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Margaret R. Pooler and Ruth L. Dix

Interspecific hybridizations among members of the genus Hamamelis (the witchhazels) and Corylopsis were carried out in 1993, 1994, 1995, and 1996 at the U.S. National Arboretum. Specifically, crosses involving the native witchhazel (H. vernalis and H. virginiana) and the Asian taxa (H. mollis, H. japonica, and H. × intermedia) were attempted in order to combine the ornamental qualities of the Asian species with the adaptability and fall blooming characteristics of the native species. Additionally, C. platypetala, a hardy species with small inflorescences, was crossed with C. himalaica, which has large showy inflorescences but is less hardy. Approximately 50 seedlings resulting from these crosses have been analyzed using randomly amplified polymorphic DNA (RAPD) markers to verify interspecific hybridization. Based on these assays, we report the first incidence of controlled interspecific hybridization between the Asian and native witchhazel taxa.

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Alan R. Biggs

The proportion of spurs blooming on `McIntosh' apples (Malus domestica Borkh.) was reduced significantly in 1986 and 1988, but not in 1987, following seasonal programs of six bitertanol or flusilazole treatments applied at two and three rates, respectively. The fungicides were not associated with any visible phytotoxic effect nor was shoot length reduced by any fungicide treatment. In two of three experiments conducted in May and June 1986, transpiration was reduced by the low rate of flusilazole and the high rate of bitertanol relative to both the captan and nonsprayed trees. In all three experiments, flusilazole at 1.4 g a.i./100 liter was associated with transiently reduced transpiration rates, lasting a minimum of 48 hours, relative to the nonsprayed control. Fungicides affected the diffusive resistance of apple leaves in all three experiments; however, there were no consistent treatment effects on diffusive resistance among the three experiments.

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Lijuan Wang, Nian-Oine Shi, Murray E. Duysen, and Chiwon W. Lee

Cleistogamy in Salpiglossis sinuatu L. involves a sequence of events, including arrested corolla development, precocious pollen germination inside anther, pollen tube penetration of the pistil, and eventual self fertilization, that takes place. within a tightly closed flower bud. A single dominant gene (C) controls cleistogamy in this plant. During early blooming period, cleistogamous (CC, Cc) plants produce both chasmogamous (open) and cleistogamous (closed) flowers. Enzymes in various tissues of both cleistogamous and chasmogamous buds were detected by isozyme banding patterns in starch gel electrophoresis. The onset of cleistogamy may be signalled in the calyx and corolla tissues in the early stage of flower development. The levels of specific enzymes (PGM, PGI, G-6PD, PGD, MPI) involved in gluconeogenesis, pentose phosphate shunt and glycolysis in both calyx and corolla tissues of the cleistogamous buds were greatly reduced. These enzymes were present in the pistil and anthers of cleistogamous buds and in all floral parts of the chasmogamous buds.

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T.G. Beckman, W.R. Okie, and S.C. Meyers

Rootstock influence on bloom date and fruit maturation of `Redhaven' peach [Prunus persica (L.) Batsch] was studied over a 3-year period. Rootstock included seedlings (Lovell, Halford, Bailey, and Siberian C) and cuttings (GF677, GF655.2, Damas 1869, and `Redhaven'). Bloom dates of the various combinations differed in all 3 years, with a range of 3.6, 9.1, and 7.3 days in 1988, 1989, and 1990, respectively. Fruit development period differed each year with a range of 3.9, 5.8, and 4.4 days in 1988, 1989, and 1990, respectively. `Weighted-average harvest date also differed with a range of 3.6,2.9, and 5.6 days in 1988, 1989, and 1990, respectively. `Redhaven'/Lovell was the latest blooming and maturing combination in all 3 years of the study.

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Bridget K. Behe and Dennis J. Wolnick

We determined the influence of demographic characteristics and floral knowledge (measured as product experience) on the type of floral product purchased. A sample of 401 Pennsylvania residents was divided into fresh flower and flowering plant consumer segments. Results of discriminant analyses showed the two segments were moderately distinct. Purchasers of fresh flowers were younger and more likely employed outside the home than those who purchased flowering plants, but the latter had more blooming plants in their homes than did consumers of fresh flowers. Consumers of flowering plants and of fresh flowers did not differ in their level of floral knowledge or demographic characteristics. Minor differences were found between the two segments that were not substantial enough to justify distinct marketing strategies.

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Shujun YU

The author investigated, recorded, observed and analyzed the major wildflowers in Mount Huangshan---the natural and cultural heritages listed by the ESC0 of UN for the first time. On the basis of their desirable characteristics, more than 300 wild ornamental species are divided into 8 categories -–-historical old trees, rare and endangered species, evergreen ornamentals, blooming trees and shrubs, plants with colored foliage and fruit in fall, vines, herbaceous ornamentals and ground covers, and ornamental ferns. Mount Huangshan is one of the richest regions of native ornamentals in Eastern China and the most famous natural beauty in Pan-China. There are about 1500 wild landscape plants in and around it. Finally the paper puts forth some proposals and methods for introduction and utilization of wild ornamental plants. That is, investigation, classification,acclimatization and cultivation of them, and building a sort-out botanical garden for the germplasmic preservation and the flourishing landscape tourism.

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Hirotoshi Tsuda, Hisato Kunitake, Mai Yamasaki, Haruki Komatsu, and Katsunori Yoshioka

With crosses between colchicine-induced tetraploid shashanbo (Vaccinium bracteatum section Bracteata) and tetraploid highbush blueberry ‘Spartan’ (Vaccinium corymbosum section Cyanococcus), intersectional hybrids were produced. The hybridity of these plants was confirmed based on DNA markers and morphological characteristics. The morphological characteristics, blooming date, and ripening period of the hybrids were intermediate between those of the parents. Ploidy analyses by flow cytometry and chromosome counting revealed that these hybrids were tetraploid. Four hybrids set fruit in the field and these two hybrids showed high pollen stainability. It was noteworthy that fruit of two hybrids had high soluble solids concentration compared with ‘Spartan’ and the fruit pulp of the hybrids was tinged with red as shashanbo. These hybrids could be useful in breeding new cultivars with high sugar content, abundant phytochemicals, extensive environmental adaptability as well as late flowering and fruit maturity.

Open access

Richard W. Hartmann

Abstract

Tropical lines of Phaseolus spp. planted in Hawaii in spring or early summer included types which bloomed in the usual 30-45 days and types which did not bloom until days had begun to shorten in the fall. Short day types bloomed at daylengths between 113/4 and 131/4 hr, with the majority blooming between 121/2 and 13 hr. P. vulgaris, P. lunatus, and P. calcaratus included both short-day and day-neutral types. All lines of P. aconitifolius, P. acutifolius, and P. angularis were day-neutral. Single lines of P. erythroloma and P. cf. stenolobus were short-day, and single lines of P. pilosus, P. radiatus, and P. bracteatus were day-neutral.

Open access

Eiden J. Stang and E. L. Denisen

Abstract

Morphological differences exist in pre- and postdormant inflorescence and fruit development of concentrated ripening selections Iowa 23-6214 and 26-6215 when compared with nonconcentrated ripening strawberry cultivars ‘Midway’ and ‘Cyclone’. Inflorescences sectioned before dormancy, however, revealed no characteristics considered indicative of concentrated ripening. Stylar development in secondary and tertiary flowers of greenhouse grown, concentrated ripening selections was retarded in the early post-dormant period. In single harvests in the field and greenhouse, these selections had higher percentages of ripe and partially ripe secondary and tertiary fruit than ‘Midway’ and ‘Cyclone’. A high abortion rate and/or arrested development in late-blooming flowers was characteristic of concentrated ripening selections. Pedicel length and inflorescence branching habit were not correlated with developmental or ripening rates.

Open access

Dale E. Kester

Abstract

Effect of genotype on variation in chilling requirement among almond seed populations was studied. Pollen of different varieties used on the same seed tree changed embryo genotype and, subsequently, the chilling requirements of the populations of seeds produced. There was a direct correlation between time of bloom of seed and pollen parents and the length of chilling required by their offspring seeds. Chilling requirements were not significantly different in seed populations resulting from reciprocal crosses involving varieties of long and short chilling. Such seed populations had comparable genotypes but were exposed to different maternal effects. Embryo genotype was a controlling factor in determining seed chilling requirement in almond. A distinction between systems affecting inheritance of time of bloom in almond was shown in that ‘Tardy Nonpareil’, a late-blooming bud mutation of ‘Nonpareil’, transmits later bloom to its seedling offspring but did not transmit longer chilling to the seeds.