Architecture of remnant trees influences native woody plant recruitment in abandoned Hawaiian pastures

Microshoot and callus cultures of Cornus florida (flowering dogwood), which were grown on woody plant medium amended with BA, were inoculated with Microsphaera pulchra (an obligate plant parasite) by gently shaking infected leaves bearing numerous conidia over the tissue. Culture dishes were sealed with parafilm and incubated at 24 °C with 25 mol·m–2·s–1 provided by cool fluorescent bulbs for 15 h. Cultures were examined with a dissecting scope every 24 h and cultures transferred when contaminating fungi were present. Specimens were prepared light microscopy and SEM. The fungus infected individual callus cells, but did not sporulate. In contrast, powdery mildew was well-established (both primary and secondary hyphae) in 70% of the microshoot cultures after 6 days and sporulated on 20% by 7 to 8 days. The cellular relationship between host and pathogen in vitro was similar to that found in greenhouse-grown plants. This technique has possible applications in maintaining fungal culture collections and studying host–pathogen relationships under more stringently controlled conditions.

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Vegetative Propagation of Woody Ornamentals Through Forcing of Epicormic Shoots

HortScience ◽

10.21273/hortsci.33.3.503c ◽

1998 ◽

Vol 33 (3) ◽

pp. 503c-503

Author(s):

Paul H. Henry ◽

John E. Preece

Keyword(s):

Plant Material ◽

Woody Plant ◽

Clonal Plant ◽

Light Regime ◽

Moisture Regime ◽

Stem Cuttings ◽

Shrub Species ◽

Woody Ornamentals ◽

Ornamental Tree ◽

Environmental Light

A propagation method is being developed that allows softwood shoots to be generated from stem sections of dormant woody plant species. These shoots, forced in the greenhouse during the winter, are subsequently collected and processed as softwood stem cuttings to produce clonal plant material. Many species in the nursery industry can only be propagated using softwood cuttings, and this technique allows propagation of these species to be initiated several months earlier than what is typically possible. Current studies involve expanded screening of ornamental tree and shrub species to determine if commercial production using this technique is feasible. Results demonstrate that many species may be propagated using this method, but that some species are more prolific than others with respect to number of softwood shoots produced. Additional studies are currently in progress to determine the environmental (light regime, moisture regime) and cultural (type of media) conditions that are optimal when producing clonal plant material via this technique.

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