Somatic Hybrids Between Potato and S. berthaultii Show Partial Resistance to Soil‐Borne Fungi and Potato Virus Y

Abstract

Three tetraploid somatic hybrid lines produced by protoplast fusion between a dihaploid potato, Solanum tuberosum, cultivar BF15 and the wild potato species Solanum berthaultii were evaluated here for their response to different soil‐borne pathogens, that is Fusarium solani, Pythium aphanidermatum and Rhizoctonia solani as well as to infection by potato virus Y (PVY). Both hybrid and BF15 plants grown in vitro were inoculated with the tested pathogen strains, that is R. solani, P. aphanidermatum, or F. solani. The growth level and disease severity index of these plants were compared to the susceptible commercial cultivar Spunta. A better growth of inoculated hybrid plants and restricted disease symptoms were observed in comparison with the commercial plants. Under glasshouse conditions and after inoculation with R. solani and P. aphanidermatum, improved resistance of the hybrid plants to these pathogens was confirmed. Indeed, these plants showed no significant damage following inoculation and a better development in R. solani‐infected plants. The susceptibility of the hybrid tubers to R. solani, P. aphanidermatum, and to F. solani infection was also determined. A significant reduction of tissue colonisation was observed in all the hybrid lines compared to the cultivated cultivars. The STBc and STBd hybrids also showed improved resistance to the PVY ordinary strain (PVYo) under glasshouse conditions.

PCR-based markers developed by comparison of complete chloroplast genome sequences discriminateSolanum chacoensefrom otherSolanumspecies

“…These conditions cause sexual incompatibility between S. chacoense and potato and restrict the utilization of the wild species in classical potato breeding (Cho et al 1997;Oritz and Ehlenfeldt 1992). Therefore, protoplast fusion was used with the two different species for crop improvement to overcome this sexual barrier for transferring certain interspecific genes from wild species into potato (Bidani et al 2007;Nouri-Ellouz et al 2016). Interspecific somatic hybrids between wild species such as S. nigrum, S. brevidens, S. phureja, and S. commersonii and potato were successfully produced in potato breeding (Barsby et al 1984;Binding et al 1982;Kim-Lee et al 2005;Putie et al 1986) and this technique has also been applied in between S. tuberosum and S. chaconese (Chen et al 2013).…”

Development of PCR-based markers for discriminating Solanum berthaultii using its complete chloroplast genome sequence

“…The species has been known as one of the important resources for resistance to several important pathogens such as Phytophthora infestans, potato virus Y etc. in potato breeding (Ewing et al 2000;Nouri-Ellouz et al 2016;Park et al 2009;Rauscher et al 2010;Tan et al 2010). On the other hand, sexual incompatibility caused by the different ploidy levels of the genome and endosperm balance number (EBN) between this wild species and potato have restricted the utilization of this wild species for improvements during classical breeding processes (Cho et al 1997;Oritz and Ehlenfeldt 1992).…”

“…On the other hand, sexual incompatibility caused by the different ploidy levels of the genome and endosperm balance number (EBN) between this wild species and potato have restricted the utilization of this wild species for improvements during classical breeding processes (Cho et al 1997;Oritz and Ehlenfeldt 1992). To overcome this sexual barrier for interspecific gene transfer, therefore, protoplast fusion has been attempted with the two different species for crop improvement (Bidani et al 2007;Nouri-Ellouz et al 2016). In potato breeding, this technique has also been applied and succeeded in producing interspecific somatic hybrids such as S. tuberosum (+) S. chaconese (Chen et al 2013), S. tuberosum (+) S. brevidens (Barsby et al 1984), S. tuberosum (+) S. nigrum (Binding et al 1982), S. tuberosum (+) S. phureja (Putie et al 1986) and S. tuberosum (+) S. commersonii (Kim-Lee et al 2005).…”

Chloroplast genome sequence of the wild tetraploid potato relativeSolanum stoloniferum

“…However, the species is sexually incompatible with S. tuberosum due to different endosperm balance numbers (EBNs) with EBN values of 2 and 4 in S. stoloniferum and S. tuberosum, respectively, although both species are tetraploid (Brown 1988;Singsit and Hanneman 1991;Ortiz and Ehlenfeldt 1992;Cho et al 1997). So, the wild species is difficult to be applied to potato breeding and somatic hybridization could be one of the solutions to overcome sexual barriers for interspecific gene transfer (Bidani et al 2007;Nouri-Ellouz et al 2016) and importance to identify chlorotype with information of chloroplast genome sequences in potato breeding program has increased (Chen et al 2013(Chen et al , 2016Moln ar et al 2017).…”

“… 2007 ; Nouri-Ellouz et al. 2016 ) and importance to identify chlorotype with information of chloroplast genome sequences in potato breeding program has increased (Chen et al. 2013 , 2016 ; Cho and Park 2016 ; Cho et al.…”