TY - JOUR
T1 - Differences in the Characteristics and Pathogenicity of Pyrenophora Species Associated with Seeds of Italian Ryegrass
AU - Xue, Longhai
AU - Xu, Zhiting
AU - Liu, Jiaqi
AU - Chen, Hao
AU - White, James F.
AU - Malik, Kamran
AU - Li, Chunjie
N1 - Publisher Copyright:
© 2023 American Phytopathological Society. All rights reserved.
PY - 2023/3
Y1 - 2023/3
N2 - Pyrenophora is a genus of pathogens that cause leaf damage and a common seedborne fungus of Italian ryegrass (Lolium multiflorum Lam.). To elucidate the main seedborne Pyrenophora species, 36 seed samples of Italian ryegrass were collected; in total, 113 strains, representing 12.3% of all isolated strains (921), were identified as Pyrenophora species using the identity of ITS sequences in NCBI and the similarity of morphological characteristics. P. dictyoides (97) was the most frequent species. By pure culture technique, 24 representative pure isolateswere obtained for further study. Based on DNA analysis of multiple loci (ITS, LSU, GPDH, CHS-1, and RPB1) and morphological characters, eight Pyrenophora species were identified, P. avenicola, P. chaetomioides, P. dictyoides, P. lolii, P. nobleae, P. teres, P. triseptata, and P. tritici-repentis; among them, P. avenicola, P. tritici-repentis, and P. triseptata were newly reported on Italian ryegrass worldwide. Seed inoculation showed that P. dictyoides, P. lolii, and P. teres remarkably decreased the final germination percentages and germination indexes compared with control treatments (P ≤ 0.05); and plant inoculation showed that P. dictyoides, P. lolii, and P. nobleae could cause typical brown spot in vivo with a higher infection rate (P ≤ 0.05). In conclusion, pathogenicity tests showed that all Pyrenophora species could both inhibit seed germination and infect Italian ryegrass to different degrees; among them, P. dictyoides was the most important seedborne pathogen based on the combination of its isolation and infection rate, followed by P. lolii and P. nobleae. The data generated in this study are helpful for the accurate identification of Pyrenophora species and the development of seedborne disease management strategies.
AB - Pyrenophora is a genus of pathogens that cause leaf damage and a common seedborne fungus of Italian ryegrass (Lolium multiflorum Lam.). To elucidate the main seedborne Pyrenophora species, 36 seed samples of Italian ryegrass were collected; in total, 113 strains, representing 12.3% of all isolated strains (921), were identified as Pyrenophora species using the identity of ITS sequences in NCBI and the similarity of morphological characteristics. P. dictyoides (97) was the most frequent species. By pure culture technique, 24 representative pure isolateswere obtained for further study. Based on DNA analysis of multiple loci (ITS, LSU, GPDH, CHS-1, and RPB1) and morphological characters, eight Pyrenophora species were identified, P. avenicola, P. chaetomioides, P. dictyoides, P. lolii, P. nobleae, P. teres, P. triseptata, and P. tritici-repentis; among them, P. avenicola, P. tritici-repentis, and P. triseptata were newly reported on Italian ryegrass worldwide. Seed inoculation showed that P. dictyoides, P. lolii, and P. teres remarkably decreased the final germination percentages and germination indexes compared with control treatments (P ≤ 0.05); and plant inoculation showed that P. dictyoides, P. lolii, and P. nobleae could cause typical brown spot in vivo with a higher infection rate (P ≤ 0.05). In conclusion, pathogenicity tests showed that all Pyrenophora species could both inhibit seed germination and infect Italian ryegrass to different degrees; among them, P. dictyoides was the most important seedborne pathogen based on the combination of its isolation and infection rate, followed by P. lolii and P. nobleae. The data generated in this study are helpful for the accurate identification of Pyrenophora species and the development of seedborne disease management strategies.
KW - Lolium multiflorum
KW - Pyrenophora species
KW - multiple loci
KW - seedborne
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U2 - 10.1094/PDIS-08-22-1753-RE
DO - 10.1094/PDIS-08-22-1753-RE
M3 - Article
C2 - 35939752
AN - SCOPUS:85152113156
SN - 0191-2917
VL - 107
SP - 758
EP - 770
JO - Plant disease
JF - Plant disease
IS - 3
ER -