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The current standard strategy for cotton transformation uses Agrobacterium for gene transfer and regeneration via somatic embryogenesis, but it is successful only for a handful of cultivars. This study was undertaken with the prospect of expanding the number of elite Upland cotton (Gossypium hirsutum L.) genotypes that can be regenerated via somatic embryogenesis. We tested 15 elite Upland cotton lines from Southeast germplasm: eight lines developed by the Georgia Agriculture Experiment Station and seven by the USDA-ARS Pee Dee cotton breeding program. These genotypes were tested on three embryo initiation-maturation media that were previously found to be capable of inducing somatic embryogenesis in diverse cotton species. Three Pee Dee lines, PD 97019, PD 97021, and PD 97100, and one Georgia line, GA 98033, responded to at least one of the three medium treatments. As expected, the regeneration efficiency of the Georgia and Pee Dee lines was relatively low as compared with the standard Coker 312 cultivar and a high degree of seed-to-seed variability was observed. However, the mean number of somatic embryos (SEs) per gram of tissues was high for the two best embryogenic lines, PD 97019 and GA 98033. Furthermore, the percentage of SEs that converted into plantlets for GA 98033 was comparable to Coker 312 for two of the three media tested., THE UPLAND COTTON genetic transformation strategy uses Agrobacterium-mediated transformation and regeneration via somatic embryogenesis. While Agrobacterium-mediated transformation is highly efficient in inserting transgenes into cotton cells (Sunilkumar and Rathore, 2001), [...]

To accomplish our objective of broadening the number of regenerable cotton lines, we developed a protocol capable of producing plants through somatic embryogenesis of diverse cotton species. Callus was initiated from hypocotyl and cotyledon explants on a callus initiation medium [CIM; modified MS with 1 mg [L.sup.-1] kinetin and 2 mg [L.sup.-1] naphthaleneacetic acid (NAA)]. Friable embryogenic callus was periodically selected and transferred onto callus selection/maintenance medium (CS/MM) [modified MS with 0.1 mg [L.sup.-1] kinetin and 0.5 mg [L.sup.-1] NAA]. The selected callus was then transferred into a liquid embryo initiation medium (EIM) (modified MS medium in which [NH.sub.4][NO.sub.3] was removed and [KNO.sub.3] amount doubled) followed by transfer to solid embryo maturation media [EMMS.sub.2] (0.5 mg [L.sup.-1] NAA + 0.05 mg [L.sup.-1] kinetin). The liquid step not only decreased the culturing time but also increased the number of embryos per gram of cultured tissue. Germinating somatic embryos were placed on MS medium with no hormones and plantlets were acclimatized before transfer to the greenhouse. Significant numbers of somatic embryos and their derived plantlets were obtained from a commercial cultivar of G. hirsutum, Deltapine 90 and G. barbadense accession GB-35B126 (PI-528306). The mean embryos per gram for Deltapine 90 on [EMMS.sub.2] were higher than those previously reported for Coker 312. Highly significant differences were found between the two genotypes for both embryo and plant production. To our knowledge, this is the first report of regeneration of G. barbadense through somatic embryogenesis., GENE TRANSFER into plants depends on having well-established tissue culture systems to regenerate plants from a single transformed cell. Whether Agrobacterium or biolistics is used, successful transgenic plant production is [...]

Hedychiums are multipurpose plants cultivated as ornamentals because of their multicolor and showy and scented flowers and as medicinal plants because of their essential oils that have been found to possess antimicrobial and insecticidal properties. There is often taxonomic and botanical confusion about Hedychium species and cultivars because of the apparent existence of more than one cytotype within several Hedychium species, most likely because of the ease with which these species hybridize. Nuclear DNA content (2C-DNA) was determined for the first time in 23 Hedychium species and hybrids. The 2C-values ranged from 1.70 pg to 3.98 pg. We also determined the chromosome number of one species, Hedychium stenopetalum, which was found to be diploid (2n = 2x = 34), supporting the widely held view that the basic chromosome number in Hedychium is x = 17, and the existence of different cytotypes is most probably attributable to natural hybridization. Our results should be helpful not only in clarifying the botanical and taxonomic confusion in Hedychium but also in paving the way for a sound breeding program for this increasingly important ornamental ginger. [ABSTRACT FROM AUTHOR]

The antimicrobial properties of essential oils have been documented, and their use as "biocides" is gaining popularity. The aims of this study were to analyze the chemical composition and assess the biological activities of Hedychium essential oils. Oils from 19 Hedychium species and cultivars were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) techniques. The antifungal and insecticidal activities of these oils were tested against Colletotrichum acutatum, C. fragariae, and C. gloeosporioides, and three insects, the azalea lace bug (Stephanitis pyrioides), the yellow fever mosquito (Aedes aegypti), and the red imported fire ant (Solenopsis invicta). Hedychium oils were rich in monoterpenes and sesquiterpenes, especially 1,8-cineole (0.1%-42%), linalool (<0.1%-56%), a-pinene (3%-17%), β-pinene (4%-31%), and (E)-nerolidol (0.1%-20%). Hedychium oils had no antifungal effect on C. gloeosporioides, C. fragariae, and C. acutatum, but most Hedychium oils effectively killed azalea lace bugs. The oils also show promise as an adult mosquito repellent, but they would make rather poor larvicides or adulticides for mosquito control. Hedychium oils acted either as a fire ant repellent or attractant, depending on plant genotype and oil concentration. [ABSTRACT FROM AUTHOR]

Plant-derived antifungal compounds are preferred to chemicals to reduce the risk of toxic effects on humans, livestock, and the environment. Essential oil extracted from rhizomes and plant extracts of ornamental ginger lily (Hedychium spp.) were evaluated for their antifungal activity against two fungi, Aspergillus flavus and Fusarium verticillioides, that produce two major classes of mycotoxins, aflatoxin, and fumonisin, respectively, on several crops. Essential oil or leaf extracts from several Hedychium species and varieties totally inhibited the growth of pre-germinated spores of A. flavus and F. verticillioides. Control of these two fungi by aqueous extracts of rhizome was not effective, although a reduced number of colonies was observed. In view of these results, essential oils or crude leaf extracts from Hedychium spp. need to be considered for the control of mycotoxin-producing fungi under storage conditions. [ABSTRACT FROM PUBLISHER]

The genus Hedychium consists of about 50 species, with increasing popularity as ornamentals and potential as medicinal crop plants, but there are no reports on somatic embryogenic regeneration of any member of this genus. The objective of this investigation was to establish an in vitro regeneration system based on somatic embryogenesis for Hedychium muluense R.M. Smith using shoot apex-derived callus. Callus was induced and proliferated on a modified Murashige and Skoog (MS) medium (CIPM) supplemented with 9.05 μM 2-4, D, and 4.6 μM kinetin. Friable callus developed into somatic embryos upon transfer to liquid medium (MS basal salts and Gamborg's vitamins) that was supplemented with 0.6 μM thidiazuron (TDZ) and 8.9 μM 6-benzylaminopurine (BA) and shaken for four weeks. The cultures were then transferred to three Hedychium embryo-development media (HEDM) of varying strengths: HEDM, 1/2 HEDM, and 1/4 HEDM. All three media contained both 0.6 μM TDZ and 8.9 μM BA. Somatic embryo production was higher in full strength HEDM, which produced an average of 103 somatic embryos/explant, half of which could be converted into shoots within a month. Regenerated shoots were readily rooted on a medium supplemented with 0.6 μM 3-indoleacetic acid (IAA) and acclimatized before transfer to the greenhouse. [ABSTRACT FROM AUTHOR]