

Flower infection by Botrytis cinerea

Botrytis (basic disease cycle)

Botrytis on grapes

Aborted, infected flowers trapped within bunch

Indicates the importance of pre-bunch closure spray

Mycelial of Botrytis cinerea growth in vitro fungicide resistance bioassay

Ripe rot caused by Colletotrichum spp.

Disease favoured by warm, wet weather. Survives as dormant mycelium in mummified berries

immature berries

mature berries

• The fungus survives on dormant wood

• The salmon-coloured spores produced in spring causes disease in new season

Colletotrichum acutatum and C.gloeosporioides isolated from dormant canes and buds are reported for the first time

spore mass

Bud infection

dormant cane infected with Colletotrichum

bleached spur

scarring

infected berries

Phomopsis bunch rot caused by Phomopsis viticola (rarely observed)

Mummified fruits carry fungal infection

Phomopsis viticola alpha and beta conidia

Oozing pycnidium on dormant canes

Germination of ! conidia

Spore mass

Phomopsis can remain dormant Ininfected canes, spurs and dead wood for a number of years

Phomopsis on green shoot

infection on upper internodes

Phomopsis leaf symptoms

brown spots with yellow halo

Pestalotiopsis fruit rot caused by Pestalotiopsis uvicola

Flower infection

Berry infection

bleached spur

redish colour on internode

Oozing pycnidium on dormant canes after incubation

Pestalotiopsis uvicola

spore mass

spores

Pestalotiopsis on young vine

inhibition in budburst

Cross section of trunk infection by Pestalotiopsis uvicola through soil–root transmission

Pestalotiopsis uvicola infect canes, woods, green shoots, buds,

berries, flowers, leaves

Pestalotiopsis on young shoots at the base of trunk

Pestalotiopsis menezesiana

Spore mass

Seimatosporium hysterioides

acervulus

recorded infected canes caused by: Seimatosporium hysterioides Pestalotiopsis menezesiana Sporocadus rhododendriand Truncatella angustata

red colour

spores

Bitter rot caused by Greeneria uvicola

Infected berry

spores

Spore mass

Bitter rot (Greeneria uvicola) • Fungus overwinters on stem lesions and mummified berries • Infection starts at flowering • Spreads from stem-end to whole of berry • Light-colored berries become brownish and often show concentric rings of acervuli • Damages fruit especially if rainy weather persists into the harvest season • Grape berries have a bitter taste

acervuli

Dormant canes infected with Greeneria uvicola

Bud infection

cracking of epidermis Phomopsis viticola

Spore mass

showing symptoms of dead-arm, dieback, bud infection - reported for the first time

Spore mass Greeneria uvicola

sp.

Cross section of trunk infected with Greeneria uvicola

Botryosphaeria cross section of cordon (arm)

Botryosphaeriaceae species recorded in vineyards NSW, SA, WA including: Diplodia seriata, Diplodia mutila, Neofusicoccum parvum, Neofusicoccum australe, Botryosphaeria dothidea, Botryosphaeria stevency, Lasiodiplodia theobromae, Dothiorella viticola and Dothiorella iberica

Botryosphaeria associated disease: - Black dead arm - Botryosphaeria canker and dieback - Excoriose - Grapevine decline syndrome - Macrophoma rot - Diploidia cane dieback and bunch rot

Spore mass on dormant cane

Spore mass

Pycnidia of Botryosphaeria sp. produce spores in spring which are splashed onto green tissue

Macrophoma rot caused by Botryosphaeria sp.

Infected berries can shrivel and dry out

Conidia-bearing structures (pycnidia)

Cane infected with Botryosphaeria obtusa

Pycnidia under bark

Cross section of trunk infection by B. stevensii through soil–root transmission

Botryosphaeriaceae species are recognized as important pathogens symptoms vary depending on the species of fungi infecting aerial parts or through soil-root transmission

Cross section of trunk infected with several fungi, including Phaeomoniella chlamidospora and Fomitiporia

Esca disease complex involving several fungi, including Phaeomoniella chlamidospora (the fungus responsible for Petri disease) and Fomitiporia (a soft rotting fungus). Esca is rarely observed.

Eutypa dieback, caused by fungus Eutypa lata, is a major trunk disease of grapevines in NSW and SA. Grapevines symptoms of Eutypa dieback, dead spurs, cankers, or discoloured vascular tissue.

Wood symptoms caused by fungi individually & in combination

Infection of grapevine by wood infecting fungi can cause death of the plant

dead 2 years old spur and uneven budburst

Trunk diseases are usually diagnosed by isolations from discoloured tissue in the infected wood. Trunk disease pathogens may cause shoot, leaf or fruit symptoms but generally do not directly infect those parts of the vine. Cross section of trunk showed after isolation that different microflora was associated with each necrosis fungi genera such as: Phaeomoniella, Phaeoacremonium, Eutypa, Fomotipora Botryosphaeria, Pestalotiopsis, Phomopsis, Stereum, Greeneria

Young vine infected with Rhizoctonia and Fusarium

bark removed to show infection

Unknown

Open fruiting body (apothecium)

• Occurs on canes with other pathogens such as Phomopsis • Survives on dormant canes • Wet weather favours

Closed fruiting body

Thank you