Evaluation of Rubus genetic resources on their resistance to cane disease

Abstract

Raspberry cane disease, caused by a complex of fungi, is amongst the most devastating problems for raspberry production. Using resistant or highly tolerant genotypes is a promising strategy. However, until now, cultivars with good field resistance for German fruit growers as well as the primary causal pathogens of cane disease present in the eastern part of Germany, Saxony state are still unknown. The primary objective of this study was to identify the primary disease causing organisms and resistant Rubus germplasm for future breeding efforts. From 2012 to 2014, we evaluated the degree of susceptibility to cane diseases on 213 raspberry cultivars at two different locations using a rating scale. We also identified the main fungi growing on infected canes. Our results suggest that Fusarium avenaceum is the main fungus causing cane disease in Saxony. The Rubus hybrid cultivars 'Tayberry' (2n = 6x = 42), 'Buckingham Tayberry' (2n = 6x = 42) and 'Dorman Red' (2n = 2x = 14) displayed the highest levels of field resistance at both locations. Moreover, we established an in vitro assay for resistance evaluation which correlates significantly with field data and is particularly suitable for quick assessment of resistance against F. avenaceum in breeding material. Future breeding programs, aiming at cultivars with enhanced resistance towards cane diseases can use the presented data for parental selection and may employ our in vitro F. avenaceum inoculation method for parental testing and progeny selection.

Paraconiothyrium fuckelii, Diaporthe eres and Neocosmospora parceramosa causing cane blight of red raspberry in Northern Italy

“…Moreover, D. eres and N. parceramosa were found in association with cane blight disease and produced symptoms on artificially inoculated raspberry plants. The occurrence of different fungal species demonstrated the presence of a complex of fungi involved in the development of raspberry cane diseases as described by Girichev et al (2018). Thus, considering the difficulty to distinguish different pathogens from symptoms or based on morphological traits, it becomes necessary the use of molecular tools to provide a correct identification (Girichev et al 2018).…”

“…Little information is known about the infectivity of ascospores, whilst conidia could be dispersed by splashing rains from early spring to late autumn and could enter through cane wounds causing infection and considerable losses in raspberry production (Dolan et al 2018). Girichev et al (2018) reported raspberry cane disease as caused by a complex of different phytopathogenic fungi. Moreover, several fungal species can survive as saprophytes on canes with a role in disease development (Girichev et al 2018).…”

“…Girichev et al (2018) reported raspberry cane disease as caused by a complex of different phytopathogenic fungi. Moreover, several fungal species can survive as saprophytes on canes with a role in disease development (Girichev et al 2018). Thus, it is necessary to clearly understand the etiology of raspberry cane blight to identify the fungal species associated with symptomatic or asymptomatic plant materials and their role in the disease development.…”

Insights into the susceptibility of raspberries to Drosophila suzukii oviposition

“…Future work could focus on further evaluation since many other raspberry cultivars (Girichev et al, 2018) have not been evaluated yet. Considering genetic diversity of Rubus genetic resources, the results obtained by Girichev et al (2017) indicate that genetic diversity in German raspberry germplasm is narrow.…”

Field apple scab susceptibility of a diverse Malus germplasm collection identifies potential sources of resistance for apple breeding

“…Malus accessions and land races maintained in the US national germplasm repository are sources of diverse functional alleles that can be used to breed apple cultivars with enhanced and durable resistance (Byrne et al 2018). In fact, large-scale screening of germplasm repositories is a common strategy to identify valuable traits for use in breeding for many major crop species (Girichev et al 2018;Liang et al 2015;Vasudevan et al 2014). Conventional commercial apple production is driven mainly by desirable fruit quality traits including taste and shelf life, but development of new apple scab resistant, or tolerant, cultivars might allow reduction of disease management costs, fungicide resistance development, as well as reduce negative environmental and health impacts, and is especially critical for organic and low input production (Koutis et al 2018;Kellerhals et al 2004).…”