Identification and Characterization of <i>Colletotrichum</i> Species Causing Sorghum Anthracnose in Kenya and Screening of Sorghum Germplasm for Resistance to Anthracnose
Anthracnose caused by <i>Colletotrichum</i> species is one of the most destructive fungal diseases of sorghum with annual yield losses of up to 100%. Although the resistance to anthracnose has been identified elsewhere, the usefulness of the resistance loci differs depending on the patho...
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| Format: | Article |
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MDPI AG
2023-01-01
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| Series: | Journal of Fungi |
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| Online Access: | https://www.mdpi.com/2309-608X/9/1/100 |
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| author | Irene Njeri Koima Dora Chao Kilalo Charles O. Orek John Maina Wagacha Evans N. Nyaboga |
| author_facet | Irene Njeri Koima Dora Chao Kilalo Charles O. Orek John Maina Wagacha Evans N. Nyaboga |
| author_sort | Irene Njeri Koima |
| collection | DOAJ |
| description | Anthracnose caused by <i>Colletotrichum</i> species is one of the most destructive fungal diseases of sorghum with annual yield losses of up to 100%. Although the resistance to anthracnose has been identified elsewhere, the usefulness of the resistance loci differs depending on the pathogen species and pathotypes. Accurate species identification of the disease-causing fungal pathogens is essential for developing and implementing suitable management strategies. The use of host resistance is the most effective strategy of anthracnose management and therefore identification of sources for resistance against unique pathogen pathotypes is fundamental. The aims of this study were to identify and characterize <i>Colletotrichum</i> species associated with sorghum anthracnose and screen sorghum germplasm for resistance to anthracnose. Symptomatic sorghum leaf samples were collected from smallholder farmers in lower eastern Kenya and used for the isolation, identification and characterization of <i>Colletotrichum</i> species using morpho-cultural and phylogenetic analyses with the sequences of the rDNA internal transcribed spacer (ITS) region. Pathogenicity tests of the seven fungal isolates showed that there were no significant differences in the pathogenicity on host plants. The fungal isolates were variable in cultural and morphological characters such as colony type and color, colony diameter, mycelia growth and hyaline. The phenotypic characters observed were useful in the identification of the genus Colletotrichum and not the species. Based on the sequence and phylogenetic analysis of ITS, <i>Colletotrichum sublineola</i> was revealed to be associated with anthracnose on sorghum. Germplasm screening for resistance to anthracnose showed differential reactions of sorghum genotypes to anthracnose under greenhouse and field conditions. The results revealed four resistant genotypes and ten susceptible genotypes against <i>Colletotrichum sublineola</i>. Significant (<i>p</i> ≤ 0.05) differences were observed in grain weight, grain yield, weight of 100 seeds and harvest index among the tested sorghum genotypes. The present study indicated that the Kenyan accessions could be an important source of resistance to anthracnose. The findings from this study provide a platform towards devising efficient disease control strategies and resistance breeding. |
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| format | Article |
| id | doaj.art-608fa622157346ef8ef541e3479241a1 |
| institution | Directory Open Access Journal |
| issn | 2309-608X |
| language | English |
| last_indexed | 2024-03-09T12:03:39Z |
| publishDate | 2023-01-01 |
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| spelling | doaj.art-608fa622157346ef8ef541e3479241a12023-11-30T23:00:19ZengMDPI AGJournal of Fungi2309-608X2023-01-019110010.3390/jof9010100Identification and Characterization of <i>Colletotrichum</i> Species Causing Sorghum Anthracnose in Kenya and Screening of Sorghum Germplasm for Resistance to AnthracnoseIrene Njeri Koima0Dora Chao Kilalo1Charles O. Orek2John Maina Wagacha3Evans N. Nyaboga4Department of Plant Science and Crop Protection, University Nairobi, P.O. Box 29053, Nairobi 00625, KenyaDepartment of Plant Science and Crop Protection, University Nairobi, P.O. Box 29053, Nairobi 00625, KenyaDepartment of Agricultural Sciences, South Eastern Kenya University, P.O. Box 170, Kitui 90200, KenyaDepartment of Biology, University Nairobi, P.O. Box 30197, Nairobi 00100, KenyaDepartment of Biochemistry, University Nairobi, P.O. Box 30197, Nairobi 00100, KenyaAnthracnose caused by <i>Colletotrichum</i> species is one of the most destructive fungal diseases of sorghum with annual yield losses of up to 100%. Although the resistance to anthracnose has been identified elsewhere, the usefulness of the resistance loci differs depending on the pathogen species and pathotypes. Accurate species identification of the disease-causing fungal pathogens is essential for developing and implementing suitable management strategies. The use of host resistance is the most effective strategy of anthracnose management and therefore identification of sources for resistance against unique pathogen pathotypes is fundamental. The aims of this study were to identify and characterize <i>Colletotrichum</i> species associated with sorghum anthracnose and screen sorghum germplasm for resistance to anthracnose. Symptomatic sorghum leaf samples were collected from smallholder farmers in lower eastern Kenya and used for the isolation, identification and characterization of <i>Colletotrichum</i> species using morpho-cultural and phylogenetic analyses with the sequences of the rDNA internal transcribed spacer (ITS) region. Pathogenicity tests of the seven fungal isolates showed that there were no significant differences in the pathogenicity on host plants. The fungal isolates were variable in cultural and morphological characters such as colony type and color, colony diameter, mycelia growth and hyaline. The phenotypic characters observed were useful in the identification of the genus Colletotrichum and not the species. Based on the sequence and phylogenetic analysis of ITS, <i>Colletotrichum sublineola</i> was revealed to be associated with anthracnose on sorghum. Germplasm screening for resistance to anthracnose showed differential reactions of sorghum genotypes to anthracnose under greenhouse and field conditions. The results revealed four resistant genotypes and ten susceptible genotypes against <i>Colletotrichum sublineola</i>. Significant (<i>p</i> ≤ 0.05) differences were observed in grain weight, grain yield, weight of 100 seeds and harvest index among the tested sorghum genotypes. The present study indicated that the Kenyan accessions could be an important source of resistance to anthracnose. The findings from this study provide a platform towards devising efficient disease control strategies and resistance breeding.https://www.mdpi.com/2309-608X/9/1/100anthracnose<i>Colletotrichum sublineola</i>internal transcribed spacerresistancesorghum |
| spellingShingle | Irene Njeri Koima Dora Chao Kilalo Charles O. Orek John Maina Wagacha Evans N. Nyaboga Identification and Characterization of <i>Colletotrichum</i> Species Causing Sorghum Anthracnose in Kenya and Screening of Sorghum Germplasm for Resistance to Anthracnose Journal of Fungi anthracnose <i>Colletotrichum sublineola</i> internal transcribed spacer resistance sorghum |
| title | Identification and Characterization of <i>Colletotrichum</i> Species Causing Sorghum Anthracnose in Kenya and Screening of Sorghum Germplasm for Resistance to Anthracnose |
| title_full | Identification and Characterization of <i>Colletotrichum</i> Species Causing Sorghum Anthracnose in Kenya and Screening of Sorghum Germplasm for Resistance to Anthracnose |
| title_fullStr | Identification and Characterization of <i>Colletotrichum</i> Species Causing Sorghum Anthracnose in Kenya and Screening of Sorghum Germplasm for Resistance to Anthracnose |
| title_full_unstemmed | Identification and Characterization of <i>Colletotrichum</i> Species Causing Sorghum Anthracnose in Kenya and Screening of Sorghum Germplasm for Resistance to Anthracnose |
| title_short | Identification and Characterization of <i>Colletotrichum</i> Species Causing Sorghum Anthracnose in Kenya and Screening of Sorghum Germplasm for Resistance to Anthracnose |
| title_sort | identification and characterization of i colletotrichum i species causing sorghum anthracnose in kenya and screening of sorghum germplasm for resistance to anthracnose |
| topic | anthracnose <i>Colletotrichum sublineola</i> internal transcribed spacer resistance sorghum |
| url | https://www.mdpi.com/2309-608X/9/1/100 |
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