Spigelia marilandica, an herbaceous perennial native to the temperate eastern United States, has great potential for the sunny garden due to a fairly long flowering period-and long (3.5-5.5 cm) tubular corollas that are scarlet on the outside and yellowish within. Non-wild collected seeds were disinfested using conventional procedures, and after 8 wk at 4°C, four seeds germinated in vitro. Preliminary experiments examined seedling lines (# 1, 2, 5 and 6) and media (MS versus DKW.) Line 6 was found to be consistently more proliferative over a six month period. Trend analysis demonstrated no difference in total number of axillary shoots produced on full versus 1/2 MS media. MS-derived microcuttings were chlorotic but appeared to root better than DKW-derived microcuttings.
Serge Gudin and Laurence Aréne
Flowers of two cultivars of Rosa hybrida were treated or not with putrescine before being pollinated from 2 to 8 days after anther emasculation. On both cultivars the 10-3 M putrescine treatment extended the effective pollination period, as shown by the best hip formation rates and mean number of seeds per hip. On one cultivar, the 10-5 M putrescine treatment increased fertilization efficiency (more hips obtained). The effect of putrescine was proportionally more important on the cultivar characterized by the highest stigmatic exudate pH. Putrescine also influenced in vitro pollen germination by increasing the length of emitted pollen tubes (10-3 and 10-5 M-putrescine) and the quantity of germinated pollen grains (10-5 M putrescine).
Qi Zhang, Sheng Wang, and Kevin Rue
, alkaligrass ( Puccinellia spp.), a native of the prairies in the western United States and Canada, is highly recommended for home lawns under high saline stress. Harivandi et al. (1982) reported that 48% of Puccinellia spp. seeds germinated after a 15-d
Michael Stein, Corina Serban, and Per McCord
Seed dormancy, specifically endodormancy, is a strong inhibitor of rapid germination in stone fruit seeds, including those of sweet cherry ( Prunus avium ). Endodormancy has been suggested to be a crucial process in seeds because it prevents
YanLing Zheng, GaoJuan Zhao, and HuanCheng Ma
. Optimum moisture contents for pea seeds stored at different temperatures Ann. Bot. (Lond.) 74 531 540 Yamazaki, J. Miyoshi, K. 2006 In vitro asymbiotic germination of immature seed and formation of protocorm by Cephalanthera falcata (Orchidaceae) Ann
Sherry Kitto and Jeanne Frett
Hexastylis shuttleworthii is a highly ornamental shade-tolerant evergreen herbaceous plant native to the southeastern U.S. that is difficult to propagate using traditional methods. Micropropagation would make possible the wider distribution of selected clones. Seeds were surface-sterilized and germinated in vitro. Seedling clones were maintained on a MS basal medium containing 1 mg/L BA and were subcultured monthly. Proliferation of clones 2 and 3, maintained on media supplemented with 1, 2.5 or 5 mg/L BA for 6 months, increased slightly with increasing BA concentration; however, proliferation decreased slightly over the experimental period. Rooting medium (perlite, vermiculite, MetroMix 510, Bacto Growers Mix) did not effect microcutting root production or subsequent plant survival. Microcuttings rooted in vitro (67% survival) generated more leaves compared to microcuttings rooted under humidity domes with mist in the greenhouse (8% survival). After rooting in vitro, multiple-shoot clumps (95%) survived better than individual shoots (29%) under greenhouse conditions. Plants were easily established when planted in raised beds in a lath house.
Chad E. Finn, James J. Luby, Carl J. Rosen, and Peter D. Ascher
was supported, in part, by the U.S. Dept. of Agriculture under Specific Cooperative Agreement no. 58-32U4-7-047. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must
X. Wang, J.T.A. Proctor, S. Krishna Raj, and P.K. Saxena
Ginseng is a very valuable agricultural species grown for its root, which contains pharmacologically active constituents. One limiting factor for expansion of ginseng production is an efficient method for mass propagation. Currently, seeding is the principal method of propagating ginseng, but the embryo of ginseng seeds at harvest is immature. A stratification schedule consisting of a cool-warm-cool temperature treatment over 18-22 months is required for embryo development and seed germination. An alternative for the efficient production of ginseng is mass propagation through the use of in vitro culture techniques. The objective of this work was to develop a highly efficient system for regeneration of ginseng. The efficacy of three auxins, viz. 2,4-D, NAA and dicamba, were compared for the induction of somatic embryogenesis in American ginseng. Somatic embryos formed on ginseng cotyledonary, zygotic embryo, and shoot explants after 8 weeks of induction by the auxins. Significantly more somatic embryos were induced by culture of any of the ginseng explants on media supplemented with 5 μmol·L-1 2,4-D than any other auxin treatment. Histological and SEM studies confirmed that the regenerants were somatic embryos. Somatic embryos germinated and developed into normal plants in 3-6 months. The development of a regeneration system for ginseng using somatic embryogenesis is a necessary first step for mass propagation and the improvement of American ginseng.
Jules Janick, Christiane Cabral Velho, and Anna Whipkey
Journal Paper no. 12,525 of the Purdue Univ. Agricultural Experiment Station. We thank William Carlson, Southern Forestry Res. Dept., Weyerhaeuser Corp., for providing seed. The cost of publishing this paper was defrayed in part by the payment of
Matteo Serena, Bernd Leinauer, Rossana Sallenave, Marco Schiavon, and Bernd Maier
step in the process of screening for salinity tolerance in any plant species is to conduct a germination test. According to protocols outlined by the Association of Official Seed Analysts ( AOSA, 2009 ), media considered acceptable for use in standard