Группа авторов

Horticultural Reviews, Volume 49


Скачать книгу

href="#ulink_f7171d59-4223-5334-b3e3-92d42cc7c2b2">HISTORY AND DISTRIBUTION OF OAKLEAF HYDRANGEA

      5  MORPHOLOGY OF OAKLEAF HYDRANGEA

      6  BIOTIC AND ABIOTIC CONSIDERATIONS

      7  GENETICS AND BREEDING Ploidy and Genome Size Pollination Biology Breeding for Disease Tolerance/Resistance Breeding for Compactness Breeding for Cold Hardiness Breeding for Floral Characteristics Germplasm Resources Molecular Resources for Breeding Genetic Variation in Hydrangea

      8  CONSERVATION

      9  PROPAGATION

      10  FUTURE PROSPECTS

      1  LITERATURE CITED

      Hydrangeas have been important plants throughout history, with records of their use going back as far as ancient China (Mallet et al. 1992). Hydrangeas have had cultural impacts through use for medicine and ornamental horticulture. Various species have traditionally been used medicinally throughout East Asia (Long and Li 2004; Abe and Ohtani 2013; Singh 2016) and in southeast North America (Banks 1953; Cozzo 2004) for a variety of purposes, including treating abdominal pain, colds, fevers, and arthritis.

      In addition to being popular florist crops, plants in the genus Hydrangea are flowering shrubs that have been increasing in popularity in recent years as versatile and attractive landscape plants. This increase can in part be attributed to the introduction of remontant H. macrophylla Thunb. cultivars, notably, ‘Bailmer’ (Endless Summer® The Original) in 2004. Since then, other Hydrangea species have also experienced an increase in popularity. Although H. macrophylla has been well studied, other Hydrangea species have not received as much attention. H. quercifolia Bartr. (oakleaf hydrangea), in particular, has been little studied even though it is such a unique species.

      (Source: Photo credits: A. Sherwood.)

      A monograph for the genus was written by McClintock (1957), which divided Hydrangea into 23 species. Although this study was based entirely on herbarium voucher specimens, it has been the authority on Hydrangea taxonomy until recently, as evidence has been building for an updated classification. The plants in this genus are woody shrubs, lianas, or small trees, and either semi‐evergreen or deciduous. The inflorescences of Hydrangea species consist of many inconspicuous perfect florets surrounded by few to many conspicuous florets; the conspicuous florets typically contain four large petaloid sepals and have reduced fertility. Hydrangea flowers are mostly corymbs, with two notable exceptions; H. quercifolia and H. paniculata, which are the only Hydrangea species to have inflorescences in the form of panicles.

      Although historically Hydrangea was placed in the Saxifragaceae, newer genetic evidence (Morgan and Soltis 1993) supports Hydrangeaceae as its own family in the order Cornales. The Hydrangeaceae family consists of about 270 species within about 17 genera (De Smet et al. 2015). The family is divided into two subfamilies, Jamesioideae and Hydrangeoideae (Hufford et al. 2001). Subfamily Hydrangeoideae contains two tribes, Philadelpheae and Hydrangeeae (Soltis et al. 1995). Hydrangeeae contains nine genera and is further broken into two clades (or subtribes), named Hydrangea I and Hydrangea II (Samain et al. 2010). Other genera in Hydrangeeae are Deinanthe, Cardiandra, Schizophragma, Pileostegia, Decumaria, and Platycrater (Hydrangea I), and Dichroa and Broussaisia (Hydrangea II).