Search Results

You are looking at 51 - 60 of 88 items for :

  • "ornamental plant breeding" x
  • Refine by Access: All x
Clear All
Free access

Gabriela Verdugo Ramírez, Mauricio Cisternas Baez, Ursula Steinfort, Hermine Vogel, and Rosa Cueto-Ewoldt

Free access

Clara E. Trueblood, Thomas G. Ranney, Nathan P. Lynch, Joseph C. Neal, and Richard T. Olsen

Although Hypericum androsaemum L. is a valuable landscape plant, the species can be weedy and potentially invasive in certain locations. Infertile, non-invasive cultivars of H. androsaemum with desirable ornamental features would be ecologically beneficial and valuable for the horticultural industry. The male and female fertility of 10 triploid H. androsaemum, developed with a combination of variegation and foliage colors, was investigated under greenhouse (controlled pollination) and field conditions (natural pollination). Male fertility was evaluated based on pollen viability tests (pollen staining and pollen germination). Female fertility was based on fruit set, seed set, germinative capacity of seeds, and number of seedlings produced for each flower. Although values for different measures of fertility varied among triploid clones, pollen germination was significantly reduced for all triploids and nine of the 10 triploids produced no viable seed. These results represent 100% failure of ≈171,000 potential fertilization events based on fertility levels of diploid controls. The remaining triploid clone produced two seedlings per flower compared with 260 seedlings per flower for the controls. However, the seedlings produced by the triploid clone died shortly after germination. This research documented that the triploid H. androsaemum tested are highly infertile with no measurable female fertility. These clones will provide ideal alternatives to fertile forms of H. androsaemum where invasiveness is a concern. These methods also provide a useful protocol for evaluating fertility of other taxa that are selected or developed as non-invasive cultivars of potentially weedy species.

Free access

Loren C. Stephens

Progenies derived from self-pollination and parent–offspring backcrosses of Echinacea purpurea (L.) Moench accession PI 631307 revealed that a sporophytic self-incompatibility (SI) system was operating in this germplasm. Offspring of progenies from the original accession were self-incompatible, but most self-pollinations resulted in some self-seed set. One seedling from such a self-pollination was reciprocally crosscompatible with its parent, proving that a sporophytic SI system was operational. The F3BC1 progeny could be classified into two offspring groups. The first group of two seedlings was reciprocally compatible with its seed parent but reciprocally incompatible with its pollen parent based on stigma collapse of the seed parent florets 2 to 4 days after pollination. The second offspring group of three seedlings was reciprocally incompatible with its seed parent but reciprocally compatible with its pollen parent. Seed set data were in agreement with classification by stigma collapse in seven of 10 backcrosses, including in several reciprocally compatible backcrosses that provided further proof of a sporophytic SI system. Additionally, a χ2 test showed that the data fit a sporophytic SI model with S allele dominance operating in pollen and pistil. Assuming that S allele dominance is widespread within Echinacea purpurea, it should be possible to produce inbred lines by making successive generations of full-sib crosses.

Free access

Daniel F. Warnock

Oral Session 6—Ornamental Plant Breeding Moderator: Daniel F. Warnock 18 July 2005, 4:00–6:00 p.m. Room 107

Free access

Marietta Loehrlein and Sandy Siqueira

Oral Session 6—Ornamental Plant Breeding Moderator: Daniel F. Warnock 18 July 2005, 4:00–6:00 p.m. Room 107

Free access

Jessica Gaus, Dennis Werner, and Shyamalrau Tallury

Oral Session 6—Ornamental Plant Breeding Moderator: Daniel F. Warnock 18 July 2005, 4:00–6:00 p.m. Room 107

Free access

Leslie A. Blischak and Richard E. Veilleux

Oral Session 6—Ornamental Plant Breeding Moderator: Daniel F. Warnock 18 July 2005, 4:00–6:00 p.m. Room 107

Free access

Michael Compton

Oral Session 6—Ornamental Plant Breeding Moderator: Daniel F. Warnock 18 July 2005, 4:00–6:00 p.m. Room 107

Free access

David Shupert, David H. Byrne, and H. Brent Pemberton

Oral Session 6—Ornamental Plant Breeding Moderator: Daniel F. Warnock 18 July 2005, 4:00–6:00 p.m. Room 107