春播二条オオムギにおける裂皮粒歩合のQTL解析

The exposure of the caryopsis through lemma and palea is called 'hull-cracked grain', which lowers the germinability and grade of malting barley. To breed new varieties with a low occurence of hull-cracked grains,quantitative trait loci(QTL) analysis was conducted using 146 doubled haploid lincs derived from Harrington ×　TR306.Interval mapping analysis revealed three significant QTLs on chromosomes 3H,5H and 7H. About 37% of the variation of the expressvity of hull-cracked grains was explained by these three QTLs in a spikelet-thinning condition where 1/4 of the spikelets were thinned at the flowering time. On the contraty the QTL on 5H was silent in normal or non-treated condition and 23% of the variation was determined by the QTLs on 3H and 7H. Some of the QTLs detected here had a pleiotropic effect on the grain size.

Harrington×TR306に由来する倍加半数体146系統およびその両親を北海道網走市で春播条件で栽培し、頴花の1/4を間引いた摘粒地区と無処理区で裂皮粒歩合を調査し、interval mappingによって裂皮粒歩合を支配するQTL解析を行った。両親の裂皮粒歩合は極めて低かったが、裂皮粒歩合の高い系統の超越分離が認められた。無処理区では3Hと7Hに有意なQTLが見出され、これらによって変異の約23％が説明できた。摘粒区ではこの2つに加えて5Hにも有意なQTLが見出され、これらによって変異の37％が説明できた。これらの3つのQTLのうち2つは粒大を支配するQTLと同座と見られた。