Abstract
Resistance to chemistries of the succinate dehydrogenase inhibiting (SDHI) and quinone outside inhibiting (QoI) fungicides has developed rapidly in populations of Alternaria solani, the cause of early blight of potato. Reduced sensitivity to the anilinopyrimidine (AP) fungicide pyrimethanil has also been identified recently, determining that resistance to three chemical classes of fungicides is present within the A. solani population. Although no mutations have been characterized to confer resistance to APs, in A. solani five point mutations on three AsSdh genes have been determined to convey resistance to SDHIs, and the substitution of phenylalanine with leucine at position 129 (F129L) in the cytb gene confers resistance to QoIs. The objective of this study was to investigate the parasitic fitness of A. solani isolates with resistance to one or more of these chemical classes. A total of 120 A. solani isolates collected from various geographical locations around the United States were chosen for in vitro assessment, and 60 of these isolates were further evaluated in vivo. Fitness parameters measured were (i) spore germination in vitro, (ii) mycelial expansion in vitro, and (iii) aggressiveness in vivo. No significant differences in spore germination or mycelial expansion (P = 0.44 and 0.51, respectively) were observed among wild-type and fungicide-resistant isolates in vitro. Only A. solani isolates possessing the D123E mutation were shown to be significantly more aggressive in vivo (P < 0.0001) compared with wild-type isolates. These results indicate that fungicide-resistant A. solani isolates have no significant fitness penalties compared with sensitive isolates under the parameters evaluated regardless of the presence or absence of reduced sensitivity to multiple chemical classes. Results of these studies suggest that A. solani isolates with multiple fungicide resistances may compete successfully with wild-type isolates under field conditions.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 4
Claim · model-written summary
Resistant and wild-type isolates did not differ significantly in spore germination.
- Taxon
- potato
Solanum tuberosume1 - Interactor
- fungicide-resistant isolatese0pathogen
- Outcome
- spore germinatione0
- Direction
- No significant differencese0
- Comparator
- wild-typee0
- Setting
- in vitroe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“No significant differences in spore germination or mycelial expansion (P = 0.44 and 0.51, respectively) were observed among wild-type and fungicide-resistant isolates in vitro.”
e1“early blight of potato”
t0“Alternaria solani”
Claim · model-written summary
Resistant and wild-type isolates did not differ significantly in mycelial expansion.
- Taxon
- potatoSolanum tuberosume1
- Interactor
- fungicide-resistant isolatese0pathogen
- Outcome
- mycelial expansione0
- Direction
- No significant differencese0
- Comparator
- wild-typee0
- Setting
- in vitroe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“No significant differences in spore germination or mycelial expansion (P = 0.44 and 0.51, respectively) were observed among wild-type and fungicide-resistant isolates in vitro.”
e1“early blight of potato”
t0“Alternaria solani”
Claim · model-written summary
D123E isolates were more aggressive than wild-type isolates in vivo.
- Taxon
- potatoSolanum tuberosume1
- Interactor
- A. solani
Alternaria solanie0pathogen - Gene
- D123Ee0
- Outcome
- aggressivee0
- Direction
- more aggressivee0
- Comparator
- wild-type isolatese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Only A. solani isolates possessing the D123E mutation were shown to be significantly more aggressive in vivo (P < 0.0001) compared with wild-type isolates.”
e1“early blight of potato”
t0“Alternaria solani”
Claim · model-written summary
Resistant isolates had no significant fitness penalty under the evaluated parameters.
- Taxon
- potatoSolanum tuberosume1
- Interactor
- A. solaniAlternaria solanie0pathogen
- Outcome
- fitness penaltiese0
- Direction
- no significante0
- Comparator
- sensitive isolatese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“fungicide-resistant A. solani isolates have no significant fitness penalties compared with sensitive isolates under the parameters evaluated regardless of the presence or absence of reduced sensitivity to multiple chemical classes.”
e1“early blight of potato”
t0“Alternaria solani”