Genetic control of B chromosome transmission rate in Zea mays ssp. mays (Poaceae)
We selected genotypes of high and low B chromosome transmission rate (TR) in a native race of maize (Pisingallo) from northwest Argentina. We made 20 female 0B x male 1B and 20 f.1B x m.0B crosses. The former (G0m) showed a large variation of B TR, with a mean of TR ± SE = 0.52 ± 0.06, ranging from...
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| Autores principales: | , , , , |
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| Formato: | JOUR |
| Materias: | |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00029122_v83_n9_p1107_Rosato |
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| Sumario: | We selected genotypes of high and low B chromosome transmission rate (TR) in a native race of maize (Pisingallo) from northwest Argentina. We made 20 female 0B x male 1B and 20 f.1B x m.0B crosses. The former (G0m) showed a large variation of B TR, with a mean of TR ± SE = 0.52 ± 0.06, ranging from 0.17 to 0.98. In the latter (G0f) the mean was TR = 0.47 ± 0.02 ranging from 0.31 to 0.58. Plants showing the highest and the lowest TR were selected to constitute the progenitors of the G1 generations. We made 19 f.0B x m.2B crosses, studying 24-30 plants per cross. The TR of the high (H) and low (L) lines in G1m (G1mH and G1mL) significantly differed (TRH = 0.65 ± 0.03, TRL = 0.40 ± 0.01), indicating that the H and L lines are different groups. The large variation in male TR suggests that preferential fertilization of gametes carrying B chromosomes does not always occur. We also selected plants showing high and low TR in the progenies of f.1B x m.0B crosses (G0f), and made 24 f.1B x m.0B crosses, studying 23-30 plants per cross. The TRs of the H and L lines in G1f (G1fH and G1fL) were significantly different (TRH = 0.48 ± 0.025, TRL = 0.40 ± 0.02). The TRs in G0f and G1fL were significantly different (TR = 0.47 ± 0.02 and 0.40 ± 0.02, respectively), while this was not the case between G0f and G1fH. Our results demonstrate the existence of genotypes controlling B TR in this native population of maize. |
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