决明属牧草新品种的选育

通过有性杂交和辐射处理5个决明属牧草品种进行新品种选育研究。结果表明：圆叶决明种内杂交取得成功；圆叶决明和羽叶决明种间杂交，以圆叶决明为母本的杂交组合已有结荚后代；有性杂交筛选到6株农艺性状已基本稳定的生物量大、分枝多的杂交株系后代。辐射育种筛选到5个品质优良的新品系，其中2个86134品种辐射变异后．后代品系的茎长和生物量有明显提高，茎叶比则呈明显下降；2个92985品种辐射变异后，后代品系的粗蛋白含量有明显提高；1个34721品种辐射后，后代品系的Ca含量有明显提高。

Breeding and Selection of New Cultivars of Chamaecrista spp.

Five accessions of Chamaecrista spp. were used for breeding and selection of new cultivars by crossing and irradiation treatment. The results showed that Chamaecrista rotundifolia succeeded in intraspecific crossing. The interspecific crossing between C. rotundifolia and C.nictitan with C.rotundifolia as female parent succeeded and produced its progeny. Six individual plants of the progeny of the crosses were selected to have larger biomasses and more branches and stable agronomic characters. By irradiation breeding 5 desirable mutants were selected from the 5 accessions of Chamaecrista spp. Of the 5 mutants 2 were selected horn the progeny of mutants of C.rotundifolia accession 86134 and had obviously higher stem length and biomass but a lower ratio of stem to leaf; 2 were selected from the progeny of mutants of C. rotundifolia accession 92985 and had notably higher crude protein content; and 1 was selected from the progeny of mutants of C.rotundifolia accession 34721 and contained evidently higher calcium.