Molecular and morphological identification of fungi causing canker and dieback diseases on Vangueria infausta (Burch) subsp. rotundata (Robyns) and Berchemia discolor (Klotzsch) Hemsl in lower Eastern Kenya

Abstract

Drought-tolerant multipurpose fruit trees Vangueria infausta (Burch) subsp. rotundata (Robyns) and Berchemia discolor (Klotzsch) Hemsl are native to Kenya. These fruit tree species are suitable for dryland agroforestry and support local communities with food, medicine, fodder and other necessities. Reports by the local communities indicate that the two species suffer from diebacks and cankers. The aim of this study was to identify the fungi associated with V. rotundata and B. discolor and determine the cause of diebacks and cankers symptoms observed. Samples were collected from two sites (Tiva and Ikanga) in Kitui County and one site (Mkange) in Makueni County. Fungal isolations were carried out by incubating the samples on malt extract agar media supplemented with Streptomycin Sulphate. Morphological identification grouped the fungal isolates into 7 clusters. Botryosphaeriaceae and Nectriaceae had the highest frequency of occurrence (32.7 and 30.5%) respectively. DNA was extracted from pure fungal cultures, amplified and sequenced. Phylogenetic analysis of DNA sequences clustered the fungal isolates into seven families; Botryosphaeriaceae, Sporocadaceae, Nectriaceae, Trichosphaeriaceae, Pleosporaceae, Diaporthaceae and Glomerellaceae. Using Koch's postulates, this study showed that isolates of Botryosphaeriaceae within the genera Lasiodiplodia, Alanphillipsia and Dothiorella are pathogenic to B. discolor and other indigenous agroforestry species due to their ability to cause similar symptoms to those observed in the field. This is the first study to investigate the fungal flora linked to V. rotundata and B. discolor dieback and canker diseases.

Effect of the application of vermicompost and millicompost humic acids about the soybean microbiome under water restriction conditions

“…Nectriaceae, Pleosporaceae and Trichosphaeriaceae are families of fungi that are pathogenic to Berchemia discolor, which is a drought-tolerant multipurpose tree with the potential to provide medicine, food and other commodities to drylands in several countries (Susan et al, 2022). Chaetomiaceae species are a wealthy source of enzymes with diverse biotechnological and industrial applications, such as PMO (polysaccharide monooxygenase), L-methioninase, β-1,3-glucanase, laccase, dextranase, lipolytic, pectinolytic, amylolytic, chitinolytic, and proteolytic enzymes.…”

Morpho-Phylogenetic Evidence Reveals Novel Species and New Records of Botryosphaeriaceae in China and Thailand

“…The results of this study indicate that there is still much potential for Botryosphaeriaceae members to be discovered in China and Thailand. As members of the Botryosphaeriaceae family represent a growing threat to agricultural crops and urban and natural forest ecosystems [75][76][77][78], this finding raises questions about the origin, introduction, and pathway of these fungi as well as underlining the need to develop suitable actions to limit their further spread.…”