the wild-type phenotype with solid purple petals, sepals, and labellum. All plants were grown in commercial orchid greenhouses until flowering. Flowering plants were then held in the laboratory for the duration of the study. The flower buds of P
Hongmei Ma, Margaret Pooler, and Robert Griesbach
Katrina G. Porter and Adelheid R. Kuehnle
advertisement solely to indicate this fact. 1 To whom reprint requests should be addressed. This research was funded by grants from the Gloeckner Foundation, the Dendrobium Orchid Growers' Association of Hawaii, and the Big Island Dendrobium Growers
Ernie DeMarie, Molly Weimer, and K.W. Mudge
Green pods of the C. reginae orchid were collected from a bog near Ithaca, NY. Pods were surface sterilized, and seeds were plated on agar media. The 8 germination treatments were arrange in a complete 3 way factorial consisting of 2 basal media (fish emulsion, FE vs. yeast extract, YE), 2 media pHs (4.8, 6.8), and 2 temperature regimes (constant 24 C vs. 6 wks. at 5 C prior to transfer to 24 C). Sequential stages of development included embryo enlargement and rupture of the testa (l), root elongation (2), leaf primordium development (3) and finally rhizoid development with or without protocorm greening (4). After 4 months post sowing, germination (stage 1 or beyond) was 56% and 0% on FE at pH 4.8 and 6.8 respectively, and 45% and 78% on YE at pH 4.8 and 6.8 respectively. Protocorm development from unchilled seeds after 4 months was greatest on YE at the lower pH, with 14% reaching stage 3 or 4, as contrasted to only 5% reaching stage 2 (none beyond), for the other germinated treatments. Chilled seeds had higher germination for all treatments but no development beyond stage 1 at 4 months post sowing.
Christine Yung-Ting Yen, Terri W. Starman, Yin-Tung Wang, and Genhua Niu
Dendrobium was reported to be the second most valued orchid genus in Japan in 2002 with a market share of 20%, only behind Phalaenopsis with a 30% market share ( Laws, 2004 ; Wang, 2004 ). Dendrobium has been the most economically
Mou Zong-min, Yan Ning, Li Shu-yun, and Hu Hong
plant physiological characteristics, e.g., high-quality flowers and vigorous seeds, which are valuable in horticulture and seedling production, respectively. For ornamental orchids, N fertilization can help growers produce orchids more efficiently. The
An experiment was initiated to determine the effect of a low N, high P and K fertilizer applied during the flowering season on a hybrid moth orchid (Phalaenopsis TAM Butterfly Blume.). On 1 Sept., plants of flowering size receiving N, P, and K at 100, 44, and 83 mg·L–1, respectively, from a 20N–8.8P–16.6K soluble fertilizer were given N, P, and K, at 30, 398, and 506 mg·L–1 (high P), respectively, at each or every fourth irrigation. Control plants continued to receive the 20N–8.8P–16.6K fertilizer. The high P treatments, regardless of the frequency of application, had no effect on the date of emergence of the flowering stem (spiking), anthesis, or flower size. All plants treated with the high P fertilizer had fewer flowers (15 to 19) than the controls (24 flowers). Continuous application of adequate N appears to be more important than low N and increased P for optimal flowering. In a separate experiment using the same hybrid orchid, terminating fertilization completely on 1 Sept., 29 Sept., or 27 Oct. or when the flowering stems were emerging (1 Oct.) reduced flower count (≤19 vs. 24). Flower longevity was reduced by 12 d when fertilization was terminated on 1 Sept. Flower size was unaffected by any treatment in either experiment. Discontinuing fertilization prior to late November reduced flower count. Withholding fertilization for extended periods resulted in red leaves, loss of the lower leaves, and limited production of new leaves.
Hongmei Ma, Margaret Pooler, and Robert Griesbach
P. schilleriana Rchb. were used in this study. All plants were grown in commercial orchid greenhouses until flowering. Flowering plants were then held in the laboratory for the duration of the study. Gene constructs. Promoters, structural
Ken W. Leonhardt
Erika Szendrák, Paul E. Read, Eszter R. Eszéki, Elizabeth Jámbor-Benczúi, and Aniko Csillag
Cultures of several orchid species [Barlia robertiana (Loisel.), Dactylorhiza fúchsii Soó, D. incarnata (L.) Soó, D. maculata (L.) Soó, D. majalis (Rchb.), D. saccifera (Brong) Soó, D. sambucina (L.) Soó, Gymnadenia conopsea (L.) R.Br., Himantoglossurn hircinum (L.) Spreng., Ophris sphegodes Mill., Orchis coriophora ssp. fragrans L., Orchis laxiflora ssp. palustris Lam., Orchis mascula L., Orchis morio L., Platanthera bifolia (L.) Rich., Spiranthes aestivalis (Poir.) Rich.] were initiated with fresh ripe seeds from desiccated fruit and 4-month-old in vitro seedlings. The medium used for both germination and seedling culture was a modified FAST medium. Samples for the scanning electron microscope (SEM) surveys were taken from the in vitro cultures and some plant materials were collected from their native habit. Samples were observed with a Tesla BS 300 SEM. Seeds ranged from 300 to 450 μm in length and were flask-shaped. The first germination step is opening of the seedcoat, when the first few white cells will be visible. After a few weeks, the apical meristem appears. The young protocorm is covered with numerous translucent rhizoids. In the last stage of germination, the first root and the first true leaf start to develop. After 2 years, they are suitable for transfer ex vitro. Structure of the mature organs and tissues can be examined at this stage.