associated with poor or sporadic germination might be avoided if a treatment were developed to control hypocotyl and radicle length so that previously germinated seeds could be sown mechanically and 100% stand establishment could be achieved. Several
Nicole L. Waterland and Richard J. Gladon
Rochelle R. Beasley and Paula M. Pijut
for conservation, mass propagation, and genetic improvement of black ash. Thus, the aim of the present study was to develop a complete protocol for plant regeneration of black ash from hypocotyls for further use in genetic transformation studies
Po-Lung Chia and Chieri Kubota
, alternatives such as grafting became increasingly viable. Producing seedlings with long hypocotyls is desired in vegetable grafting for the reasons described subsequently. The position of the graft union must be high enough to prevent the vulnerable scion from
Ze Li, Xiaofeng Tan, Zhiming Liu, Qing Lin, Lin Zhang, Jun Yuan, Yanling Zeng, and Lingli Wu
. oleifera that decreases the regeneration period. Adventitious shoot organogenesis is an easy and fast plant regeneration method that can be induced via direct or indirect pathways. Hypocotyl explants have been used to achieve regenerated plants in many
Jane Kahia, Peter Kanze Sallah, Lucien Diby, Christophe Kouame, Margaret Kirika, Simeon Niyitegeka, and Theodore Asiimwe
Skoog media (1962) and incubated in a growth room maintained at 25 °C and 16 h photoperiod for 2 months. Explants (hypocotyls, leaves, and roots) harvested from the in vitro germinated plants using a sterile surgical blade and cut into 1 cm 2 leaf
Nichole F. Edelman, Bethany A. Kaufman, and Michelle L. Jones
response, which includes an exaggerated apical hook, hypocotyl thickening, and reduced hypocotyl elongation ( Knight et al., 1910 ). This response has been used in genetic screens to identify ethylene response mutants, including the etr1-1 mutation, which
David G. Clark, Christopher Dervinis, James E. Barrett, and Terril A. Nell
Florida Agricultural Experiment Station journal series R-07081. Use of a seedling hypocotyl elongation assay as a genetic screen for ethylene sensitivity of seedling geranium cultivars. The cost of publishing this paper was defrayed in part
M.E. Hoenecke, R.J. Bula, and T.W. Tibbitts
Light-emitting diodes (LEDs) with high-intensity output are being studied as a photosynthetic light source for plants. High-output LEDs have peak emission at ≈660 nm concentrated in a waveband of ±30 nm. Lettuce (Lactuca sativa `Grand Rapids') seedlings developed extended hypocotyls and elongated cotyledons when grown under these LEDs as a sole source of irradiance. This extension and elongation was prevented when the red LED radiation was supplemented with more than 15 μmol·m-2·s-1 of 400- to 500-nm photons from blue fluorescent lamps. Blue radiation effects were independent of the photon level of the red radiation.
M. ODA, K. Tsuji, K. Ichimura, and H. Sasaki
Horizontal grafting, in which scion and rootstock are cut and grafted horizontally at the hypocotyls, is essential for mechanization of grafting. The present studies have been conducted to improve the survival ratio and the growth of cucumbers grafted on Cucurblta spp. through horizontal grafting at the hypocotyls. The survival ratio of `Nankyoku 2' (Cucumis sativus) which had six vascular bundles at the hypocotyl was different when it was grafted on `Unryuh' or 'Kongoh' (C. moschata), six vascular bundles. The survival ratio of the scion grafted on `Dairoku' (C. maxima) which had twelve vascular bundles was the lowest. It was found that the survival ratio inversely correlated with the difference in the diameters of the hypocotyls of the scion and the rootstock. Fresh and dry weights of survival scions on `Unryuh' and `Kongoh' were almost same and heavier than that on `Dairoku'. It is suggested that minimizing the differences in the diameters and the numbers of the vascular bundles of the hypocotyls between the scion and the rootstock promotes the survival ratio and the growth of cucumbers which are horizontally grafted on Cucurbita spp..
Kenneth R. Schroeder and Dennis P. Stimart
One-centimeter hypocotyl explants from 2-week-old Antirrhinum majus L. (snapdragon) seedlings germinated and grown in vitro under 12-h cool-white fluorescent light and 12 h dark or 24 h dark were placed on Murashige and Skoog (MS) medium containing 0, 0.44, 2.22, 4.44, 8.88, or 44.4 μM N6-benzyladenine (BA). Cultures were maintained under the light/dark regime at 25°C. After 2 weeks, adventitious shoots were counted. A shoot was considered adventitious and counted if a stem and leaf developed. Shoots developed along the entire length of the hypocotyl sections. Mean shoot production per hypocotyl explant ranged from 2.4 to 6.1 shoots when seedlings were germinated and grown in 24 h darkness and 2.2 to 10.9 shoots when started in the light/dark regime. Highest shoot counts were attained /from hypocotyl explants when seedlings were germinated and grown under the light/dark regime for 2 weeks and transferred to 2.22, 4.44, or 8.88 μM BA. Shoot development appeared normal at the 2.22 and 4.44 μM level, while at 8.88 μM BA, development was slightly abnormal along with slightly more callus production.