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

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1 diagnostic and research work presented at national and international conferences 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

2 Grapevine diseases in Australia Dr Vera Sergeeva

3 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

4 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.

5 Phomopsis Pestalotiopsis Botrytis Botryosphaeria similar symptoms bleaching are caused by different fungi Seimatosporium Greeneria Colletotrichum

6 Fruit rot diseases Grey rot Botrytis cinerea White rot Coniella diplodiella Ripe rot Colletotrichum sp Macrophoma rot Botryosphaeria sp. Bitter rot Greeneria uvicola Downy mildew Plasmopara viticola Pestalotiopsis rot Pestalotiopsis uvicola Phomopsis bunch rot Phomopsisi viticola Photo credit Peter Magarey Powdery mildew Uncinula necator

7 Grey rot/botrytis rot caused by Botrytis cinerea germinating sclerotia sclerotium Mummified berries infected with B. 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.

8 Flower infection by Botrytis cinerea

9 Botrytis (basic disease cycle)

10 Botrytis on grapes Aborted, infected flowers trapped within bunch Indicates the importance of pre-bunch closure spray

11 Mycelial of Botrytis cinerea growth in vitro fungicide resistance bioassay

12 Ripe rot caused by Colletotrichum spp. mature berries immature berries Disease favoured by warm, wet weather. Survives as dormant mycelium in mummified berries

13 Colletotrichum acutatum and C.gloeosporioides isolated from dormant canes and buds are reported for the first time dormant cane infected with Colletotrichum Bud infection spore mass The fungus survives on dormant wood The salmon-coloured spores produced in spring causes disease in new season

14 Phomopsis bunch rot caused by Phomopsis viticola (rarely observed) scarring bleached spur infected berries Mummified fruits carry fungal infection

15 Phomopsis viticola alpha and beta conidia Spore mass Germination of! conidia Oozing pycnidium on dormant canes

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

17 Phomopsis on green shoot Phomopsis leaf symptoms infection on upper internodes brown spots with yellow halo

18 Pestalotiopsis fruit rot caused by Pestalotiopsis uvicola Berry infection bleached spur redish colour on internode Flower infection

19 Pestalotiopsis uvicola Oozing pycnidium on dormant canes after incubation spores spore mass

20 Pestalotiopsis on young vine inhibition in budburst

21 Pestalotiopsis on young shoots at the base of trunk Cross section of trunk infection by Pestalotiopsis uvicola through soil root transmission Pestalotiopsis uvicola infect canes, woods, green shoots, buds, berries, flowers, leaves

22 Pestalotiopsis menezesiana Spore mass

23 Seimatosporium hysterioides red colour acervulus spores recorded infected canes caused by: Seimatosporium hysterioides Pestalotiopsis menezesiana Sporocadus rhododendriand Truncatella angustata

24 Bitter rot caused by Greeneria uvicola Infected berry spores Spore mass

25 acervuli 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

26 Dormant canes infected with Greeneria uvicola showing symptoms of dead-arm, dieback, bud infection - reported for the first time Spore mass Spore mass Greeneria uvicola Bud infection cracking of epidermis Phomopsis viticola

27 Cross section of trunk infected with Greeneria uvicola sp.

28 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 Botryosphaeria cross section of cordon (arm)

29 Pycnidia of Botryosphaeria sp. produce spores in spring which are splashed onto green tissue Spore mass Spore mass on dormant cane Macrophoma rot caused by Botryosphaeria sp. Infected berries can shrivel and dry out Conidia-bearing structures (pycnidia)

30 Cane infected with Botryosphaeria obtusa Pycnidia under bark

31 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 infection by B. stevensii through soil root transmission

32 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.

33 Wood symptoms caused by fungi individually & in combination

34 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

35 bark removed to show infection Young vine infected with Rhizoctonia and Fusarium

36 Open fruiting body (apothecium) Closed fruiting body Unknown Occurs on canes with other pathogens such as Phomopsis Survives on dormant canes Wet weather favours

37 Thank you