Impatiens Walleriana Hook Research Articles

Strategies for Mycorrhizal Inoculation of Six Annual Bedding Plant Species

We inoculated six common annual bedding plant species with the vesicular-arbuscular mycorrhizal fungus Glomus intraradices Schenck & Smith using two fertilizer P concentrations (3 or 15 μg·mL-1) and three inoculation timings (inoculation at sowing, at transplanting, or at both times). The plant species used were: Salvia splendens F. Sellow ex Roem. & Schult. cv. Firecracker Rose; Impatiens walleriana Hook. f. cv. Sun and Shade Royal Red; Tagetes patula L. cv. Girls Golden; Petunia ×hybrida Hort. Vilm.-Andr. cv. Freedom Blue; Coleus ×hybridus Voss. cv. Jazz Salmon; and Viola ×wittrockiana Gams. cv. Majestic Giant White. In general, Coleus, Petunia, and Viola were colonized more than were Impatiens, Tagetes, and Salvia. Inoculation at sowing required less inoculum than either of the other methods. Moreover, it was generally as effective in promoting colonization as double inoculation, and was often more effective than inoculation at transplanting. Mycorrhizal colonization was significantly reduced by the higher P concentration. The use of Myconate®, a water-soluble form of the flavonoid formononetin, significantly stimulated colonization in Salvia.

Inhibiting Growth of Flowering Crops with Ancymidol and Paclobutrazol in Subirrigation Water

Contamination of recirculated subirrigation water with growth retardants poses a potential problem for growers. Eight concentrations of ancymidol or paclobutrazol ranging from 0 to 100 μg·L-1 (0 to 1000 μg·L-1 for petunia) were supplied constantly in subirrigation water to potted plants to identify critical levels at which plant growth is affected. Concentrations of ancymidol resulting in 20% reduction in plant size relative to untreated controls were 3, 10, 98, 80, and 58 μg·L-1 for Begonia ×semperflorens-cultorum Hort. `Gin', chrysanthemum (Dendranthema ×grandiflora Kitam.) `Nob Hill', Impatiens walleriana Hook f. `Super Elfin Coral', Petunia ×hybrida Hort. Vilm.-Andr. `Madness Pink', and Salvia splendens Sell ex Roem. & Schult. `Red Hot Sally', respectively. Respective values for paclobutrazol were 5, 24, 17, 390, and >100 μg·L-1. The results provide useful information for managing potential growth retardant contamination problems or for applying growth retardants in subirrigation water. Chemical names used: α-cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidinemethanol (ancymidol); (±)-(R*,R*)-β-[(4-chlorophenyl)methyl]-α-(1,1-dimethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol).

アフリカホウセンカの流通段階における品質保持に及ぼすＳＴＳ処理および光環境の影響

Potted plants of Impatiens walleriana Hook. f. ex D. Oliver 'Super Erfin Scarlet' were acclimatized under various preharvest shaded conditions for 30 days and then subjectec to simulated postharvest florist shop conditions, i. e., 20°C and artificial lighting providec by fluorescent tubes.1. The shelf life of potted plants was affected by both pre- and postharvest light condi tions. Flower bud abscission was suppressed by a 60 to 80% reduction in light intensity during the 30-day preharvest period and a light intensity of 5.50W-m-2 after harvest. 2. Under such conditions, the leaves of acclimatized plants exhibited less L x b/|a| and had increased chlorophyll content which persisted under the simulated florist shop conditions. Foliar spray of 0.001mM silver thiosulfate (STS) applied at harvest just prior to shippirq effectively reduced flower bud abscission induced by low light intensity during the posthar vest period; but STS applications had no effect on preventing weak shoot growth. Light intensity of 3.5W•m-2 provided by 3-band radiation type fluorescent tubes, in combination with STS application, extended the shelf life of potted Impatiens plants up to 19 days.

Hybridization studies in the genus Impatiens

The biosystematic relationships of Impatiens walleriana Hook. f. and other selected species were examined by means of hybridization experiments and cytological techniques. Both I. gordonii Home and I. usambarensis Grey-Wilson hybridized with I. walleriana. Meiotic abnormalities of the hybrids were determined by examining pollen mother cells. Meiosis was regular in the majority of cells in both of the hybrids, but I. walleriana × I. gordonii had more abnormalities than I. walleriana × I. usambarensis. Because of the meiotic abnormalities in the hybrids and the morphological differences between I. walleriana and I. gordonii, I. gordonii was confirmed as a distinct species. The status of I. usambarensis was not as clear because it was morphologically similar to I. walleriana, and the hybrid between the two species had fewer meiotic abnormalities. Both I. gordonii and I. usambarensis could be useful in a horticultural breeding program because they hybridize easily with I. walleriana.