Submitted to: Plant Genetic Resources International Board Newsletter
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/16/1998
Publication Date: N/A
Interpretive Summary: Amaranths are cultivated for their nutritious seeds, which improve the nutritional quality of baked goods and cereals, and as a leafy green vegetable. The USDA-ARS's North Central Regional Plant Introduction Station (NCRPIS) in Ames, Iowa maintains more that 3,000 amaranth varieties in its genebank. NCRPIS staff members must produce pure seeds of these 3,000 varieties, but many of them flower too late in the growing season to mature their seeds outdoors in Iowa. In response, NCRPIS staff members developed a technique whereby amaranth plants are grown for seed production under plastic tents in a greenhouse, during the late fall and winter when greenhouse space is readily available. The procedure generally yields from 40,000 to 120,000 seeds from 100 parent plants. To help determine the effectiveness of this procedure, both cross-pollination rates within tents and contamination rates from pollen outside the tents were measured. The frequency of cross-pollination was within an acceptable range, and the frequency of contamination was extremely low. This technique has had an important, positive impact by providing a relatively simple, low-cost method of increasing the rate of amaranth seed regeneration, so that these plants are more quickly available for research world-wide. Managers at other genebanks can also benefit by adapting this system to increase the efficiency of their seed multiplication programs.
Technical Abstract: Amaranthus germplasm is efficiently regenerated in plastic tents within greenhouses. This protocol involves the cultivation of 100 plant populations in 0.8 m*2* x 1 m tall tents, and generally yields 40,000 to 120,000 seeds about three months after planting. Experiments were performed to test the effectiveness of pollination control by isolating four monoecious Amaranthus species in these plastic tents. The estimated frequency of pollen contamination between tents was 0.01%. The estimated frequency of cross pollination within tents was 3.9%.