Academic literature on the topic 'Watsonia – Flowering'

The sub-Saharan and mainly western southern African genus Babiana (Iridaceae–Crocoideae) is morphologically diverse, containing some 80 species. The Socotran B. socotrana, which differs from all other members of the genus inter alia in its trisulcate pollen grains, basic chromosome number, x=10, corms of axillary origin, and globose, colliculate–tuberculate seeds, is here excluded from Babiana and referred to the new genus Cyanixia. Other Babiana species have monosulcate pollen grains with a two-banded operculum, a basic chromosome number of x=7, terminal corm ontogeny, and derived pear-shaped seeds with a smooth glossy surface. Cyanixia socotrana was previously assigned to Babiana because of superficial similarities in morphology, including plicate leaves and blue flowers, thought at the time to be bilabiate, although now known to be actinomorphic and rotate. DNA sequence analysis using the chloroplast gene matK confirms that Babiana is a monophyletic assemblage, whereas B. socotrana is sister to the Lapeirousia/Savannosiphon clade of sub-Saharan Africa. The latter shares axillary corm ontogeny with the southern African Micranthus, Thereianthus, and Watsonia, in contrast to the more common situation in Crocoideae (including Babiana) in which the corm develops from the base of the flowering stem. The tropical African Zygotritonia, which also has axillary corm development, shares with Cyanixia a trisulcate pollen grain, but it differs markedly from that genus in its small, zygomorphic flower, undivided style, and basic chromosome number x=8. Cyanixia is here described as a new monotypic genus of Crocoideae, probably most closely allied to Savannosiphon, also a monospecific genus.

Luther Burbank (1849–1926) was a prolific ornamental plant breeder, who worked with 91 genera of ornamentals, from Abutilon to Zinnia, and released nearly 1000 cultivars to the industry. His innovative work included both herbaceous and woody plant materials as well as ornamental vegetables such as corn, tomatoes, and spineless cacti. His most popular ornamental release, the shasta daisy hybrids—first released in 1901, is still on the global market. This article focuses on Luther Burbank’s breeding techniques with ornamental plants and how both the germplasms that he developed and his methodologies used permeate modern flower breeding. Genera with the highest number of cultivars bred and released by Burbank include Amaryllis, Hippeastrum, and Crinum followed by Lilium, Hemerocallis, Watsonia, Papaver, Gladiolus, Dahlia, and Rosa. With Lilium, he pioneered breeding the North American native lily species, particularly those from the Pacific coastal region, producing the eponymous Lilium ×burbankii. Burbank’s breeding enterprise was designed to be self-sustaining based on profits from selling the entire product line of a new cultivar or crop only to wholesale firms, who then held exclusives for propagation and selling, although financial hardships necessitated selling retail occasionally. Entire lots of selected seedlings were sold to the highest bidder with Burbank setting the price in his annual catalogs such as the Burbank Hybrid Lilies lot for U.S. $250,000 or some of the “very handsome, hardy ones” for U.S. $250 to U.S. $10,000 each. Other flower cultivars also commanded high prices such as seedling Giant Amaryllis that sold for U.S. $1.55/bulb in 1909. Cacti were another area of emphasis (he released more than 63 cultivars) from the spineless fruiting and forage types (Opuntia ficus-indica, O. tuna, O. vulgaris) to flowering ornamentals such as O. basilaris, Cereus chilensis, and Echinopsis mulleri. Interest in cacti during 1909–15 rivaled the Dutch Tulip mania with exorbitant fees for a single “slab” of a cultivar, speculative investments, controversy with noted cacti specialists (particularly David Griffiths), and lawsuits by The Burbank Company. Although most cultivars have been lost, Burbank’s reputation as the Father of American Ornamental Breeding remains admirable from critics and devotees alike.

The kalanchoe (Kalanchoe blossfeldiana) is an important ornamental species belonging to Crassulaceae. This plant is grown in commercial greenhouses. A survey revealed infections of broomrape, Orobanche aegyptiaca Pers. (syn. Phelipanche aegyptiaca Walp.), on kalanchoe plants in the province of Tehran (Pakdasht, 35°26′ N, 51°40′ E, 1,003 m elevation) in northern Iran in January 2014. About 1% of total Kalanchoe pots in a greenhouse were infected. The infection of kalanchoe was confirmed by verifying the attachment of the broomrape to the kalanchoe roots. Broomrape plant heights (from the soil surface) were between 13 and 28 cm, with flowering stems 5 to 14 cm. The stems were erect, unbranched, slender, 2 to 4 mm diameter, glandular-pubescent, pale yellowish, and inflorescent rather than lax. The leaves were reduced to bracts up to 3 to 6 mm long. There was one bract and two bracteoles surrounding each flower. The bracts measured 4 to 5 mm, had ovate lanceolates shorter than the calyces, and filiform, lanceolate bracteoles measured 5 mm. The calyces measured 4 to 6 mm, and were gamosepalous, hairy, and glandular. Corollas measured 22 to 28 mm, and were medium slate blue with darker veins, slightly curved, conspicuously infundibuliform, and glandular-pubescent. Stamens were epipetalous, inserted 5 mm above the corolla base, filaments (10 to 12 mm) hairy below, anthers were villous. Style (18 to 21 mm) and stigma lobes were light steel blue. Ovary measured 5 to 7 mm. O. aegyptiaca is the most important species of the broomrape, which parasitizes important crops, such as tomato, potato, tobacco, carrot, celery, mustard, and spinach, as well as some ornamental plants, such as chrysanthemum (1,2). In this survey, low infection did not lead to visible symptoms or damage to kalanchoe, but allowed seed production by the parasite. However, the parasite weed could pose a serious threat to production of this important ornamental plant at high infection. To our knowledge, this is the first report of O. aegyptiaca parasitism on kalanchoe in Iran. Additionally, to the best of our knowledge, this finding reports the first occurrence of a Crassulaceae plants as a host for O. aegyptiaca. References: (1) I. Ghannam et al. Am. J. Plant Sci. 3:346, 2012. (2) J. Rumsey and S. L. Jury. Watsonia 18:257, 1991.

The flowering morphology of the erect, thorny, primocane-fruiting blackberry (Rubus L. subgenus Rubus, Watson) cultivars ‘Prime-Jan’ and ‘Prime-Jim’ were studied in 2005 and 2006 in Aurora, OR. Primocanes that were “soft-tipped” in early summer to 1 m were compared with untipped primocanes. In both years, soft-tipped primocanes developed two- to threefold more branches and almost twice the number of flowers as untipped canes. ‘Prime-Jan’ and ‘Prime-Jim’ began blooming on the branches of soft-tipped canes in mid-July, whereas untipped primocanes began to bloom in late July in 2005 and 2006. Within a primocane inflorescence, the terminal or distal flower was always the first to open followed by terminal flowers from axes located on the basal portion of the inflorescence. Flowers then opened acropetally within the inflorescence, with the exception of the most basal flower, which was typically the last to open. The blooming pattern within an inflorescence was similar for soft-tipped and untipped primocanes. Days from anthesis to black fruit for soft-tipped and untipped primocanes averaged 45 to 51 d in both years, depending on cultivar.

The scientific and organizational activities of the worldwide known scientist in the field of molecular biology James Dewey Watson were described in this article. 55 years ago James Watson and Francis Crick made one of the key discoveries of the twentieth century. They have found that DNA has a double helix structure. This discovery was based on the X-rays patterns obtained by Maurice Wilkson and Rosalind Franklin. Subsequently, this DNA model had been proved, and J. Watson and F. Crick were awarded with the Nobel Prize in Physiology or Medicine in 1962. Since, our knowledge of the main molecule of life has been greatly expanded. A significant flowering of molecular genetics has began: synthesis of RNA and DNA in vitro, decoding of genetic code, recombinant DNA technology, genetic engineering, sequencing of genomes and post genomic technologies. James Watson is one of the authors of the cell biology classic textbook “Molecular Biology of the Cell”. In addition, he has developed the current areas of molecular biology such as molecular oncology and molecular neurobiology. Today genomes of different animals and humans have been decoded and the functions of many genes have been determined. But at present still unknown how the DNA starts and how it affects the work of the organs and the organism as a system. Keywords: James Watson, DNA structure, Nobel Prize in physiology or medicine, Molecular Biology of the Cell.

The role of light and temperature on flowering of South African Watsonia species were evaluated to assess the potential for this genus as a commercial flower crop. Species were selected that represent different climatic regions of South Africa, with the aim of understanding how ecologically distinct species perform under cultivation. The four selected species were W. borbonica and W. tabularis (winter-rainfall area), W. angusta (shared rainfall) and W. pillansii (summer-rainfall area). In order to establish the optimum temperature required for flowering, plants were exposed for 12 weeks to three temperature regimes (12/7 °C, 21/15 °C and 29/21 °C) after attaining their first and/or second leaves. A temperature shift of 12/7 °C was used to assess if the plants had a vemalisation requirement. Controls were maintained under 25 % shade under natural conditions, with an average temperature of 24/7 °C. An elevated temperature of 29/21 °C was detrimental to plant growth. Moderate temperatures of 21/15 °C significantly (P<0.001) increased the height and the number of leaves produced per plant relative to the 12/7 °C treatment. These temperatures significantly (P<0.001) increased the total number of flowers produced per plant compared to low temperatures. However, flowering percentage and quality of flowers were reduced. A low temperature regime of 12/7 °C was efficient in satisfying vernalisation requirements and inducing flowering in four selected species. However, the total number of leaves produced per plant was signifcantly reduced. The summer-rainfall species, W pillansii, displayed a qualitative response to vernalisation, as no flowering was observed in non-vernalised plants. Two winter-rainfall species, W borbonica and W. tabularis, demonstrated a quantitative response to vernalisation. These species flowered at non-vernalising temperatures. W angusta behaved like the winter-rainfall species in terms of flowering. Overall, a vernalisaton treatment marginally reduced days to flower while flowering percentage was increased compared to other temperature regimes. However, there was no increase in the total number of flowers produced per plant. Low temperatures were not only effective for flower induction, but also for releasing corm dormancy, thus synchronising growth. Storing corms at either 4 or 10 QC resulted in 100 % sprouting within 4-6 weeks. The role of daylength in flowering of Watsonia plants was established by subjecting plants to long days (LO) of 16 h light and 8 h dark and to short days (SO) of 8 h light and 16 h dark. The number of leaves and flowering were significantly (P<0.01) promoted under the LO regime. However, there was strong temperature and daylength interaction in terms of flowering potential, as at low temperatures flowering was induced irrespective of daylength. In W. pillansii, flowering was obtained under both regimes (LO and SO) applied at the second leaf stage. Flowering in W. borbonica and W. tabularis was only observed under the LO regime at the second leaf stage. In both species, flowering was also obtained in SD-treated plants, provided treatment occurred after the formation of the third leaf. However, the total number and quality of flowers were reduced. To examine the effect of light intensity on flowering, plants at different developmental stages (first and/or second or beyond the third leaf stage) were exposed to photosynthetically active radiation (PAR) of 150 jJmol m-2s-1 or 39.5 jJmol m-2s-1 for 7 weeks. Exposure to low light intensity at either developmental stage compromised leaf quality. No flowering was observed following low light intensity treatment during the first to third leaf stages, even though plants were exposed to low temperature and LO regimes, both of which promoted flowering. Observation of the shoot apical meristem revealed that the second leaf stage was critical as the anatomical transition to flowering occurred at this level. When beyond the third leaf stage, low light intensity did not prevent flowering. However, the number of flowers produced per plant was reduced compared to plants maintained at 150 jJmol m-2s-1. Thus, light intensity played a role in both plant morphogenesis and flowering. LDs were effective in promoting vegetative growth whereas high light intensity and low temperature regimes played pivotal roles in flower induction. This makes them useful horticulture tools to produce desirable Watsonia plants for commercialisation.
Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.