First Report of Pestalotiopsis lushanensis Causing Black Leaf Spot on Italian Ryegrass in China

Italian ryegrass (Lolium multiflorum) is widely grown for forage in Southwest China. In December 2023, black leaf spots were observed on Italian ryegrass in a 10 hm2 field in Hongya County, Sichuan Province, China (29°52'11''°N, 103°16'16''°E). The disease developed spo...

Ausführliche Beschreibung

Bibliographische Detailangaben
Veröffentlicht in:Plant disease. - 1997. - (2024) vom: 21. Nov.
1. Verfasser: Long, Jiahui (VerfasserIn)
Weitere Verfasser: Xu, Lingling, Cui, Huawei, Kamran, Malik, Liu, Jiaqi, Xue, Longhai, Li, Chunjie, Li, Yan Zhong, Duan, Tingyu
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2024
Zugriff auf das übergeordnete Werk:Plant disease
Schlagworte:Journal Article Etiology Italian ryegrass Pestalotiopsis lushanensis Subject Areas black leaf spot
LEADER 01000naa a22002652 4500
001 NLM380571528
003 DE-627
005 20241122232808.0
007 cr uuu---uuuuu
008 241122s2024 xx |||||o 00| ||eng c
024 7 |a 10.1094/PDIS-11-24-2314-PDN  |2 doi 
028 5 2 |a pubmed24n1609.xml 
035 |a (DE-627)NLM380571528 
035 |a (NLM)39570758 
040 |a DE-627  |b ger  |c DE-627  |e rakwb 
041 |a eng 
100 1 |a Long, Jiahui  |e verfasserin  |4 aut 
245 1 0 |a First Report of Pestalotiopsis lushanensis Causing Black Leaf Spot on Italian Ryegrass in China 
264 1 |c 2024 
336 |a Text  |b txt  |2 rdacontent 
337 |a ƒaComputermedien  |b c  |2 rdamedia 
338 |a ƒa Online-Ressource  |b cr  |2 rdacarrier 
500 |a Date Revised 21.11.2024 
500 |a published: Print-Electronic 
500 |a Citation Status Publisher 
520 |a Italian ryegrass (Lolium multiflorum) is widely grown for forage in Southwest China. In December 2023, black leaf spots were observed on Italian ryegrass in a 10 hm2 field in Hongya County, Sichuan Province, China (29°52'11''°N, 103°16'16''°E). The disease developed sporadically with an incidence rate of < 1%. Leaves showed typical symptoms of small, black spots. For isolation, six samples (about 0.5 cm × 1 cm) were cut with a sterilized blade at the junction of diseased and healthy tissues from two different plants. They were surface disinfected in 75% ethanol for 40s, rinsed thrice in sterilized distilled water, air-dried, plated on potato dextrose agar (PDA), and incubated in the dark at 25°C for 3-7 days. A Pestalotiopsis-like fungus with similar colony characteristics was consistently isolated from all samples. Pure cultures were obtained with the single-spore technique (Cai et al. 2009), and two strains (LJH17 and LJH18) were selected for further study. After 5 days in the dark at 25°C, colonies on PDA were cottony, whitish, 70-78 mm in diameter, with an entire edge. The reverse side of the colonies appeared white to light yellow. Conidia were fusoid, straight to slightly curved, 4-septate, with 2-4 (mostly 3) tubular apical appendages, measuring 17.3 to 25 × 6.1 to 9.9 μm (mean ± SD = 20.7 ± 2.3 × 7.9 ± 0.7 µm; n = 50; LJH17). For further identification, the internal transcribed spacer regions 1 and 2 and 5.8S nuclear ribosomal RNA (ITS), partial β-tubulin (tub2) and translation elongation factor 1-α (tef1) genes from the two pure strains GMCC000083 (=LJH17; GMCC, Grassland Microbiome Culture Collection) and LJH18 were amplified with the primer pairs ITS1/ITS4 (White et al. 1990), T1/Bt2b (Glass and Donaldson 1995; O'Donnell and Cigelnik 1997), and EF1-728F/EF2 (Carbone and Kohn 1999; O'Donnell et al. 1998). Sequences were deposited in GenBank (PP779763, PP781949, and PP781950 for LJH17; and PQ013725, PQ015095, and PQ015096 for LJH18). BLAST analysis showed 100% identity across all three segments with ex-type isolate LC4344 of Pestalotiopsis lushanensis (Liu et al. 2017). A randomized accelerated maximum likelihood (RAxML) phylogenetic tree based on concatenated ITS, tub2, and tef1 alignments showed that our two strains clustered with the previously reported P. lushanensis strains ((Liu et al. 2017; Jiang et al. 2022) (Fig. S1F). Eight-week-old healthy plants were grown from Italian ryegrass seeds in pots, with three plants per pot. Following our previous spray inoculation procedures (Xue et al. 2020): fresh 5-day-old mycelia from each strain were prepared as mycelial suspensions at about 2.5 × 104 CFU/ml, and conidial suspensions were adjusted to about 2 × 105 conidia/ml. For each strain (LJH17 and LJH18), five pots were separately spray-inoculated with conidial and mycelial suspensions (about 2 ml/pot). Five pots served as non-inoculated controls were sprayed with sterilized distilled water. All pots were individually covered with transparent polyethylene bags for 5 days to maintain high relative humidity and placed in a greenhouse at 23-29°C. After incubation for 15 days, both conidial and mycelial suspensions produced black spots on the plants (Fig. S1), resembling those previously observed in the field. No symptoms were observed in the control plants. Pathogenicity tests were conducted thrice using the same method. The same fungus was reisolated from the lesions and confirmed via the morphological and molecular methods described above, thus fulfilling Koch' s postulates. To our knowledge, this is the first report of P. lushanensis causing black leaf spot on Italian ryegrass in China or worldwide. This finding may aid in diagnosing, identifying the pathogen, and controlling the disease on Italian ryegrass 
650 4 |a Journal Article 
650 4 |a Etiology 
650 4 |a Italian ryegrass 
650 4 |a Pestalotiopsis lushanensis 
650 4 |a Subject Areas 
650 4 |a black leaf spot 
700 1 |a Xu, Lingling  |e verfasserin  |4 aut 
700 1 |a Cui, Huawei  |e verfasserin  |4 aut 
700 1 |a Kamran, Malik  |e verfasserin  |4 aut 
700 1 |a Liu, Jiaqi  |e verfasserin  |4 aut 
700 1 |a Xue, Longhai  |e verfasserin  |4 aut 
700 1 |a Li, Chunjie  |e verfasserin  |4 aut 
700 1 |a Li, Yan Zhong  |e verfasserin  |4 aut 
700 1 |a Duan, Tingyu  |e verfasserin  |4 aut 
773 0 8 |i Enthalten in  |t Plant disease  |d 1997  |g (2024) vom: 21. Nov.  |w (DE-627)NLM098181742  |x 0191-2917  |7 nnns 
773 1 8 |g year:2024  |g day:21  |g month:11 
856 4 0 |u http://dx.doi.org/10.1094/PDIS-11-24-2314-PDN  |3 Volltext 
912 |a GBV_USEFLAG_A 
912 |a SYSFLAG_A 
912 |a GBV_NLM 
912 |a GBV_ILN_350 
951 |a AR 
952 |j 2024  |b 21  |c 11