РЕАКЦИЯ НОВЫХ САМООПЫЛЕННЫХ ЛИНИЙ КУКУРУЗЫ НА ПАРАГВАЙСКИЙ ТИП ЦМС

Abstract

It is extremely important to study cytoplasmic male sterility (CMS) in maize since it is impossible to conduct large-scale commercial seed production of hybridized maize without CMS. The purpose of the current study was to identify the response of the new self-pollinated maize lines in a sterile cytoplasm of the Paraguay type, to group the lines according to the composition of fertility restoring genes based on an optimal quantity of the analyzed crossings. The field trials were carried out in 2016–2019 in the State Scientific Establishment “Agricultural research center “Donskoy”” (SSE “ARC “Donskoy”). To obtain hybrid combinations, the method of full top-crosses, namely eight testers and ten lines, was used. The new early-ripening and mid-ripening self-pollinated maize lines (I6), developed in the ARC “Donskoy”, were grouped according to the composition of the alleles of fertility restoring genes of the Paraguay (“C”) type of CMS based on the flowering pattern of the test cross F1 hybrids. The first group included the line SP 207 (genotype rf4rf4 rf5rf5 rf6rf6); the second group included the line SP 209 (genotype rf4rf4 rf5rf5 Rf6Rf6); the third group included the line SP 194 (genotype rf4rf4 Rf5Rf5 rf6rf6); the fourth group included the line SP 198 (genotype Rf4Rf4 rf5rf5 rf6rf6); the fifth group included the lines SP 203 and SP 195 (genotype rf4rf4 Rf5Rf5 Rf6Rf6); the sixth group included the line SP 206 (genotype Rf4Rf4 rf5rf5 Rf6Rf6); the seventh group included the line SP 180 (genotype Rf4Rf4 Rf5Rf5 rf6rf6); the eighth group included the lines SP 210 and SP 197 (genotype Rf4Rf4 Rf5Rf5 Rf6Rf6). The lines SP 207, SP 210 and SP 197 were of the greatest practical value when converting maize hybrids to a sterile base: the line SP 207 was a complete sterility fixer; the lines SP 210 and SP 197 were constant natural fertility restorers. In order to optimize the quantity of the analyzed crossings for grouping the maize lines according to the composition of the alleles of fertility restoring genes of the Paraguay (“C”) type of CMS, it was necessary to use such sterile sources as KR 21C (group IV), WF9C (group V), LC (group VI), W401C (group VII). The minimum quantity of analyzers to determine the response of the lines on the Paraguay type of CMS should be at least two. However, it was necessary to use sterile sources of certain classes, such as KR 21C (group IV) and Gb834 C (group I).