Abstract
Astragalus schanginianus (Fabaceae), a perennial herbaceous plant native to Xinjiang, plays a key role in natural grassland ecosystems through nitrogen fixation and soil stabilization (Flora of China). In August 2023, root rot was observed in a natural grassland survey in Fuyun County (89°52'11.37"N, 47°13'24.45"E), China. Disease symptoms were observed on all surveyed plants (100% incidence, n = 15), which exhibited browning of the inner root tissues. Five diseased plants were randomly selected for tissue isolation. Root segments (3 mm3) were surface-disinfested (75% ethanol for 30 s, 1% NaClO for 60 s), rinsed three times with sterile water, dried with sterile filter paper, and subsequently cultured on potato dextrose agar (PDA) at 25°C, with three plates per plant and five explants per plate. Strains LYZ1593 and LYZ1594, which were isolated from different individual plants and exhibited consistent colony morphology, were purified by single-spore isolation for further study. On PDA, the isolates developed abundant white aerial mycelium and produced rose-colored diffusible pigmentation in the agar. Macroconidia were hyaline, slender, straight to slightly curved, 3 - 5 septa, measuring 28.6 ± 6.4 × 4.8 ± 0.8 μm (n = 30). Microconidia were fusiform, hyaline, 0 - 1 septum, measuring 9.1 ± 1.3 × 2.4 ± 0.4 μm (n = 30). Chlamydospores were globose, smooth-walled, formed in chains, measuring 9.7 ± 1.4 × 9.0 ± 2.3 μm (n = 15). Conidiogenous cells were monophialides. Based on these morphological characteristics, the fungus was provisionally identified as a Fusarium sp. (Lesli et al., 2006). For molecular identification, the ITS, RPB2, and EF1α genes were amplified with primers ITS1/ITS4 (White et al., 1990), fRPB2-5F/fRPB2-7cR (Liu et al., 1999), and EF1/EF2 (O'Donnell et al., 1998), respectively. The obtained sequences were compared against the FUSARIOID-ID database and revealed 100% identity of all three loci with F. acuminatum strain LC5227. A maximum-likelihood tree from concatenated sequences (MEGA7, Tamura et al., 2016) grouped the strains within F. acuminatum with 100% bootstrap support (1000 replicates). Sequences were deposited under accession numbers PX570701 to PX570702 (ITS); PX516689 to PX516690 (RPB2); and PX548366 to PX548367 (EF1α). Pathogenicity was assessed using the wound-free root dip method, sterile A. schanginianus seedlings (1 cm root length) were immersed in conidial suspension (1×10⁷ conidia/mL) of the representative strain LYZ1593 for 1 h, then transplanted into pots with a sterilized loam soil (dry-heat sterilized at 169°C for 2 h), with five seedlings per pot. Four pots per treatments (inoculated/control) were used, with two experimental replicates. Plants were maintained at 25 ± 2°C with 70% relative humidity. At 10 days post-transplanting, 20% of inoculated plants died, and by 30 days, all inoculated seedlings exhibited brown root lesions, while controls remained asymptomatic. The fungus reisolated from infected roots matched F. acuminatum morphologically and molecularly, fulfilling Koch’s postulates. To our knowledge, A. schanginianus has only been reported to be infected by Microsphaera astragali (Amano, 1986). This study represents the first report of F. acuminatum causing root rot in A. schanginianus, broadening our understanding of root rot pathogens in natural grassland legumes. This finding has implications for disease management in native plant communities.
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 7
Claim · model-written summary
All surveyed Astragalus schanginianus plants had root rot symptoms.
- Taxon
- Astragalus schanginianusAstragalus schanginianust0
- Organ / stage
- inner root tissuese0
- Interactor
- Fusarium acuminatum
Fusarium acuminatumt0pathogen - Outcome
- Disease symptomse0
- Value
- 100% incidencee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Disease symptoms were observed on all surveyed plants (100% incidence, n = 15), which exhibited browning of the inner root tissues.”
t0“Fusarium acuminatum Causing Astragalus schanginianus Root Rot”
Claim · model-written summary
Fungal isolates from diseased Astragalus roots matched F. acuminatum at all three loci.
- Taxon
- Astragalus schanginianusAstragalus schanginianust0
- Interactor
- F. acuminatumFusarium acuminatume0pathogen
- Outcome
- 100% identity of all three locie0
- Value
- 100%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The obtained sequences were compared against the FUSARIOID-ID database and revealed 100% identity of all three loci with F. acuminatum strain LC5227.”
t0“Astragalus schanginianus Root Rot”
Claim · model-written summary
Phylogenetic analysis grouped the isolates within F. acuminatum with full bootstrap support.
- Taxon
- Astragalus schanginianusAstragalus schanginianust0
- Interactor
- F. acuminatumFusarium acuminatume0pathogen
- Outcome
- grouped the strains within F. acuminatume0
- Value
- 100% bootstrap supporte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A maximum-likelihood tree from concatenated sequences (MEGA7, Tamura et al., 2016) grouped the strains within F. acuminatum with 100% bootstrap support (1000 replicates).”
t0“Astragalus schanginianus Root Rot”
Claim · model-written summary
Twenty percent of inoculated seedlings died by day 10.
- Taxon
- Astragalus schanginianusAstragalus schanginianust0
- Treatment
- inoculated plantse0
- Interactor
- Fusarium acuminatumFusarium acuminatumt0pathogen
- Outcome
- plants diede0
- Value
- 20%e0
- Comparator
- controlse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At 10 days post-transplanting, 20% of inoculated plants died, and by 30 days, all inoculated seedlings exhibited brown root lesions, while controls remained asymptomatic.”
t0“Fusarium acuminatum Causing Astragalus schanginianus Root Rot”
Claim · model-written summary
All inoculated seedlings developed brown root lesions by day 30, while controls stayed asymptomatic.
- Taxon
- Astragalus schanginianusAstragalus schanginianust0
- Treatment
- inoculated seedlingse0
- Interactor
- Fusarium acuminatumFusarium acuminatumt0pathogen
- Outcome
- brown root lesionse0
- Comparator
- controlse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“by 30 days, all inoculated seedlings exhibited brown root lesions, while controls remained asymptomatic.”
t0“Fusarium acuminatum Causing Astragalus schanginianus Root Rot”
Claim · model-written summary
The pathogen was reisolated from infected roots, satisfying Koch’s postulates.
- Taxon
- Astragalus schanginianusAstragalus schanginianust0
- Interactor
- F. acuminatumFusarium acuminatume0pathogen
- Outcome
- matched F. acuminatum morphologically and molecularlye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The fungus reisolated from infected roots matched F. acuminatum morphologically and molecularly, fulfilling Koch’s postulates.”
t0“Astragalus schanginianus Root Rot”
Claim · model-written summary
This is reported as the first occurrence of F. acuminatum root rot in Astragalus schanginianus.
- Taxon
- A. schanginianusAstragalus schanginianuse0
- Interactor
- F. acuminatumFusarium acuminatume0pathogen
- Outcome
- first report of F. acuminatum causing root rote0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This study represents the first report of F. acuminatum causing root rot in A. schanginianus”