Agronomy

Abstract

Hop (Humulus lupulus L.), valued by the brewing industry for its aromatic hop cones, is an important economic crop for Slovenia and in 2020 was cultivated on 1489 hectares of agricultural land and produced 2639 tons of hop cones (Travnikar et al. 2020). Every year, the yield and production of hops are severely challenged by the emergence of pathogenic organisms, which include fungi, bacteria, phytoplasmas, viruses and viroids. Slovenian hop plantations are at risk from three different viroids: hop latent viroid (HLVd), hop stunt viroid (HSVd), and citrus bark cracking viroid (CBCVd). The recently discovered CBCVd causes significant economic losses for the hop producers as it manifests in the most severe symptoms leading to plant death within 3 to 5 years. (Jakse et al. 2015). The objective of the postdoctoral research project is to elucidate the mechanism of the immune response of resistant hop cultivar(s) to the infection with CBCVd viroid. Understanding how the plant immune system functions during viroid infection and knowing the molecules involved in the immunity process are critical for developing new strategies to combat viroid infections and may accelerate the breeding of resistant hop cultivars. Preliminary data showed that the cultivar Styrian Wolf cannot be infected with CBCVd using any of the already established inoculation methods. In this project, a novel approach of in-vitro micrografting for viroid inoculation of the resistant hop cultivar will be developed to generate infected plant material that will be subjected to comparative transcriptomic analysis of CBCVd-infected and mock inoculated resistant and susceptible hop cultivars. More precisely, RNA-Seq with Ion Torrent: Proton System will be used to identify differentially expressed genes in different plant tissues and the expression pattern of the selected genes will be validated by RT-qPCR. The knowledge of CBCVd infection and the understanding of hop immune response gained in the proposed post-doctoral project will facilitate the further development and breading of CBCVd resistant hop cultivars.

Researchers

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The phases of the project and their realization

WP1, in progress: Inoculation of hops with CBCVd and screened for resistance and tolerance to the viroid.

WP2, in progress: Development of hops micro-grafting technique in in-vitro conditions.

WP3: Transcriptomic analysis to study viroid tolerance in hops.Citations for bibliographic recordslink na sicris