Proc. 2nd IntI. Symp. Buckwheat Miyazaki BUCKWHEAT RESEARCH 1 9 8 3 Amino Acid Composition of Five Buckwheat Cultivars

A new buckwheat cultivar was developed by Labolatory of Plant Breeding, Faculty of Agriculture, Miyazaki University. And it was resistered as the name of Miyazakiootsubu ( Nagatomo et al. 1982). Miyazakiootsubu was selected from an induced autotetraploid line originated in diploid variety Miyazaki-zairai. There are some studies on the comparison of protein contents and amino acid compositions between diploid and tetraploid ( Javornik 1980, Kubiczek 1980) but ther is no report on those of Miyazakiootsubu. We investigated the protein contents and amino acid compositions of Miyazakiootsubu and four diploid cultivars, Miyazaki-zairai, Sando-soba, Hashikamiwase and Shinano-ichigou. Crude protein was determined by Kjeldahl method and amino acid composition was determined by High Performance Liquid Chromatography. o-Phthalaldehyde method was used for detection of amino acid instead of conventional ninhydrine method and the detection limit of this analysis was 50 pico mole ( Roth 1971). As a result of analysis of varience, small, but statistically significant differences in the contents of aspartic acid, threonin, glycine, alanine, cystine, valine, methionine, isoleucine, leucine, tyrosine