Fertility restoring potential of rapeseed (Brassica napus) genotypes in Ogura and Polima CMS systems

Effective fertility restorer line is one of the essential components of hybrid seed production in rapeseed. The aim of this study was to evaluate the fertility restoring ability in a number of genotypes of rapeseed via test cross. Plant material carrying the fertility restorer gene (Rf) consisted of four lines (two Polima and two Ogura), seven rapeseed hybrids, 14 candidate promising fertile lines and 40 fertile plants selected from F2 populations of two rapeseed hybrids. Cytoplasmic male sterile (CMS) plant material consisted of three lines (two Polima and one Ogura) and sterile plants observed in F2 generation of a hybrid with Polima system. Crosses between fertile and male sterile genotypes were made. The progenies were planted in the field and number of fertile and sterile plants, pod density, shape andlength and number of seeds per pod were evaluated. Number of fertile to infertile plants ratio confirmed monogenic inheritance of fertility restoration and a strong relation between the male sterility system and Rf gene in parent. Genotypes carrying Rf gene had larger anthers, longer filament and bigger petals than sterile plants flowers. Based on homozygosity of fertility gene and the traits studied, promising genotypes of R'1.1, R'4.2 and R'2.1 were selected as effective restorer lines in Polima system.