| | Micropropagation is a process of generating many plantlets from a small amount of plant tissue in a controlled laboratory environment. (Photo by Prasanta K. Subudhi) |
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Prasanta K. Subudhi, Niranjan Baisakh, Diptimayee Sahoo, Stephen A. Harrison, Michael D. Materne and Herry S. Utomo
Sea oats is a valuable plant species for coastal restoration. Large numbers of sea oat plants are needed to stabilize dunes as a part of the ongoing effort to save our wetlands and coastal ecosystems. Development of micropropagation techniques by LSU AgCenter researchers will add a new dimension to the coastal restoration effort and help ensure a steady supply of sea oat plants throughout the year.
Sea oats (Uniola paniculata) is a native dune plant commonly pictured on tourism pamphlets for beach resorts. This grass species is frequently used for dune restoration and vegetative stabilization projects throughout its native range in the United States. It is a semitropical, perennial grass noted for excellent sandholding ability and tolerance to drought, inundation by sea water, salt spray, strong winds and tropical storms.
Sea oats has a deep, fibrous root system that allows it to thrive in sandy environments with minimal nutrition and high sand temperature. It traps sands and builds dunes that provide protection to coastal ecosystems. The frequency of damaging tropical storms has increased in recent years, and sea oats plants help restore damaged coastal areas. LSU AgCenter researchers have developed sea oats lines for use in restoration activities and have developed a means to masspropagate these elite lines.
Louisiana beaches and dunes are characterized by low elevation and frequent over-washing and erosion. Although this environment is quite different from the typical high dunes where sea oats plants dominate, there are sea oats lines that grow on the Louisiana coast. A primary barrier to large-scale use of sea oats for coastal reclamation in Louisiana is the limited seed production of adapted types and native populations. In comparison to other states in the southeastern region of the United States, seed set in sea oats populations of Louisiana is very low and, consequently, most of the existing natural stands of sea oats on barrier islands have been lost over time. Thus, the development of micropropagation technology is essential for large-scale use of sea oats for coastal restoration.
Planting seeds is the major method of propagation in most plants. Because seeds are the result of sexual reproduction and recombination of genes, plants resulting from seeds may differ from their parents in many attributes. Plants that are asexually propagated from vegetative plant parts such as roots, stems and leaves are usually identical to their parent since sexual recombination does not occur.
Micropropagation is an asexual propagation method in which tissue culture techniques (growing plants in test tubes) are applied in an aseptic (away from disease-producing microorganisms) environment to generate many identical plantlets. For those plant species that do not produce seeds or do not regenerate plants from vegetative tissues easily, micropropagation is a suitable alternative. It also has been an effective means of generating virus- and disease-free plants in large numbers (sugarcane, for example) and for the development of novel plants through genetic modification.
Micropropagation is a process of generating many plantlets from a small amount of plant tissue in a controlled laboratory environment. The process involves a multi-step procedure starting with selection and excision of plant parts (explants) followed by sterilization and growing in appropriate media containing all necessary nutrients for plant growth. Media composition is manipulated with different doses of growth hormones for shoot proliferation or rooting. Since microbial contamination is a major problem in tissue culture procedures, utmost care is taken to work in an absolutely contaminant- free environment.
LSU AgCenter research on tissue culture response of different sea oats lines is ongoing. We estimate that from a single explant, 100-200 plants can be generated within five to six months. Because there is concern about variation during tissue culture process, we are determining the genetic variation among these tissue culture-propagated plants using DNA fingerprinting.
We are concurrently trying to establish a protocol to generate multiple shoots, using mature plants as a source. This would allow production of large numbers of plants identical to an elite sea oats plant maintained in a nursery bed. Although we have identified a few candidate recipes for a protocol, research is still under way to identify the best concentration and combination of hormones to induce shoot proliferation in the least amount of time. Once the multiple shoots are generated, shoots can then be split and multiplied further to generate more seedlings.
Prasanta K. Subudhi, Assistant Professor; Niranjan Baisakh, Postdoctoral Researcher; Diptimayee Sahoo, Graduate Student; Stephen A. Harrison, Professor; Michael D. Materne, Instructor, School of Plant, Environmental & Soil Sciences, LSU AgCenter, Baton Rouge, La.; and Herry S. Utomo, Assistant Professor, Rice Research Station, Crowley, La.
(This article was published in the spring 2007 issue of Louisiana Agriculture.) |