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Abstract
‘Kiowa’ pecan [Carya illinoensis (Wang) K. Koch] is a precocious and prolific bearer whose nuts resemble those of ‘Desirable’ in size and shape but have a thinner shell. This hybrid meets the industry demand for a cultivar that produces heavy crops of large attractive nuts for marketing in shell. It has performed well in the Southwestern U. S. where it has been tested thoroughly. ‘Kiowa’ shows commercial potential under a rigid fungicide spray program in the humid Southeast, where testing has been limited.
Although the size of pot mums can be controlled with retardants, the use of such chemicals may become limited. Genetically dwarfing current cultivars may be an alternative. Using a construct including a chimeric oat phytochrome structural gene, tobacco phenotypes have been produced that strongly resemble retardant-treated plants. We wished to insert this construct in mum by using particle bombardment and determine the effects on plant size and flowering dynamics. A target system was developed using `Iridon' mum leaf sections regenerated on an IAA/BA medium. Shoots developed from surface cells principally at the cut edges. Regenerates were grown-on through flowering and no visual aberrations were apparent. Levels of 50 to 100 mg/l kanamycin were inhibitory to bud development. Sections were exposed to gene transfer and shoots recovered that appear resistant to kanamycin. Some appear chimeric while others appear to be escapes stimulated by a `feeder' effect from nearby transformed cells. Further analyses will determine whether some plants are stably transformed. (Supported by a Duffett Research Grant from Yoder Brothers, Inc.)
Taxol, a promising anticancer drug, is limited by inadequate supply. The production of taxol and related compounds (taxanes) by Taxus tissue cultures has been reported, yet sustained production has not been demonstrated. One theory is that cell differentiation and/or tissue organization is required to sequester taxol and avoid autotoxicity. To investigate this, T. cuspidata shoot cultures were established and the taxane content of various culture stages compared to that of field needles. HPLC analysis identified two peaks which comigrated and had UV spectra identical to taxol and 10-deacetyl taxol. The levels of 10-deacetyl taxol were similar in all samples. Cultured shoots contained much less taxol than field needles, and the level of a third peak which migrates closely to taxol was inversely related to that of taxol. Taxol content was restored in the first flush out of culture. Shoot cultures of T. brevifolia, T. x media, and T. canadensis have also been analyzed. In addition to shoot cultures, nodule cultures, a biological unit that may be suitable for production of taxanes in plant bioreactors, have been initiated and characterized.
Abstract
A method was devised to use honey bees and cages For controlled interpollinalion of numerous planl introduction accessions grown for seed increase. Honey bees (Aphismellifera L.) were maintained for 4 months (June-September) in small nuclei (min-ihive) for use in pollinating various crops grown under cages for seed increase. The nuclei remained as effective pollinating units without dwindling, swarming, overcrowding, starvation, or any of the other problems associated with extended maintenance of small pollinating nuclei. Cages used were easily assembled and stored, and were practical Tor caging large numbers of plantings for controlled pollination. Seed vields were excellent and of good quality.