Search Results
Abstract
Multiple axillary shoots were obtained from Cordyline terminalis L. ‘Celestine Queen’, treated once weekly for 8 weeks with 6-benzylamino purine (BA) from 100 to 500 mg/liter. At 250-500 mg liter, 78% and 100% of the propagules of the chimeral clone were true-to-type.
The surface structure of rose (Rosa multiflora L. cv. Montse) leaves formed in vitro under several environmental conditions (light level, relative humidity) and with various growth regulator treatments was studied by light and scanning electron microscopy. The epidermis from leaves developed in cultures grown under a higher light level and a lower relative humidity (80 μmol·s-1·m-2 and 75% RH) than the conditions used in commercial laboratories (25 μmol·s-1·m-2 and 100% RH) showed anatomical modifications of the epicuticular wax, stomata, and epidermal cells similar to that of greenhouse-grown plant leaves. These results indicate that cultured plantlets can resemble greenhouse-grown plants under modified environmental conditions. In vitro pretreatment will reduce transplant losses and shorten the acclimatization period in the greenhouse.
Ploidy level was determined for six species and 88 cultivars of the Rhododendron subgenus Tsutsusi. High-resolution flow cytometry of nuclear DNA was performed on macerated plant tissue. All plants analyzed were diploid (2n = 26) with the exception of `Euratom', `Euratom Orange', and `Red Wing', which were triploid (3n = 39), and `Casablanca Tetra', which was found to be a cytochimera: mixoploid (2n + 4n) in the LI and LII, but tetraploid in the LIII. The described method has proven to be useful in screening a large population of rhododendrons. Analysis of different organs and plant tissues was easily accomplished through flow cytometry, and has proven useful in determining the ploidy of different histogenic layers.