Virulence and Diversity of Fusarium oxysporum f.sp. cubense Infecting Bananas in Tharaka Nithi County, Kenya
Malaka Musime1, Mwongera Thuranira2, Maina Mwangi1, Nchore Shem1, Lubabali Hudson2, Gathambiri Charity2
1Kenyatta University, School of Agriculture and Enterprise Development, Kenya
Banana belongs to Musaceae family and is cultivated worldwide supporting the livelihoods of many people and the economies of many countries. One of the diseases that is significantly reducing banana yield in Kenya is the Panama disease caused by Fusarium oxysporum f.sp. cubense (Foc). This experiment was carried out in Tharaka Nithi County in Kenya to assess the pathogenicity of Foc isolated from Gros Michel banana varieties, Cavendish banana varieties and from plantains. Laboratory work and greenhouse experiments were done at the Horticulture Research Institute (HRI) in Kandara, Kenya. Conidia were harvested from 14 days old cultures on PDA media. The spore suspension was adjusted to 10-6 spores/ml by counting using a hemocytometer slide. To inoculate the plants, the soil was removed gently from the 2-month-old tissue cultured banana seedlings to expose the roots. The banana roots were wounded and immersed in Foc spore suspension for 30 minutes while shaking before planting into the sterile compost soil. A control was immersed in sterile water. All isolates were tested in four replicates of one plant per isolate. Disease severity was recorded every week for a period of 16 weeks following the disease scale of 1-5. For external symptoms, 1 indicated no symptom/healthy, 2 indicated initial yellowing mainly on the lower leaves, 3 indicated yellowing of all the lower leaves including some discolouration on the younger leaves, 4 indicated intense yellowing on all leaves while 5 indicated plant dead/complete wilting. Data was analysed using one way ANOVA. The isolates that revealed a scale of 3 included AP005 and AP003. Those that revealed a scale of 2 included AP001, AP002, AP004,AP006, AP007, AP008, AP009, AP010,AP011, AP012, CV001,CV002, CV004,CV005, CV006, KL001,KL003, KL004,EM001,UK001, FH001, and GN001. The results indicated that some of the Foc isolates used in the experiment were pathogenic. This therefore indicates that Foc is one of the diseases affecting bananas in Tharaka Nithi County in Kenya. The management strategies are therefore necessary for the control of Foc pathogen in Kenya. There is still a laboratory and greenhouse ongoing experiment for this work.
Keywords: Cavendish, Fusarium oxysporium, Gros Michel, Panama disease, pathogenicity
Contact Address: Malaka Musime, Kenyatta University, School of Agriculture and Enterprise Development, Box 4, 00232 Ruiru, Kenya, e-mail: samuelmalaka540gmail.com