Aquatic Plant Control Research Program: Review of Senescence as an Important Factor Determining the Relationship Among Aquatic Plants, Their Epiphytes, and Pathogens
Abstract
This report is a review of literature on senescence and relationships between senescence and microorganisms in aquatic plants. The first part of the report summarizes the main facts regarding senescence. Senescence is an important and not very well-understood stage in the life cycle of a plant. It is controlled by internal and external (environmental) factors. The precise mechanism of senescence induction is not known, but, in general, the initiation of senescence involves an imbalance in the relative levels of growth hormones. The change in hormone status can be internal factors or environmental stimuli. The second part of the report describes epiphytic microorganisms on aquatic plants: Aquatic macrophytes often serve as a substratum for epiphytic microorganisms, namely algae, bacteria, and fungi. The amount and diversity epiphytic micro-organisms generally increase with the age of their host, mainly due to the increasing amount of organic matter excreted by the aging host plant. Few viruses were reported from aquatic plants. Viruses may offer an alternative for biological control, but at this point data are insufficient to even consider this possibility. Two main points can be made from the literature search: (a) senescence is a process that can be induced by changing the environmental conditions, and (b) plants in the senescent stage are more susceptible to pathogens than young or mature but nonsenescent plants. Keywords: Aquatic plants; Epiphytes; Pathogens; Biological weed control.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1989
- Accession Number
- ADA208580
Entities
People
- Eliska Rejmankova
Organizations
- University of California, Davis