Variability of Peronosclerospora sorghi isolates from different geographic locations and hosts in Africa

Nine isolates of Peronosclerospora sorghi from maize, sorghum and wild sorghum were sampled from Zimbabwe, Zambia, Rwanda, Mozambique and Kenya. They were compared for variation in conidium and conidiophore morphology, temperature requirements for sporulation, germination and germ-tube growth and fo...

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Main Authors: Bock, C.H., Jeger, M.J., Mughogho, L.K., Cardwell, K., Mtisi, E., Kaula, G., Mukansabimana, D.
Format: Journal Article
Language:Inglés
Published: 2000
Subjects:
Online Access:https://hdl.handle.net/10568/99842
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author Bock, C.H.
Jeger, M.J.
Mughogho, L.K.
Cardwell, K.
Mtisi, E.
Kaula, G.
Mukansabimana, D.
author_browse Bock, C.H.
Cardwell, K.
Jeger, M.J.
Kaula, G.
Mtisi, E.
Mughogho, L.K.
Mukansabimana, D.
author_facet Bock, C.H.
Jeger, M.J.
Mughogho, L.K.
Cardwell, K.
Mtisi, E.
Kaula, G.
Mukansabimana, D.
author_sort Bock, C.H.
collection Repository of Agricultural Research Outputs (CGSpace)
description Nine isolates of Peronosclerospora sorghi from maize, sorghum and wild sorghum were sampled from Zimbabwe, Zambia, Rwanda, Mozambique and Kenya. They were compared for variation in conidium and conidiophore morphology, temperature requirements for sporulation, germination and germ-tube growth and for pathogenicity on different sorghum and maize cultivars. Although there were significant differences in isolate morphology, all conformed to the known range for P. sorghi. Mean conidial length×width ranged from 21–23 μm×16•9–19•2 μm, and mean conidiophore length (basal cell-branching) ranged from 116•3–135•6 μm. All isolates sporulated in the range 14–26 °C (optimal at 16–23°), although one isolate from maize from Umbeluzi in Mozambique had a broader optimal range for sporulation (12–25°). Conidia of all isolates germinated between 10° and 34°. Germ-tube response to temperature was similar for all isolates (10–34°). The isolates varied in their pathogenicity towards sorghum cultivars, with an isolate from Rwanda being pathogenic to more sorghum differentials than any other. Cluster analysis of isolates based on host reaction indicated five groups at the 85% similarity level. The existence of pathogenic variability has ramifications for the breeding of sorghum for resistance to downy mildew in Africa.
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spelling CGSpace998422023-12-08T19:25:22Z Variability of Peronosclerospora sorghi isolates from different geographic locations and hosts in Africa Bock, C.H. Jeger, M.J. Mughogho, L.K. Cardwell, K. Mtisi, E. Kaula, G. Mukansabimana, D. maize sorghum pathogens breeding Nine isolates of Peronosclerospora sorghi from maize, sorghum and wild sorghum were sampled from Zimbabwe, Zambia, Rwanda, Mozambique and Kenya. They were compared for variation in conidium and conidiophore morphology, temperature requirements for sporulation, germination and germ-tube growth and for pathogenicity on different sorghum and maize cultivars. Although there were significant differences in isolate morphology, all conformed to the known range for P. sorghi. Mean conidial length×width ranged from 21–23 μm×16•9–19•2 μm, and mean conidiophore length (basal cell-branching) ranged from 116•3–135•6 μm. All isolates sporulated in the range 14–26 °C (optimal at 16–23°), although one isolate from maize from Umbeluzi in Mozambique had a broader optimal range for sporulation (12–25°). Conidia of all isolates germinated between 10° and 34°. Germ-tube response to temperature was similar for all isolates (10–34°). The isolates varied in their pathogenicity towards sorghum cultivars, with an isolate from Rwanda being pathogenic to more sorghum differentials than any other. Cluster analysis of isolates based on host reaction indicated five groups at the 85% similarity level. The existence of pathogenic variability has ramifications for the breeding of sorghum for resistance to downy mildew in Africa. 2000 2019-03-03T05:53:29Z 2019-03-03T05:53:29Z Journal Article https://hdl.handle.net/10568/99842 en Limited Access Bock, C.H., Jeger, M.J., Mughogho, L.K., Cardwell, K., Mtisi, E., Kaula, G. & Mukansabimana, D. (2000). Variability of Peronosclerospora sorghi isolates from different geographic locations and hosts in Africa. Mycological Research, 104(1), 61-68.
spellingShingle maize
sorghum
pathogens
breeding
Bock, C.H.
Jeger, M.J.
Mughogho, L.K.
Cardwell, K.
Mtisi, E.
Kaula, G.
Mukansabimana, D.
Variability of Peronosclerospora sorghi isolates from different geographic locations and hosts in Africa
title Variability of Peronosclerospora sorghi isolates from different geographic locations and hosts in Africa
title_full Variability of Peronosclerospora sorghi isolates from different geographic locations and hosts in Africa
title_fullStr Variability of Peronosclerospora sorghi isolates from different geographic locations and hosts in Africa
title_full_unstemmed Variability of Peronosclerospora sorghi isolates from different geographic locations and hosts in Africa
title_short Variability of Peronosclerospora sorghi isolates from different geographic locations and hosts in Africa
title_sort variability of peronosclerospora sorghi isolates from different geographic locations and hosts in africa
topic maize
sorghum
pathogens
breeding
url https://hdl.handle.net/10568/99842
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