CHROMOSOME LOCATION OF THE GENE FOR BRITTLE RACHIS IN THE TIBETAN WEEDRACE OF COMMON WHEAT

The brittle rachis of the Tibetan weedrace (Triticum aestivum var. tib etanum) was found to be governed by a single dominant gene on the shor t arm of chromosome 3D. The new brittle rachis gene was designated Br- 1. This study also discovered that the type of disarticulation is gove rned by many genes that may differ from brittle rachis genes. In other words, the same brittle rachis gene may exhibit various types of disa rticulation in various genetic backgrounds. So, after the brittle rach is gene (barrel type) in Aegilops tauschii entered hexaploid wheat thr ough the amphidiploid path, it might exhibit the wedge type of disarti culation.