Author
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COUSINS, PETER |
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Submitted to: Acta Horticulturae
Publication Type: Proceedings Publication Acceptance Date: 7/23/2010 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Grapevine seedlings initially display spiral phyllotaxy of true leaves, then undergo a shift to alternate phyllotaxy with the production of the first lateral meristems (typically tendrils). The node at which the shift from spiral to alternate phyllotaxy occurs varies from about the 4th to about the 10th node on the vine. To investigate the genetic control of the transition from spiral phyllotaxy to alternate phyllotaxy, a population segregating for this trait was developed and screened. The population derived from four female parents and six male parents crossed in a Design 2 mating array (all female parents crossed to all male parents). The female parents were the pistillate flowered rootstock varieties 1613 Couderc, 93-5 Couderc (California clone), Vitis rupestris 187G, and Fercal. The male parents were grape rootstock germplasm and selections with diverse species backgrounds, including V. mustangensis, V. riparia, V. tiliifolia, and V. rupestris. Seedlings from controlled crosses were grown in individual pots in a greenhouse and the node number of the first observed lateral meristem was recorded; the goal was 50 seedlings per population for each of 24 populations, although some populations showed poor seed germination. The transition from spiral to alternate phyllotaxy does not appear to be under simple genetic control, but there is significant variation from family to family in this trait. |
