Description:
WISFAL-3 descends from Medicago falcata PI 172980, PI 251205, PI 251830, and PI 253443 reported in Crop Sci. 15 :889, 1975. These PI entries were mainly diploids but contained occasional tetraploid plants. Pure M. falcata tetraploids with yellow flower color and M. falcata pod shape were selected for use. The tetraploids in diploid populations likely arose by union of restitution gametes. Tetraploids were identified in the field by larger plant and leaf size, and confirmed in the greenhouse by fertility in crosses with alfalfa, and by chromosome count. Initial tetraploid seed for WISFAL-3 was produced by hand intercrosses of the above PI plants in the greenhouse in 1975. This tetraploid seed, and seed from the diploid plant introductions reported in Crop Sci. 15:889, 1975, were planted in long term nurseries for natural selection for adaptation to Wisconsin, and the North Central Region. The first nursery was at Arlington, WI, from 1977-1982; next at West Madison Area Research Station (WMARS), from 1984-1989. Nurseries were planted in rows, one meter apart, with rows alternating diploid and tetraploid, to allow crossing of diploids and tetraploids, with the potential of new tetraploids by restitution gametes from the diploids. Nurseries were managed as hay fields, never irrigated, never sprayed, until the last year, when the second crop set flower, and set seed by open pollination by native bees. The process was slow recurrent selection for adaptation/naturalization. In 1990, a sample of tetraploid seed was planted and allowed to flower, to identify plants with yellow flowers, to use for hand pollination seed increase in the winter greenhouse. Finally, this seed was further increased at Fresno, CA, in a 20X20 foot cage, in 1992. This is the WISFAL-3 seed submitted.