Present address and address for reprint requests: Department of Forestry, Fisheries and Wildlife, University of Nebraska, Lincoln, Nebraska 68583–0814.
INTERGENERIC HYBRIDIZATION AMONG FIVE GENERA OF THE FAMILY LESSONIACEAE (PHAEOPHYCEAE) AND EVIDENCE FOR POLYPLOIDY IN A FERTILE PELAGOPHYCUS×MACROCYSTIS HYBRID
Article first published online: 28 JUN 2008
Journal of Phycology
Volume 31, Issue 6, pages 1012–1017, December 1995
How to Cite
Lewis, R. J. and Neushul, M. (1995), INTERGENERIC HYBRIDIZATION AMONG FIVE GENERA OF THE FAMILY LESSONIACEAE (PHAEOPHYCEAE) AND EVIDENCE FOR POLYPLOIDY IN A FERTILE PELAGOPHYCUS×MACROCYSTIS HYBRID. Journal of Phycology, 31: 1012–1017. doi: 10.1111/j.0022-3646.1995.01012.x
- Issue published online: 28 JUN 2008
- Article first published online: 28 JUN 2008
- Received 21 April 1995. Accepted 24 August 1995.
- Dictyoneuropsis reticulata;
- Dictyoneurum californicum;
- intergeneric hybridization;
- Macrocystis angustifolia;
- Macrocystis integrifolia;
- Macrocystis pyrifera;
- Nereocystis luetkeana;
- Pelagophycus porra;
Hybridization was attempted by combining gametophytes between intergeneric pairs among the following taxa in the Lessoniaceae: Macrocystis pyrifera (L.) C. Agardh, M. integrifolia Bory, M. angustifolia Bory, Pelagophycus porra (Leman) Setch., Nereocystis luetkeana (Mert.) Post & Rupr., Dictyoneurum californicum Rupr., and Dictyoneuropsis reticulata (Saud.) Smith. Hybrid sporophytes were produced in some combinations involving Macrocystis × Pelagophycus and Macrocystis × Dictyoneurum, and in all combinations of Dictyoneuropsis × Dictyoneurum. This is the first report of intergeneric hybrids involving Dictyoneurum. Gametophytes of P. porra had 16–24 chromosomes. Gametophytes from a fertile Macrocystis-Pelagophycus hybrid were crossed with Macrocystis and Pelagophycus gametophytes. Hybrid male gametophytes and Pelagophycus female gametophytes produced sporophyte progeny, but hybrid males with Macrocystis females did not. A single hybrid female gametophyte did not produce gametophytes in combination with hybrid males, Pelagophycus males or Macrocystis males. The hybrid gametophytes had approximately 30 chromosomes. It is hypothesized that the hybrid is an alloploid, containing a complete set of Macrocystis and Pelagophycus chromosomes, which may have allowed meiosis and sporogenesis to proceed normally in the hybrid sporophyte found in the sea. Thus, reproductive isolating mechanisms appear to operate at both pre- and postzygotic stages, and both can be overcome in intergeneric hybrids.