Selection of SSR Sets in Assignment to Dent and Flint Groups of Maize Inbred Lines Derived from European Hybrids

Abstract

Maize (Zea mays L.) breeders commonly assign inbred lines to groups in order to maintain the high level of hybrid vigor obtainable from crosses. It had already been reported that the genetic similarity estimated from 60 SSR loci was effective for the assignment of maize inbred lines derived from European hybrids, which contain mixtures of dent and flint germplasm, to dent or flint groups adapted to the cold regions of Japan. We evaluated a simplified assignment method using a smaller number of SSR loci. Two subsets were chosen from the full set of 60 SSR loci distributed uniformly throughout the maize genome. Set 1 composed of 25 loci and Set 2 composed of 14 loci were chosen based on the difference in allele frequency (0.4 for Set 1 and 0.5 for Set 2) between dent and flint groups. SSR loci of Set 1 and Set 2 carried a total of 176 and 99 alleles among 88 inbred lines, respectively. The numbers of alleles for Set 1 and Set 2 were 38% and 21% of the number of alleles for the full set of SSR loci, respectively. The assignments based on mean genetic similarity estimates using Set 1 SSR loci almost all corresponded to those using the full set of SSR loci. Furthermore, the assignments of several inbred lines based on Set 1 SSR loci were ascertained by testcross data. The results indicated that the assignment using Set 1 SSR loci with a similar accuracy to that of the full set of SSR loci is an efficient method in a maize breeding system.

DNA Profiling of Seed Parents and a Topcross Tester and its Application for Yield Improvement in Timothy (Phleum pratense L.)

“…The GD A estimates ranged from 0.653 to 0.756. The values were quite similar to those in maize reported by Enoki et al (2005), in which GD estimates between each miscellaneous maize inbred line and 35 dent inbred lines using 60 SSR markers carrying 463 alleles among 88 genotypes ranged from 0.65 to 0.80. In general, GD calculated by many DNA markers refl ects genetic diversity across the board genome.…”

“…Distant locations of these clones identified by SSR profiling also supported the potential for DNA profiling. As discussed in several studies on maize (Betran et al, 2003; Enoki et al, 2005), pairs with large GD led to their progenies' high yield through their high SCA caused from high heterozygosity, and the relationship between GD A estimates and the yield of the topcross progenies found in this study also seems to have come from the SCA between their seed and pollen parents. Clone c‐01, which is different from the other five, is much closer to Aurora (Fig.…”

“…Distant locations of these clones identifi ed by SSR profi ling also supported the potential for DNA profi ling. As discussed in several studies on maize (Betran et al, 2003;Enoki et al, 2005), pairs with large GD led to their progenies' high yield through their high SCA caused from high heterozygosity, and the relationship between GD A estimates and the yield of the topcross progenies found in Table 3. Analysis of molecular variance (AMOVA) for 16 genotypes of cultivar 'Aurora' and 51 genotypes from timothy breeding populations at the Kitami Agricultural Experiment Station (KAES) based on 28 simple sequence repeat (SSR) markers.…”

Use of molecular marker diversity to increase forage yield in timothy (Phleum pratense L.)

“…An average GD of the Syn strains in Exp. 1 based on the pairwise GD estimates within each strain, 'Kitakei 98301' and 'Kitakei 98303', and the significance of the averaged GD estimates was determined by t-test comparison (Enoki et al 2005). General genetic distance estimates of 40 parental clones of the polycross in Exp.…”

Analysis of European and North American Maize Inbred and Hybrid Lines by Monolithic and Perfusion Reversed-Phase High-Performance Chromatography and Multivariate Analysis

“…Different approaches are available to investigate the genetic diversity and relationships among maize lines (). These include morphological traits, pedigree data, molecular techniques based on the analysis of DNA ( − ), and biochemical traits such as isoenzymes ( − ) and zein storage proteins ( 1 , 2 , 8 ).…”