LINKAGE RELATIONSHIPS OF GENES FOR LEAF MORPHOLOGY AND DOUBLE FLOWERING IN MATTHIOLA-INCANA

The inheritance and linkage relationships of a leaf morphology gene of Matthiola incana were investigated. The allele for sinuate leaf shape , c, was found to be recessive to the allele for normal entire leaf, C . The c allele was tightly linked to the recessive allele for double f lowering, s. The recombination frequency between the two loci was clos e to zero. The mode of inheritance of the C gene was in accordance wit h the hypothesis that a pollen lethal gene is responsible for the cons tant 1:1 segregation ratio of double-flowered (= male sterile) to sing le-flowered (= fertile) plants in most M. incana breeding lines. The s inuate leaf allele seemed to reduce the frequency and delay the flower ing of double-flowered plants. The importance of the C gene as a doubl e flowering marker in the cultivation and the breeding of M. incana is discussed.