Transmission of HetRV6 ve HetPV13 Mycoviruses to Heterobasidion abietinum and Heterobasidion annosum isolates

Abstract

Heterobasidion annosum Fr. Bref. sensu lato is a highly destructive disease factor that causes root and root collar rot in the temperate zone of the Northern Hemisphere, especially in coniferous tree species. In the control of Heterobasidion species, the selection of tree species that are not host to the fungus, chemical substances and biological control agents are used. However, none of these control methods provide complete protection against the pathogen. In this context, it is important to search for sustainable alternative methods of combating the disease agent. Many fungal species, including Heterobasidion species, are known to host a large number of different mycoviruses. These mycoviruses are used as biocontrol agents to minimize the losses caused by pathogenic fungi and control the disease. In this study, it was aimed to investigate the possibilities of fighting against annosum root and butt rot by mycovirus transmission. In the experiments, two donor isolates infected with HetPV3-an1 and HetRV6-ab6 viruses and 5 H. annosum sensu str. and 20 H. abietinum isolates without virus were used. Isolates in both groups were tested in a dual culture in Petri dishes with 2% malt extract agar and incubated at 20 ° C for 3 months. At the end of the incubation period, the hyphae taken from the tip of the developing hyphae and the junction between the colonies were transferred to Malt-Orange Serum Agar medium. Potential dsRNA transfer to the recipient isolates occurred was determined using the RT-PCR method with specific primers. At the end of the trials, the dsRNA particle of 15% of the tested H. abietinum isolates and 20% of the H. annosum isolates were successfully transferred and the presence of single segment virus was confirmed by RT-PCR. Based on these results, even it is thought that the percentage of mycovirus transmission is low, and it can be used as biocontrol agent in future in vivo studies.

Keywords

• dsRNA
• Donor isolates
• Annosum root rot

HetRV6 ve HetPV13 mikovirüslerinin Heterobasidion abietinum ve Heterobasidion annosum izolatlarına aktarımı

Abstract

Heterobasidion annosum Fr. Bref. sensu lato, Kuzey Yarım kürenin ılıman kuşakta yer alan ülkelerinde, özellikle ibreli ağaç türlerinde kök ve kök boğazı çürüklüğüne neden olan oldukça tahripkâr bir hastalık etmenidir. Heterobasidion türlerinin mücadelesinde, fungusun konukçusu olmayan ağaç türlerinin seçimi, kimyasal maddeler ve biyolojik kontrol etmenleri kullanılmaktadır. Ancak, bu kontrol yöntemlerinin hiçbiri patojene karşı tam koruma sağlamamaktadır. Bu bağlamda, hastalık etmeni ile mücadele yöntemlerinin geliştirilmesinde sürdürülebilir alternatif metotların araştırılması, önem arz etmektedir. Heterobasidion türleri de dahil olmak üzere birçok fungal türün, çok sayıda farklı mikovirüs topluluğunu barındırdığı bilinmektedir. Bu mikovirüsler, patojen fungusların neden olduğu kayıpları en aza indirerek hastalığı kontrol altına alabilmek üzere biyokontrol ajanı olarak kullanılmaktadır. Bu çalışmada, mikovirüs aktarımı ile, annosum kök ve alt gövde çürüklüğüne karşı mücadele olanaklarının araştırılması amaçlanmıştır. Denemelerde HetPV3-an1 ve HetRV6-ab6 virüsü ile enfekte iki donör izolat ile virüs içermeyen 5 adet H. annosum sensu str., 20 adet H. abietinum izolatı kullanılmıştır. Her iki grupta yer alan izolatlar %2 malt extract agar bulunan Petri kaplarına karşılıklı olarak ekilmiş ve 20°C’de 3 ay süre ile inkübe edilmiştir. İnkübasyon süresi sonunda, gelişmekte olan hiflerin uç kısmından ve koloniler arasındaki birleşim noktasından alınan hifler, Malt- Orange Serum Agar ortamına aktarılmıştır. Alıcı izolatlara potansiyel dsRNA aktarımının gerçekleşip gerçekleşmediği, spesifik primerler ile RT-PCR metodu kullanılarak belirlenmiştir. Denemeler sonunda, test edilen H. abietinum izolatlarının % 15’ si, H. annosum izolatlarının ise % 20’si dsRNA partikülü başarılı bir şekilde aktarılmış ve RT-PCR ile tek segmentli virüs varlığı kesinleştirilmiştir. Bu sonuçlardan yola çıkılarak, mikrovirüs aktarımı yüzdesinin düşük de olsa başarılı olduğu ve gelecekte in vivo çalışmalarla biyokontrol ajanı olarak kullanılabileceği düşünülmektedir.

Keywords

• dsRNA
• Donör izolat
• Annosum kök çürüklüğü

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