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A broad source of Gerbera × hybrida Hort. germplasm was evaluated for vase life. Senescence mode, i.e., bending or folding of stems or wilting of ligulae was also recorded for flowers evaluated. Intensive selection was practiced to improve vase life. About 10% of the plants from a sample population were selected for having flowers with high vase life. Progeny means for vase life resulting from a topcross between these plants and `Appleblossom' were used to select five plants (about 1.5% of the sample population) whose flowers had high vase life. A diallel cross using these five plants as parents resulted in a progeny population with an increase in mean vase life of 3.4 days compared to mean vase life for the initial sample population. Increases in vase life means for days to bending, folding, and wilting were 0.3, 3.5, and 1.2 days, respectively. Plants with flowers which senesced due to wilting had the longest mean vase life before and after breeding. Changes in proportion of senescence modes were observed; bending decreased, folding and wilting increased. Frequencies of bending, folding, and wilting were compared to vase life means for 10 progenies. Proportion of bending generally decreased as vase life increased.

Intensive selection to improve vase life was performed on a sample population of Gerbera ×hybrida Hort. from a broad source of germplasm. Progeny of a 5 × 5 diallel cross yielded estimates of narrow sense heritability (h 2 = 0.28) and broad sense heritability (H2 = 0.28) for vase life based on a mean of 1.96 measurements per plant. Additive gene action is postulated to control this character since the difference between total genotypic variance and additive genetic variance components was small. Repeatability (r = 0.57) based on a single measurement per plant was moderately high. Heritability estimates were also determined based on 1, 2, 3, 5, and ∞ measurements per plant. Heritability ranged from 22% to 39%. Gerbera ×hybrida is a popular cut flower, but its postharvest performance is often less than desirable. Postharvest treatments (i.e., floral preservatives) are used to enhance the vase life of gerbera (Accati, 1989) but developing cultivars with genetically superior postharvest longevity may provide the consumer with a reliable expectation for postharvest quality. Therefore, research to evaluate the potential of plant breeding as a method to improve vase life in gerbera is important. Estimates for heritability of vase life have been previously reported. However, estimates can vary based on the population of plants evaluated, selection intensity, mating design, and environ- ment (Simmonds, 1979). Serini and De Leo (1978) concluded that selection should be based more on families than individual plants, since their estimate of narrow sense heritability was higher among full-sib families (h 2 = 0.67) than among plants (h 2 = 0.17). Tesi (1978), using clones from a population of Gerbera jamesonii with semi-double flowers, concluded that vase life is strongly influ- enced by environmental factors. He observed only 15% of the phenotypic variation in vase life was due to genotype (h 2 = 0.15). Harding et al. (1981) based their results on a nonrandom sample population of gerbera genotypes from their Davis population, which consisted of half-sib families and clonal parents. They concluded that since narrow sense heritability (h 2 = 0.24 and 0.38) and broad sense heritability (H 2 = 0.36 and 0.46) were moderately low for two successive generations, either intense selection or selection over a large number of generations would be required to increase mean vase life. Harding et al. (1987) compared their earlier average estimate of narrow sense heritability (21%) to a new average of narrow sense heritability (18.5%). Both averages were calculated using data from three generations of half-sib family mating. Realized heritability estimated from the ratio of the selection response to the selection differential was about 30%. The objectives of this study were to determine narrow sense heritability and broad sense heritability of vase life by diallel analysis using a broad based source of germplasm.

OBJECTIVE: To examine the rate of weight gain over time among Americans by age, gender, and race. PARTICIPANTS: Scientific sample of 5117 Americans, ages 25–74?y in 1971 followed for 20?y. RESULTS: Rates of weight gain estimated by mixed effects models are highest among young adults and rates of weight loss are greatest among older adults. The overall shape of the growth curves are similar for men and women, black and white, in terms of both weight gain and weight loss. Rates are also affected by baseline body mass index (BMI=wt in kg/height in m2). CONCLUSIONS: Americans gain weight until middle age, stabilize, and begin to lose weight near age 60. Weight loss during old age is especially evident for obese Americans. The ability to accurately identify groups with increased risk and target them for obesity prevention will help combat the steady rise of overweight and obesity in America.

Procedures for in vitro establishment, rapid shoot proliferation, and ex vitro plantlet acclimatization of Cryptocoryne lucens de Witt were determined. Shoot cultures were established from surface-sterilized shoot tips cultured on Linsmaier and Skoog salts and vitamins medium (LS) solidified with 0.8% (w/v) agar and supplemented with 2.0 µM BA and 0.5 µM NAA. The effect of BA (0 to 20 µM) and 0.5 µM NAA on shoot multiplication from single-node and clustered triple-node shoot explants was determined after 35 days. The most efficient shoot proliferation (7.7 shoots/explant) occurred from single-node shoot explants cultured on LS + 20 µM BA and 0.5 µM NAA. Maximum plantlet establishment was achieved by direct sticking of triple-node (cluster) microcuttings in either soilless planting medium or polyurethane foam cubes. Production of highly branched salable plants from microcuttings was possible within 18 weeks. Chemical names used: N-(phenylmethyl) -1H-purin-6-amine (BA); 1-naph- thaleneacetic acid (NAA). The genus Cryptocoryne (Araceae) con- tains some of the most commercially impor- tant ornamental aquatic species used in the aquarium plant trade (Rataj and Horeman, 1977). Most cryptocorynes are native to southeast Asia and Indonesia and grow either

We studied the relationship of malpractice claims and the personal, educational, and practice characteristics of a sample of surgeons (n = 427). The surgeons were members of a physician-owned malpractice trust and represented all those who had fewer than 0.13 malpractice claims per year and those with more than 0.54 claims per year. Data are reported separately for orthopedic surgeons (148), obstetrician-gynecologists (115), and a mixed group of other surgeons (164). The last group included otolaryngologists, neurosurgeons, and general, vascular, thoracic, and plastic surgeons. We studied the relationship between the number of malpractice claims (ranging from no history of claims to those terminated from the trust because of high rates of claims) and the surgeon's personal, educational, and practice characteristics. The major differences were between the surgeons who were terminated because of a high number of claims and those with few or no claims. Terminated surgeons were less likely to have completed a fellowship, belong to a clinical faculty, be members of professional societies, be graduates of an American or Canadian medical school, have specialty board certification, or be in a group practice. The data also suggest that orthopedists with high numbers of claims may be less likely to have a religious affiliation or to have a registered nurse working in their office practice. These findings suggest that surgeons with lower claim rates may be more likely to manifest exemplary modes of professional peer relationships and responsible clinical behavior.

The effect of postharvest dips on the longevity of Anthurium andraenum cultivar Nitta and Alpinia purpurata was evaluated. The inflorescences were dipped in a 200 ppm benzyladenine (BA) solution, an antitranspirant, or water for 10 minutes. After dipping, anthuriums were placed directly in water and gingers were placed in either water or a 2% sucrose solution and placed in interior conditions (10 μmol m-2s-1 for 12 hr/day, 21±2C). Ginger longevity was increased by 10 days or more by the sucrose solution. The greatest longevity of gingers was obtained when dipped in either BA or the antitranspirant and held in the sucrose solution. Anthurium longevity increased 10 days when dipped in BA, while the other treatments had little effect.

Cultivars of Kalanchoe blossfeldiana Poelln. varied in number of long nights required for complete flower initiation and development. ‘Montezuma’ and ‘Texas Sunset’ requried 14 long nights, while ‘Pixie’, ‘Nugget’, ‘Cactus Candy’, ‘Goddess’, ‘Tobasco’, ‘Osage Orange’, ‘Toltec’, ‘Adobe Rose’ and ‘Rotkappchen’ required 15 to 28 nights. Height of apical meristems increased in ‘Montezuma’ after 7 long nights, but changes were not evident in ‘Pixie’ until 9 long nights. Scanning electron microscopic analysis showed first evidence of sepal primordia in ‘Pixie’ after 28 long nights—6 nights later than ‘Montezuma’. Differences in the number of long nights required for flower induction were related to delayed floral initiation rather than organogenisis or maturation.

Aphelandra squarrosa Nees. plants grown under 250 μmol s−lm−2 photosynthetically active radiation (PAR) were transferred to 265, 737, and 1070 μmol s−1m−2. Stomatal density and number of palisade layers of newly expanded leaves decreased linearly after 2 months, while number of countable chloroplasts per palisade cell increased linearly as light intensity decreased. Number of countable chloroplasts per palisade cell decreased and palisade layers increased in mature leaves transferred to higher PAR levels. Stomatal density and guard cell length in mature leaves did not change. There were nonlinear responses to PAR levels in number of marginal collenchyma cells, leaf thickness, and palisade cell length of immature leaves. Chloroplasts in mature and immature leaves were less discrete and more tightly appressed to anticlinal palisade cell walls as PAR levels increased.

Florida's ornamental horticulture industry, like the vegetable and fruit industries, has been shaped by Florida's long growing season, mild winters, and high light levels.

Phalaenopsis species often exhibit light green spots and/or pitting of the upper leaf surface during winter and spring. Results of this study indicate spotting and pitting can be induced by exposure to temperatures of 2°, 4°, and 7°C for 8 hours or less. The spots and/or pitted areas were always found between large vascular bundles. Light green or yellow spots on the leaves were caused by hypertrophied mesophyll cells between the main vascular bundles. Anatomical observations revealed the pitting was due to collapsed mesophyll cells. Severity of response depended on physiological age of the leaf and duration of exposure to the chilling temperature.

Gibberellic acid (GA)-treated ‘Redwing’ azaleas (Rhododendron spp.) flowered in half the time required for cold-treated plants. Visual plant quality and flower uniformity were equal in both treatments. Ethylene evolution of buds was monitored in plants receiving cold treatment, receiving GA application, or remaining in the greenhouse without a dormancy-breaking treatment. Ethylene was not detectable in untreated plants or in cold-treated plants during cold treatment. Ethylene in buds was detected on the 4th day after removal from the cooler and was found to correspond to ethylene generation in GA-treated plants.

Lisianthus russellianus Hook., syn. Eustoma grandiflorum, belongs to the Gentianacea and is native from the plains of Nebraska to Louisiana and Mexico. It is a tender annual, grows 45 cm high, and produces 5 lobed, purple, dark-eyed flowers in summer and fall. The flowers have been described as large as 10 cm across under favorable conditions and to number as many as 10 or more on a plant. Flowers have lasted up to 2 weeks.

Silvernerve plant (Fittonia verschaffeltii ssp. argyroneura Coem.), a chill-sensitive foliage plant, was subjected to 2°, 5°, and 8° ± 1°C for 0, 2, 4, or 8 hours. Chilling temperatues caused leaf wilt, inflorescence collapse and brown necrotic spots on the foliage. Severity of chill damage increased with temperature reduction and duration.

Platyceriums (staghorn ferns) are propagated commercially by 2 methods: asexually by offshoots and sexually by spores. Many of the Platycerium species (e.g. P. stemaria, P. bifuractum) reproduce asexually by offshoots from roots or rhizome quite readily and are easily increased by removal of these offshoots. However, some of the larger and more sought after species (e.g., P. wandae, P. grande, P. superbum) do not produce offshoots or do so sparingly. These species must be propagated sexually through the use of spores. This technique is generally slow and may require 2-4 years to obtain a marketable plant. Rapid propagation of these slow growing staghorn ferns through tissue culture could prove to be economically beneficial to the foliage industry.