Identification of genetic distances and heterotic groups of inbred maize (Zea mays) lines using DNA fingerprinting

English: AFLP (Amplified Fragment Length Polymorphism) analysis has found widespread use in DNA fingerprinting because of its relative simplicity, low cost and high marker output. AFLP analysis also does not have the limitations associated with morphological characterisation and the use of other molecular markers such as RFLP's (Restriction Fragment Length Polymorphisms) and RAPD's (Random Amplified Polymorphic DNA markers). Furthermore, the AFLP technique has found widespread use in the identification of cultivars, varieties and breeding lines. The accurate identification of breeding material is extremely important, not only for the protection of breeder's rights, but also to accelerate plant-breeding programmes. The aim of this study was to use AFLP fingerprinting for the identification and genetic distance analysis of a collection of maize inbred lines from the Advanta Africa genebanks. Fifty maize inbred lines from Africa (local), Argentina, Zimbabwe (CIMMYT), Garst (USA) and Thailand were fingerprinted using AFLP's. A total of 107 scored AFLP loci were used to calculate pairwise genetic distances. This revealed an average genetic distance of 4.38% between all lines studied. The trend of the clustering pattern was more variation in the major clusters with less variation between lines in subgroups and even less variation within the minor groups. It was also further illustrated that the local and foreign inbred lines were not grouped separately. Neighbour joining cluster analysis of the genetic distance data yielded a dendogram that indicated the absence of relation between geographic diversity and genetic diversity. The resulting knowledge of genetic distance and identification of maize inbred lines in this study will contribute towards maize breeding programmes in Advanta Africa Seeds. It permits an organisation of germplasm resources and identification of parents for crossing blocks. This will enable the breeder to make more scientific based choices, where both additive and non-additive sources of genetic variation contribute to the gain. Our results have shown that AFLP technology is a rapid, informative and precise technique for identification of maize inbred lines in this study