Applicability of Biochemical and Genetic Markers in the Polymorphism Analysis of Maize Lines

The guidelines elaborated by the Community Plant Variety Office (CPVO) of the European Union for the registration and patenting of varieties and hybrids of cultivated crops are based on the triple criteria of distinctiveness, uniformity and stability (DUS). For many species, however, morphological descriptions are not sufficient for the detection of differences between varieties. Techniques that allow varieties to be identified and distinguished precisely and reliably are essential not only for variety identification, but also to protect variety ownership rights. Biochemical and molecular genetic methods have now reached a level of development that makes them suitable for this purpose, and when these are combined with conventional field observations the breeding stock can be unequivocally identified and any existing genetic diversity can be detected. The regular application of such analyses is a fundamental criterion in the case of maize, as more and more closely related hybrids are being entered for testing. The aim of the present work was to examine how isoenzyme patterns and PCR-based genetic markers could be used in polymorphism analysis, in order to obtain information on the genetic diversity of Hungarian breeding materials. The emphasis was on finding genetic markers characteristic of individual maize varieties, rather than of maize as a species.