Abstract

Among the biological constraints facing maize production in Tanzania is a severe occurrence of maize lethal necrosis disease (MLN) raising an urgent need for application of new approaches. A pool of 22 maize genotypes with promising resistance and susceptibility to MLN infection were evaluated by Amplified fragment length polymorphism (AFLP) DNA fingerprinting analysis to detect genetic variation in the selected lines. Eleven AFLP primer combinations were screened and resulted in the identification of 95 polymorphic AFLP allelic fragments. Genetic similarities among the selected Tanzanian maize landraces and other maize lines were estimated by Unweighted Pair Group of Arithmetic Mean (UPGMA) and genotypes were clustered in three primary groups according to their reaction to MLN disease. Promising resistant and tolerant genotypes were grouped in cluster I and susceptible genotypes in clusters II and III. Landraces were grouped according to agro-ecological locations where they were collected. Unambiguous polymorphic AFLP fragments were eluted, purified and sequenced. Sequencing and nucleotide alignment on Basic Local Alignment Search Tool (BLAST) analysis showed similarities of fragments consistent with transcripts involved in disease resistance and stress responses. Further studies will explore the potential application of the identified AFLP markers and their significant association to MLN disease resistance genes in maize.

Key words: Zea mays, AFLP, maize lethal necrosis disease, Tanzania.