Evaluation of Restoration Patterns (Rf) of Male Sterile Cytoplasm (cms) of some Early Maize Local Populations from Transylvania-Romania

Romania is one of the great maize cultivating countries in Europe. The yearly maize cultivated areas are around 3 million hectares worldwide. The great number of farmers, the climate and land differences, as well as the germplasm sources from Turkey and Italy, in the XVIIth and XVIIIth centuries, as well as those which came directly from America in the early XXth century, caused the differentiation of a great number of local populations, with a vegetation period from FAO 180 to FAO 700, from indurata to dentiformis convariety. In our maize breeding programs the local maize landraces shows a particular interest, especially as useful sources for adapting capacities, physiological (cold resistance, precocity), agronomic and valuable quality traits. The aim of this investigation consisted in detecting the presence of dominant alleles of Rf (fertility restauration) genes in more than 50 local landraces provided from the germplasm collection of the Maize Breeding Laboratory, at the Agricultural Research and Development Station, Turda. They were crossed with different types of cytoplasmic male sterility: cms-C, cms-ES, cms-M and cms-T and the observations of pollen restoration reactions were scored, in 2015.The fertility restoration data clearly showed the relationship between the two representative “C” and “ES” of the group-C. 20.8% of the landraces maintained the male sterility induced by cms-C and 13.2% to cms-ES. Many genotypes were imperfectly sterile or fertile, respectively proved to be different type of restorers: 79.2% to cms-C, 73.6% to cms-ES, 66.0% to cms-T and 58.5% cms-M. A special remark should be made concerning Zagra local population, which maintains all three types of cytoplasmic male sterility and Răzoare population that maintains almost entirely the pollen male sterility for the three types of cytoplasm. Câmpeni population fully maintains male sterility for cms-C and cms-M and fully restores cms-T. Generally, the pollen fertility restoration reaction of the local landraces was in connection with cms-source, cms-versions, of several landrace backgrounds, nuclear x cytoplasmic interaction and environmental conditions.