Fusarium spp. associated with rice Bakanae: ecology, genetic diversity, pathogenicity and toxigenicity

Abstract

African and Asian populations of Fusarium spp. (Gibberella fujikuroi species complex) associated with Bakanae of rice (Oryzae sativa L.) were isolated from seeds and characterized with respect to ecology, phylogenetics, pathogenicity and mycotoxin production. Independent of the origin, Fusarium spp. were detected in the different rice seed samples with infection rate ranges that varied from 0.25% to 9%. Four Fusaria (F. andiyazi, F. fujikuroi, F. proliferatum and F. verticillioides) were found associated with Bakanae of rice. While three of the Fusaria were found in both African and Asian seed samples, F. fujikuroi was only detected in seed samples from Asia. Phylogenetic studies showed a broad genetic variation among the strains that were distributed into four different genetic clades. Pathogenicity tests showed that all strains reduced seed germination and possessed varying ability to cause symptoms of Bakanae on rice, some species (i.e. F. fujikuroi) being more pathogenic than others. The ability to produce fumonisins (FB(1) and FB(2)) and gibberellin A3 in vitro also differed according to the Fusarium species. While fumonisins were produced by most of the strains of F. verticillioides and F. proliferatum, gibberellin A3 was only produced by F. fujikuroi. Neither fumonisin nor gibberellin was synthesized by most of the strains of F. andiyazi. These findings provide new information on the variation within the G. fujikuroi species complex associated with rice seed and Bakanae disease.

Population Structure of the Gibberella fujikuroi Species Complex Associated with Rice and Corn in Korea

“…The most dramatic host preference was shown in F. verticillioides, which was the dominant species on corn although the frequency varied by the year of collection, as reported in Korea and other countries (Chung and Kim 1995;Desjardins et al, 2000;Park et al, 2001;Zainudin et al, 2008). Almost no contamination of F. verticillioides in rice was also consistent with the cases of other countries, although contamination frequencies were higher than in this study (Amatulli et al, 2010;Desjardins et al, 2000;Wulff et al, 2010;Zainudin et al, 2008). In contrast, F. fujikuroi, F. proliferatum, and F. concentricum were commonly recovered from both rice and corn.…”

“…In this respect, the pathogenicity of F. fujikuroi isolates toward rice should be determined in the future. Most F. fujikuroi isolates obtained here produced only small amount of fumonisins on rice substrate (Lee et al, unpublished data), as in other cases (Desjardins et al, 2000;Wulff et al, 2010;Zainudin et al, 2008).…”

“…Three fumonisin-producing species, F. fujikuroi (MP-C, teleomorph: G. fujikuroi), F. proliferatum (MP-D, G. intermedia), and F. verticillioides (MP-A, G. moniliformis), have been isolated from rice plants showing bakanae symptoms in Asia, Africa, Europe, and the United States (Amatulli et al, 2010;Carter et al, 2008;Desjardins et al, 2000;Desjardins et al, 1997;Hsuan et al, 2011;Wulff et al, 2010;Zainudin et al, 2008). The incidence of the latter was relatively lower than the first two species.…”

Synthesis, Anti-Phytopathogenic and DPPH Radical Scavenging Activities of C-Prenylated Acetophenones and Benzaldehydes

“…Botrytis cinerea is a fungus that affects many species of plants causing necrotic injuries in different plant tissues 7 . Gibberella fujikuroi is a filamentous fungus that causes the disease called "bakanae" in rice and other grasses; it is characterized by excessive growth of the plant and a reduction in the size and quality of the fruit, caused by the excessive production of the plant growth hormone, Gibberellin GA3 8 . Phytophthora cinnamomi is a phytopathogenic fungus that causes the disease "avocado root rot" and is the main phytosanitary problem of this fruit in Chile 9 .…”

Bakanae Disease Reduction Effect by Use of Silicate Coated Seed in Wet Direct-Seeded Rice

“…키다리병에 대한 효과 적인 방제법으로는 온탕침법이나 약제소독 (Park et al, 2003;Park et al, 2008)에 의한 종자소독제에 의존되지만 키다리 병원성의 새로운 균주의 분화로 기존 종자소독제에 대한 내성 Kim et al, 2010;Ogawa and Takeda, 1990;Park et al, 2009;Park et al, 2008;Wulff et al, 2010)때문에 매년 피해면적 증가에 따른 범국가적인 방제 대책이 강구되고 있다. 마늘 추출액에 의한 키다리방제효 과가 발표되어 친환경적인 방제약제개발 가능성도 제시되었 으나 (Sung and Choi, 2004 육상태를 광학현미경 400배 배율로 검경하였다.…”