TY - JOUR
T1 - A synthetic hexaploid (2n = 42) oat from the cross of Avena strigosa (2n = 14) and domesticated A. magna (2n = 28)
AU - Ladizinsky, Gideon
PY - 2000
Y1 - 2000
N2 - A synthetic hexaploid oat was produced by chromosome doubling of a sterile triploid hybrid between cultivated Avena strigosa (2n = 14) cv. Saia and a domesticated form of A. magna (2n = 28). The synthetic hexaploid was intermediate between its parents in panicle shape and lemma color, similar to the tetraploid parent in spikelet structure, and to the diploid parent in having a single, albeit partially shriveled seed per spikelet, and low protein content. By the third generation, plants with yellowish lemmas, mostly two seeds per spikelet and better filled grains had been selected. Rust resistance of the diploid parent was retained in the synthetic hexaploid, but not tolerance to barley yellow dwarf virus disease (BYDV). Chromosome associations at meiosis in the triploid hybrid was low, with over 60% of them being univalents. Bivalent association was the rule in the synthetic hexaploid with an occasional one or two quadrivalents. Regular meiosis with 21 bivalents was observed in further generations. The preferential pairing of homologous chromosomes in the synthetic hexaploid was probably contributed by the A. strigosa genome which exhibits this tendency in artificial allopolyploid situations. Selection of yellow lemma color and two seeds per spikelet suggests that the genes controlling these traits are located on the chromosomes involved in quadrivalents in the synthetic hexaploid. The potential and limitations of utilizing the synthetic hexaploid in oat research and breeding are briefly discussed.
AB - A synthetic hexaploid oat was produced by chromosome doubling of a sterile triploid hybrid between cultivated Avena strigosa (2n = 14) cv. Saia and a domesticated form of A. magna (2n = 28). The synthetic hexaploid was intermediate between its parents in panicle shape and lemma color, similar to the tetraploid parent in spikelet structure, and to the diploid parent in having a single, albeit partially shriveled seed per spikelet, and low protein content. By the third generation, plants with yellowish lemmas, mostly two seeds per spikelet and better filled grains had been selected. Rust resistance of the diploid parent was retained in the synthetic hexaploid, but not tolerance to barley yellow dwarf virus disease (BYDV). Chromosome associations at meiosis in the triploid hybrid was low, with over 60% of them being univalents. Bivalent association was the rule in the synthetic hexaploid with an occasional one or two quadrivalents. Regular meiosis with 21 bivalents was observed in further generations. The preferential pairing of homologous chromosomes in the synthetic hexaploid was probably contributed by the A. strigosa genome which exhibits this tendency in artificial allopolyploid situations. Selection of yellow lemma color and two seeds per spikelet suggests that the genes controlling these traits are located on the chromosomes involved in quadrivalents in the synthetic hexaploid. The potential and limitations of utilizing the synthetic hexaploid in oat research and breeding are briefly discussed.
KW - Avena
KW - Chromosome doubling
KW - Interspecific hybridization
KW - Preferential pairing
UR - http://www.scopus.com/inward/record.url?scp=0033710628&partnerID=8YFLogxK
U2 - 10.1023/A:1004056315278
DO - 10.1023/A:1004056315278
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AN - SCOPUS:0033710628
SN - 0014-2336
VL - 116
SP - 231
EP - 235
JO - Euphytica
JF - Euphytica
IS - 3
ER -