Abstract
Common scab is a potato disease characterized by the formation of scab-like lesions on the surface of potato tubers. The actinobacterium Streptomyces scabiei is the main causal agent of common scab. During infection, this bacterium synthesizes the phytotoxin thaxtomin A which is essential for the production of disease symptoms. While thaxtomin A can activate an atypical programmed cell death in plant cell suspensions, it is possible to gradually habituate plant cells to thaxtomin A to provide resistance to lethal phytotoxin concentrations. Potato ‘Russet Burbank’ calli were habituated to thaxtomin A to regenerate the somaclone RB9 that produced tubers more resistant to common scab than those obtained from the original cultivar. Compared to the Russet Burbank cultivar, somaclone RB9 generated up to 22% more marketable tubers with an infected tuber area below the 5% threshold. Enhanced resistance was maintained over at least two years of cultivation in the field. However, average size of tubers was significantly reduced in somaclone RB9 compared to the parent cultivar. Small RB9 tubers had a thicker phellem than Russet Burbank tubers, which may contribute to improving resistance to common scab. These results show that thaxtomin A-habituation in potato is efficient to produce somaclones with increased and durable resistance to common scab.
Highlights
Common scab is a potato disease causing the formation of deep or superficial corky lesions on the surface of young developing tubers
Further molecular and biochemical characterization of the RB9 somaclone will be invaluable to identify the changes that made this TAhabituated somaclone more resistant to common scab compared to its genetically equivalent cultivar Russet Burbank. This may lead to the identification of specific phenotypic characteristics or molecular markers that are linked with resistance to common scab
Common scab evaluation of individual tubers from original ’Russet Burbank’ (RBP) and thaxtomin A (TA)-habituated somaclones cultivated in growth chamber (Trials 1, 2 and 3)
Summary
Common scab is a potato disease causing the formation of deep or superficial corky lesions on the surface of young developing tubers. This disease affects tuber market values as infected tubers with more than 5% of scab lesions on their surface are generally rejected by the industry. Several environmental conditions can promote the occurrence of common scab, making its management very complex. Approaches to control common scab include maintaining high soil moisture, changes in soil pH, crop rotation, soil fumigation and biological control, but these practices are not always successful
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
