Search Results
This cultivar originated from a grafting mutant in grafted plants of a selected 100-year-old seedling of Hibiscus syriacus L. for 5 years. In 1999, the plant is named H. syriacus `Andong'. Hibiscus syriacus `Andong' is a deciduous, erect-growing, multiple-stemmed, dwarf type that, in 7 years, has grown 120 cm high and 65 cm wide, with dense branching to the base. It has more than 200 flowers in a 7-year-old tree. The alternate, leathery, waxy, dark green leaves are 5.3 cm long, 3.8 cm wide. But it is 0.48 mm thick and 34.42 mg/cm2 of fresh weight and then is thickier and heavier than that of other cultivars. Therefore, the plant is rarely damaged by aphids and is reliably hardy to -20 °C. The flowers are white with a prominent dark red eye spot that radiates along the veins to midpetal, 5-7 cm in diameter, and blooms profusely from July to October. Total flowering time of `Andong' was 36 h in both 1998 and 1999. It sets very little fruit. AIt does not only germinate by pollen, but also by seeds. This cultivar can be readily propagated by softwood (on 24 July with 7000 ppm IBA in the mist) or hardwood cutting (1000 ppm IBA) and by grafting on seedling H. syriacus understock.
Abstract
Urea was applied to the foliage of 1-year-old apple Malus pumila Rehd., cv. Mailing Merton 106 (MM 106) trees during senescence and the fate of the urea C and N determined. The urea C was readily released as CO2, but abscised leaves still contained 18% of the total. Only 5% of the urea C was found in storage tissues (shoot bark and wood, stem bark and wood, and roots). By the time the leaves abscised, this C was found primarily in protein, sugars, and amino acids of storage tissues. Small amounts of urea were still present. The urea N was translocated from the leaves as amino acids or urea. At leaf abscission, 30% of the initial N was still present in the leaves. During senescence, storage tissues from untreated trees increased 1.5-fold in N while similar tissues from urea-treated trees increased 3-fold. This additional N was found primarily in stem and shoot bark and in the roots. Small amounts of N were stored as amino acids but the bulk of the urea N was stored as protein.
Abstract
Senescing apple leaves absorbed 80% of applied urea in 48 hr with greater absorption in light than in darkness. The amount of urea absorbed paralleled the increase in the concn of soluble N and urea N. The bulk of the increase in soluble N was urea and the changes in total soluble N paralleled the changes in urea N. During leaf senescence, chlorophyll, total N and protein declined and much of this N was translocated into storage tissues. Trees which received a post-harvest urea spray produced a significantly greater amount of shoot growth and fruit set of apples than trees receiving no urea or a soil application of urea. The yield was not significantly different between trees receiving a 5% urea spray and trees receiving the soil application of urea. However, the efficiency of N utilization by a 5% urea spray was 4-fold greater than the soil application.
New cultivars, `SKK 1' and `SKK 2', of Korean mountain ash (Sorbus alnifolia) that had superior morphological features as woody landscape plants were selected from 5000 seedlings of Sorbus alnifolia. Two clones with genetic variation were selected from 1983 to 1994 as landscape plants with large leaf and unique tree form: `SKK 1', which had large leaf and flower, and `SKK 2', with semi-weeping tree form. New selected cultivars of S. alnifolia were successfully grafted and inherited their mother characteristics. Sorbus alnifolia was difficult to propagate by cutting. Therefore, in vitro propagation methods might be used to propagate the superior cultivars. Shoots with apical and axillary buds were excised from 1-year-old seedlings. The explants were cultured on WPM supplemented with 0.5 mg/L BA. Shoots formed from initial cultures were subcultured at ≈4-week intervals onto the same media. To know the best hormone concentration in shoot multiplication, 0.1–3.0 mg/L of BA and 0.1–1.0 mg/L of zeatin were added to each WPM and MS media. The best shoot proliferation and elongation were obtained on MS medium with 1.0 mg/L BA from the whole shoot with the callus-like tissue, whereas the worst results were obtained from shoot tip. A 13-fold proliferation rate was achieved every 4 weeks.