Mycorrhizal colonization of major banana genotypes in six East African environments

In the densely populated East African highlands (EAH), banana is a major staple food. In the last decade, serious yield declines were observed caused by soil fertility depletion and increased pressure of pests and diseases. Arbuscular mycorrhizal (AM) fungi form symbiosis with plant roots improving nutrients and water absorption, and protecting plants against a number of biotic (e.g. root pathogens) and abiotic (e.g. drought) stresses. Use of crop genetic diversity could be an appropriate option to improve production by using highly mycotrophic genotypes. This study assessed AM fungal root colonization of 18 banana genotypes across 6 locations in East Africa (Rwanda, Burundi, Kenya, DR Congo, Uganda and Tanzania). Soil and root sampling was carried out on each genotype. Data were collected on root colonization frequency and intensity, soil pH, cation exchange capacity and mineral nutrients. The results suggested that (i) high receptivity but low banana genotype specificity to the AM fungi exist among the five genotypes present in all the study sites; (ii) high variability in root colonization exists within the site among a wide range of Musa genotypes: from AA, AAA to AAB, ABB and tetraploids.