Characterization of a novel pistillody mutant in common wheat.

Pistillody is the homeotic transformation of stamens into pistils or pistil-like structures in wheat. During the development of common wheat near-isogenic line (variety Chinese Spring)carrying Pis1 gene, a pistillody plant was serendipitously observed at field. It was further self-pollinated several generations into a pure pistillody line HTS-1.Pistillodyis of breeding significance as itresultsin more pistils in a floret and even more seed-seting. It can be seen with the naked eye, in which one to three stamens in florets of HTS-1 plants always turn into pistils or pistil-like structures. Light microscopy indicated that some completely transformed stamens show well-developed ovules with normal fertility. Scanning of young spikes with electron microscopy revealed that the homeotic transformation of stamens into pistil-like structures occurred during early-stage stamen development. Dislike those reported before, each plant of HTS-1 showed pistillody trait under normal cultivation conditions. But pistillody degrees varied among the spikelets at different positions of the spike and among the florets of different spikelets. Inheritance analysis of the pistillody trait was carried out by crossing HTS-1 with normal commercial wheat varieties: Mianmai 45, Chuanmai 44, Chuanmai 50, and Chuanmai 28. The F2 and BC1population segregation revealed that the pistillody trait is determined by the interaction of two recessive karyogenes hts1 and hts2. The special genetic base means that this HTS-1 is different from the previously reported lines (cr)-CSdt7BS and N26.