ISOLATION AND CHARACTERIZATION OF BENOMYL-RESISTANT BIOTYPES OF THE DELTA RACE OF COLLETOTRICHUM LINDEMUTHIANUM

Thirteen biotypes resistant to benomyl and which were capable of radiating mycelial growth on Mathur’s agar (MA) containing 500 μg/mL of benomyl were isolated from race delta of bean anthracnose (Colletotrichum lindemuthianum). The resistance was of a persistent type, resistant characteristics being retained after several subculturings on benomyl-free MA. Several biotypes lost virulence totally or partially while the others increased in virulence. In addition, individual biotypes differed in pathogenicity towards various susceptible cultivars. The cultural characteristics, sporulation and growth differed among the biotypes and also from the original delta race. Pathogenicity generally was correlated positively for the virulent biotypes, with the amount of sporulation. The significance of the development of the resistant biotypes and the use of benomyl in seed treatment to control bean anthracnose is discussed.

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Occurrence and characterization of the alpha-Brazil race of bean anthracnose [Colletotrichum lindemuthianum] in Ontario

Canadian Journal of Plant Pathology ◽

10.1080/07060669409500770 ◽

1994 ◽

Vol 16 (2) ◽

pp. 129-131 ◽

Cited By ~ 9

Author(s):

J.C. Tu

Keyword(s):

Colletotrichum Lindemuthianum ◽

Bean Anthracnose

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Characterization of a Darkly Pigmented Mycelial Isolate of Sclerotinia sclerotiorum on Valencia Peanut in New Mexico

Plant Disease ◽

10.1094/pdis-91-9-1077 ◽

2007 ◽

Vol 91 (9) ◽

pp. 1077-1082 ◽

Cited By ~ 12

Author(s):

S. Sanogo ◽

N. Puppala

Keyword(s):

New Mexico ◽

Sclerotinia Sclerotiorum ◽

Mycelial Growth ◽

Culture Media ◽

Optimal Temperature ◽

Cultural Characteristics ◽

First Report ◽

Optimal Temperature Range ◽

Pathogenicity Tests

A sclerotia-forming fungus was isolated from a peanut field in eastern New Mexico, where Valencia peanut is grown. The isolated fungus was typified by its darkly pigmented mycelium when grown on culture media, with pigmentation influenced by media. The optimal temperature range for mycelial growth was 20 to 25°C. In pathogenicity tests, the fungus caused water-soaked and light tan lesions on stems at points of inoculation, and lesions progressed up the stems into petioles followed by collapse of leaves. White fluffy mycelium and sclerotia were present on inoculated plants. Based on the examination of morphological and cultural characteristics of sclerotia, apothecia, asci, and ascospores, the isolated fungus with darkly pigmented mycelium on culture media was identified as Sclerotinia sclerotiorum. This study is the first report of S. sclerotiorum on peanut in New Mexico.

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