Browsing by Author "Assefa, Teshale"

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    Characterization of phenotypic traits associated with anthracnose resistance in selected common bean (Phaseolus vulgaris L.) breeding material
    (Elsevier Ltd, 2024-02-27) Kadege, Edith; Venkataramana, Pavithravani; Assefa, Teshale; Ndunguru, Joseph; Rubyogo, Jean Claude; Mbega, Ernest
    Anthracnose caused by Colletotrichum lindemuthianum is the major common bean disease worldwide causing complete yield loss under favourable disease conditions. This study aimed to determine phenotypic traits associated with anthracnose resistance for future use in breeding programmes. Twenty-two common bean varieties (CBVs) were selected basing on susceptibility to anthracnose, advanced breeding lines, improved variety resembling advanced breeding lines and the farmer variety widely grown in Tanzania. Selected varieties were planted in anthracnose hotspot fields and the same CBVs were planted in a screen house to validate resistance to anthracnose. Anthracnose infection score, leaf length, leaf width, length of fifth internode, length of petiole, plant vigour, canopy height and canopy width were recorded. Data on number of plants emerging; days to flowering; days to maturity; plant stands at harvest; and grain yield were also collected and analysed using R software. Phenotypic traits evaluated differed significantly among genotypes, environment and genotype by environment interaction. Seventy-five percent of phenotypic traits evaluated were positively correlated to anthracnose resistance. Highly-strong correlations to anthracnose were observed on number of days to maturity, plant stands at harvest, plant vigour and grain yield. Leaf length, leaf width, length of fifth internode, length of petiole and number of stands emerging were strongly correlated to anthracnose resistance. Additive main effects and multiplicative interaction analysis (AMMI) revealed highest contribution of environment on anthracnose infection-58.9% and grain yield −84.9% compared to genotype effects on anthracnose infection −32.7% and grain yield-15.7%. Based on these results, four traits – plant vigour, number of days to maturity, number of plant stands at harvest and grain yield – are recommended for selecting anthracnose-resistant varieties. NUA 48, NUA 64 and RWR 2154 were superior varieties, resistant to anthracnose and high yielding, while Sweet Violet and VTT 923-23-10 were most stable varieties across environments. Further on-farm research is suggested to assess their performance and identify traits preferred by farmers.
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    Pathogenicity and Approaches for Management of Anthracnose in Common Bean (Phaseolus vulgaris) in Africa
    (INTERNATIONAL JOURNAL OF AGRICULTURE & BIOLOGY, 2022-10-16) Kadege, Edith; Venkataramana, Pavithravani; Assefa, Teshale; Ndunguru, Joseph; Mukankusi, Clare; Rubyogo, Jean; Mbega, Ernest
    Common bean plays significant role for human health globally and consumption of common bean is high in Africa as compared to other regions of the world. Despite common bean’s potential in Africa, productivity remains low due to diseases, drought and poor crop management. Anthracnose disease plays major role in reducing common bean grain yield in Africa. It is caused by seed-borne fungal pathogen Colletotrichum lindemuthianum leading to 100% yield loss. Limited and fragmented information on fungal infection, pathogenicity and management of common bean anthracnose in Africa affects decisions regarding anthracnose management. This review has been produced to collect information regarding anthracnose disease and its management in beans in Africa, which will be of great value to bean stakeholders. C. lindemuthianum can survive up to five years in infected seeds. During this time, seed is the main source of inoculum, infection and transmission of pathogen to new locations. Other sources and mechanisms of transmission include infected residues, farm tools, water, wind, and disturbance of moist foliage by animals, insects and people. Anthracnose is a hemibiotrophic pathogen, first establishing biotrophic interactions with common bean plant before switching to necrotrophism, causing significant yield loss. Mechanical force, chemical weapons, toxins and growth regulators facilitate pathogenesis. Use of anthracnose-resistant varieties is recommended to control common bean anthracnose followed by integrated anthracnose management. Future research in Africa should focus on why farmers rely heavily on local bean cultivars as seed and should use tricot as tool to screen anthracnose-resistant varieties and evaluate anthracnose management options for increased productivity, nutrition and income.