Fingerprinting and genetic diversity laboratory protocols have been optimized for high-throughput analysis of maize. Eighty-five SSR markers have been chosen that span the entire genome and can be multiplexed (4-12 SSRs per lane) on an automatic DNA sequencer. Maize populations can also be fingerprinted in a very efficient method by bulking 15 individuals from the same population; this bulk is amplified and run together on the sequencer. This allows the use of peak area from the sequencer output to estimate allele frequencies from each population. Two bulks per population are fingerprinted to have a total of 30 individuals per population in the estimation. Only a limited structure can be deduced in the inbred lines by using molecular markers, reflecting the breeding strategy at CIMMYT of mixing many germplasm pools to increase diversity in tropical and subtropical breeding lines. Origin, and to a lesser extent heterotic groupings, of the populations are reflected in the SSR diversity measurements.

English

0409|AGRIS 0401|AL-Maize Program

Juan Carlos Mendieta

CIMMYT Staff Publications Collection