BNEL29c6 Barley EST endosperm library Hordeum vulgare subsp. vulgare cDNA clone BNEL29c6 5' similar to Triticum aestivum subsp. spelta partial Glu-B1-1 gene for high-molecular-weight glutenin subunit, exon 1, specimen voucher Gattersleben TRI 17511, mRNA sequence