Table 1.
Percentage of chromosome associations at diakinesis in the genitors and hybrids scored among 20 meiocytes per genotype.
Fig 1.
Meiocytes in the U. humidicola hybrids (2n = 36) exhibiting multiple-chromosome associations at prophase I.
a) Meiocyte in pachytene exhibiting a tetravalent (blue arrow). b) Meiocyte in diplotene exhibiting a tetravalent (blue arrow). c, d) Meiocytes in diakinesis exhibiting tetra- and hexavalents (blue and red arrows, respectively) with bivalents already in separation.
Table 2.
Percentage of meiotic abnormalities in the genitors and hybrids of Urochloa humidicola, based on [44].
Fig 2.
Meiocyte in pachytene exhibiting two nucleoli of different sizes.
Meiocyte in pachytene exhibiting two nucleoli of different sizes. The arrow indicates the smaller nucleolus.
Fig 3.
Meiocyte in pachytene exhibiting small chromosomes.
a) Meiocyte in pachytene exhibiting several small chromosomes (arrows). b) Meiocyte in diakinesis exhibiting six small bivalents (arrows). c) Metaphase I with the six small bivalents allocated peripherally in the plate (arrow). d) Metaphase I with the six small bivalents separated in the metaphase plate. The arrow indicates the set of six small bivalents.
Table 3.
Summary of the SSR loci used in the genetic linkage map construction.
Fig 4.
A genetic linkage map for the hexaploid U. humidicola based on single-dose markers.
Table 4.
Linkages in repulsion identified in the LGs and its correspondent LOD score, in bold text.
The linkage phase diagram of each band in both genitors of the mapping population are also shown. The configuration ao x ao indicates a type C band, ao x oo indicates a type D1 band, and oo x ao indicates a type D2 band.
Fig 5.
Suggested origin of U. humidicola.
Illustrative scheme of the origin of the hexaploid Urochloa humidicola, based on cytogenetic and molecular data. The two different genomes are indicated as A and B. The figures represent the amplification profiles of two microsatellite loci (I. BhUNICAMP010 and II. BhUNICAMP037) and the corresponding amplification regions of genomes A and B.
Fig 6.
Meiotic behavior in the U. humidicola hybrids.
Meiotic behavior evaluated in the hybrids (2n = 36) listed in Tables 1 and 2. a) Meiocyte in anaphase I exhibiting 12 segregated chromosomes of genome B and six small bivalents of genome A, with late disjunction, in metaphase I (arrow). b) Anaphase I with the laggard chromosomes of genome A (arrows). c, d) Metaphase II (genome B) with six scattered chromosomes of genome A (arrows). e) Late anaphase II with genome A in the metaphase plate (arrow). f) Tetrad with small micronuclei in two microspores (arrows).