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ARS Home » Southeast Area » Fort Lauderdale, Florida » Invasive Plant Research Laboratory » Research » Publications at this Location » Publication #76769
Title: REPRODUCTIVE POTENTIAL OF THE ABOVEGROUND SEED RESERVOIR OF MELALEUCA QUINQUENERVIA IN SOUTH FLORIDA.

Author
item RAYACHHETRY, MIN - UNIV OF FLORIDA
item Van, Thai
item Center, Ted

Submitted to: Environmental Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/1/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: Melaleuca quinquenervia (Paperbark tree), an invasive weed of Australian origin has invaded sensitive ecosystems in South Florida. It produces and maintains extensive seed reservoirs in the forest canopy. Canopy reservoir provides sustainable seed source for invasion of new areas. Prior understanding of the reproductive potential of these seeds is necessary for evaluating the impact of biocontrol agents. We collected age-cohorts of capsule (fruit) clusters and tested seeds for presence of embryo (fertile), their viability, and germinability by environment types and fruit-age. Seeds the relatively dry environment were more fertile than the seeds from permanently flooded environment. This may be related to abundance and diversity of pollinators in relatively drier environment. Seed viability and germination decreased with the increased fruit age. Some viable seeds showed unknown dormancy which may contribute to persistent soil seed reservoir.

Technical Abstract: Melaleuca quinquenervia produces and maintains extensive aboveground seed reservoirs in the forest canopy. We collected age-cohorts of capsule clusters from dry, seasonally flooded, and permanently flooded habitats. Seeds from each cluster were evaluated for fill, viability, and germination after being soaked for 10 days in sterile deionized water and/or 2,3,5,-triphenol tetrazolium chloride stain. Evaluations were conducted by microscopic inspection. Most (85 percent) canopy- stored seeds were empty and nonfertile; seed fill varied from 10 percent at permanently flooded to 16 percent in dry habitats. Cluster age affected both viability and germination. Viability of filled seeds and germination of viable seeds were both maximal in middle-aged clusters (Clusters II to IV) then decreased in older clusters (Cluster VII). A small portion of viable seeds did not germinate and may have been dormant. These dormant seeds may, upon release from the capsules, augment persistent soil seed banks that germinate only under unknown circumstances.