ISOENZYME GENE MARKER IN ASPARAGUS USED FOR IDENTIFICATION OF DOUBLED-HAPLOIDS AND HYBRIDS

Extracts from phylloclads of thirty populations and hybrids of asparagus were analyzed by starch gel electrophoresis for isoenzyme polymorphism. Six enzyme systems were examined: three of them, malate dehydrogenase (MDH), phosphoglucomutase (PGM) and shikimate dehydrogenase (SKD) showed inter- and intra-cultivar polymorphism as well as clear differences in the segregation of the hybrids studied.

SKD and MDH isoenzymes were used to identify haploids and doubled-haploids from anther culture in two genotypes heterozygous for both isoenzymes. Segregation of polymorphic loci was examined in 18 pairs of male and female crosses for MDH, PGM and SKD. We propose models which describe the Mendelian inheritance in the MDH, PGM and SKD.

Nine polymorphic bands in MDH, five in SKD, and nine in PGM were described. The Sartaguda population showed a specific band for PGM. Morado de Huetor (a population cultivated in local area) and Triguero, a wild asparagus, showed specific bands for SKD and PGM. Triguero lacked the fixed band of MDH always present in A. officinalis. Correlations were found between the band nearest the origin for PGM and the slow band for SKD. An association was found between two bands of MDH and female plants.