GENETIC-ANALYSIS AND NOMENCLATURE FOR 7 ISOZYME SYSTEMS IN BRASSICA-NIGRA, BRASSICA-OLERACEA AND BRASSICA-CAMPESTRIS

General criteria for the assignment of names to enzyme systems, region s of activity, isozyme loci and allozymes have been lacking in crucife r species. This paper proposes a standard nomenclature for seven isozy me systems in the three diploid species of U's triangle: Brassica nigr a, B. oleracea and B. campestris. Gel/electrode buffers, which provide d the best resolution for seven isozyme systems, acid phosphatase (APS ), aconitase (AGO), leucine aminopeptidase (LAP), 6-phosphogluconate d ehydrogenase (6 PGD), phosphoglucoisomerase (PGI), phosphoglucomutase (PGM), and triosephosphate isomerase (TPI), were proposed as standards . Isozyme genetic analysis was determined for B. oleracea and B. campe stris from previous studies and by segregation of selfed progenies of heterozygous B. nigra plants. Several populations were studied and 148 allozymes at the 18 loci observed were described for the three specie s. Their relative mobility was studied using a pure line of oilseed ra pe as reference. The comparison of the different alleles within and be tween the species is discussed.