| Alfalfa (Medicago sativa L.) breeders are faced with the problem of incorporating an increasing number of desirable traits into cultivars. Conventional breeding methods are limited in their ability to accomplish this in a limited period of time. Strain-crossing is proposed as a rapid alternative to assist in reaching these goals. The basic assumption is that strain-cross progeny will perform intermediate to the parents. By careful selection of parental material for complementary characteristics, pest resistance and fall dormancy could be easily manipulated. The objectives of this study were to determine the predictability of midparent values for insect resistance, disease resistance, nematode resistance, fall dormancy, and forage yield in crosses of diverse genetic materials.;Eighty-five percent of the evaluations produced the expected midparent values. Significant deviations that occurred were generally in a favorable direction, except for pea aphid and spotted alfalfa aphid resistance. Fall dormancy was the least predictable, especially when parental material was widely different. Progeny deviations for fall dormancy were toward the non-dormant parent.;It was concluded that predictability of strain-crossing to produce midparent or better values was approximately 90 percent.;Strain-crosses were made in the field with isolation provided by screewire cages, the pollination by honeybees. Equal amounts of seed from the parents were bulked to form the strain-cross. The resulting progeny were evaluated for resistance to three insects, four diseases, one nematode, fall dormancy, and forage yield using standardized procedures. |
