Distribution of Botrytis isolates associated with onion gray-mold neck rot in Hokkaido, northern Japan
- PDF / 1,072,895 Bytes
- 7 Pages / 595.276 x 790.866 pts Page_size
- 74 Downloads / 160 Views
FUNGAL DISEASES
Distribution of Botrytis isolates associated with onion gray‑mold neck rot in Hokkaido, northern Japan Ayumi Notsu1 · Kayo Shirai2 · Fujio Kodama3 · Norio Kondo4 Received: 23 November 2019 / Accepted: 8 June 2020 © The Phytopathological Society of Japan and Springer Japan KK, part of Springer Nature 2020
Abstract Gray-mold neck rot is an important disease affecting onion (Allium cepa L.) production areas in Japan including Hokkaido, the northernmost region. We examined 10 representative isolates of Botrytis spp. collected from onion bulbs with symptoms of gray-mold neck rot in Hokkaido from 2009 to 2012. We analyzed conidial morphology and the number of nuclei in these isolates. Polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) analysis was performed to identify the species. Five of the 10 isolates were identified as B. aclada; the remaining were identified as B. allii. From 2011 to 2017, we collected additional isolates from 50 fields in eight regions of Hokkaido and analyzed them with PCR–RFLP to clarify the distribution of Botrytis spp. Of the total 89 isolates, 63 were identified as B. allii and the remaining as B. aclada. B. allii was isolated from all eight regions of Hokkaido, whereas B. aclada was isolated from six regions, demonstrating the wide distribution of both species in Hokkaido and the tendency for B. allii to dominate. An inoculation test revealed the two species were pathogenic on onion bulbs. This report is the first of B. aclada causing onion gray-mold neck rot in Japan. Keywords Allium cepa · Botrytis aclada · Botrytis allii · Gray-mold neck rot
Introduction Onion (Allium cepa L.) is an important vegetable crop in Japan, with approximately 1,099,000 metric tons harvested from 25,600 ha during the 2017 growing season. Hokkaido, the northernmost region of Japan, is a major onion-producing area in the country. Typically, seedlings are grown in a greenhouse and transplanted into open fields as 2-month-old seedlings in late April to early May; plants are then harvested from August to September. The other main onion production areas are Hyogo and Saga Prefectures in western Japan. In the 2017 growing season, 14,600 ha of onions were cultivated in Hokkaido, 1,710 ha in Hyogo, and 2,160 ha in * Ayumi Notsu notsu‑[email protected] 1
Central Agricultural Experiment Station, Hokkaido Research Organization, Naganuma, Hokkaido 069‑1395, Japan
2
Tokachi Agricultural Experiment Station, Hokkaido Research Organization, Memuro, Hokkaido 082‑0081, Japan
3
Hokkaido Plant Protection Association, Sapporo, Hokkaido 060‑0001, Japan
4
Research Faculty of Agriculture, Hokkaido University, Sapporo 060‑8589, Japan
Saga Prefectures. In many areas of Japan, except in Hokkaido, onions are planted in the field in autumn and harvested in spring. In Hokkaido, several Botrytis species are associated with diseases on onion leaves. Of these Botrytis species, Botrytis allii Munn is known as the causal agent of gray-mold neck rot (NARO Genebank 2020). Botrytis leaf b
Data Loading...
