Table 1.
Source and characterization of b alleles used in this study
| Allele | Source | Subspecies | Geographic location | Phenotype class* | Segregation analysis† | Clade‡ |
|---|---|---|---|---|---|---|
| B-bar | E.H. Coe, Jr.§ | Cultivated | North America | A | – | II |
| B-Bolivia | E.H. Coe, Jr. | Cultivated | Bolivia | B,C | – | I |
| B-I | E.H. Coe, Jr. | Cultivated | North America | D | – | III |
| B-Marker | E.H. Coe, Jr. | Cultivated | North America | A | – | I |
| B-Peru | E.H. Coe, Jr. | Cultivated | Peru | C,E | – | I |
| B-615 | Novartis CG00526 | Cultivated | North America | A | 36/38 | III |
| b-W23 | W23 inbred | Cultivated | North America | – | – | II |
| B-Gua31 | M. Goodman¶ | Cultivated | Guatemala | B | 10/10 | I |
| B-Mag466 | M. Goodman | Cultivated | Venezuela | A | 8/8 | I |
| B-Mex7a | M. Goodman | Cultivated | Mexico | A | 19/19 | III |
| B-Mex7b | M. Goodman | Cultivated | Mexico | F | 12/13 | III |
| B-M031 | J. Doebley∥ | huehuetenangenis | Guatemala | A | N.D. | |
| B-M033 | J. Doebley | huehuetenangensis | Guatemala | A | N.D. | |
| B-M075 | J. Doebley | mexicana | Mexico | A | 16/18 | I |
| B-M092 | J. Doebley | mexicana | Mexico | A | 34/35 | I |
| B-M046 | J. Doebley | parviglumis | Mexico | A | 51/51 | I |
| B-M063 | J. Doebley | parviglumis | Mexico | A | 18/20 | I, II** |
| B-M106 | J. Doebley | parviglumis | Mexico | A | 23/23 | III |
§ U.S. Department of Agriculture—Agricultural Research Service, Columbia, MO; ¶North Carolina State University, Raleigh, NC; ∥University of Wisconsin, Madison, WI; *Class A has weak pigmentation (see Fig. 2 A–C), B has strong pigment in some plant parts (Fig. 2 D, and E), C indicates seed pigmentation, D is strong in most plant parts (Fig. 2G), E is like class A but with much more tassel pigment (Fig. 2I), F is strong along margins of the sheath and around nodes (Fig. 2F).
† The numbers shown indicate the number of plants with a pigment phenotype/the total number of plants that were phenotypically wild type for both recessive markers that are linked to the b-tester allele. ND, not determined because of an inability to introgress these alleles. A 1/N-linkage had been previously determined by others. We observed a slightly higher level, 3.4% (8/235), of apparent double crossover events than expected (∼2%), probably because of occasional misscoring of markers.
‡The roman numerals indicate which clade each allele belongs to based on phylogenetic analysis.
**This accession segregated two b alleles; we reported the sequence of the allele in clade II. The clade I allele is very similar to the B-M046 allele.