Publication Date
1985
Location
Kyoto Japan
Description
Research is underway to develop tetraploid cultivars of red clover (Trifolium pratense L.) for use in the United States that will be more resistant and higher yielding than presently used diploid cultivars. Cultivars have been produced by use of colchicine, nitrous oxide, and unreduced gametes (2X-4X and 4X-2X crosses). Nitrous oxide treatments have produced up to 71 percent tetraploids which is much higher than that from colchicine (about 4 percent). This nitrous-oxide developed tetraploids population from the cultivar 'Kenstar' has been used as one parent in 2X-4X and 4X-2X crosses. The former yielded a high percentage of tetraploids whereas the latter produced mostly triploids and few tetraploids. Field trials of tetraploid populations produced by nitrous oxide ranged in yield from 57 to 92 percent of the yield of the diploid Kenstar. The lower yields of the tetraploid are attributed to inbreeding depression from chemical doubling as has been shown in alfalfa (Medicago sativa L.). The unreduced gamete tetraploid population (2X-4X) crosses served to widen the genetic base by introducing eight clones from four divergent sources. Yield of the new tetraploid ranged from 69-84 percent of the diploid under field conditions. Research is underway to utilize 4X-2X and additional 2X-4X crosses to widen the genetic base and further maximize heterozygosity so that the potential yield and persistence of autotetraploid red clover may be realized under USA conditions.
Citation
Taylor, N L. and Wiseman, E O., "Methodology and Breeding of Tetraploid Red Clover" (1985). IGC Proceedings (1985-2023). 20.
(URL: https://uknowledge.uky.edu/igc/1985/ses2/20)
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Methodology and Breeding of Tetraploid Red Clover
Kyoto Japan
Research is underway to develop tetraploid cultivars of red clover (Trifolium pratense L.) for use in the United States that will be more resistant and higher yielding than presently used diploid cultivars. Cultivars have been produced by use of colchicine, nitrous oxide, and unreduced gametes (2X-4X and 4X-2X crosses). Nitrous oxide treatments have produced up to 71 percent tetraploids which is much higher than that from colchicine (about 4 percent). This nitrous-oxide developed tetraploids population from the cultivar 'Kenstar' has been used as one parent in 2X-4X and 4X-2X crosses. The former yielded a high percentage of tetraploids whereas the latter produced mostly triploids and few tetraploids. Field trials of tetraploid populations produced by nitrous oxide ranged in yield from 57 to 92 percent of the yield of the diploid Kenstar. The lower yields of the tetraploid are attributed to inbreeding depression from chemical doubling as has been shown in alfalfa (Medicago sativa L.). The unreduced gamete tetraploid population (2X-4X) crosses served to widen the genetic base by introducing eight clones from four divergent sources. Yield of the new tetraploid ranged from 69-84 percent of the diploid under field conditions. Research is underway to utilize 4X-2X and additional 2X-4X crosses to widen the genetic base and further maximize heterozygosity so that the potential yield and persistence of autotetraploid red clover may be realized under USA conditions.
