WL 450
WATERMAN-LOOMIS COMPANY, BAKERSFIELD, CALIFORNIA
1. Seedling inoculation with stem nematode commenced in late 1964 using selected clones from WL 504, Flemish varieties and PI 141462 for progeny testing. Six thousand seedlings were screened which resulted in 708 tolerant or resistant plants of which 1% traces to PI 141462, 2.4% to Flemish and 96.6% to WL 504. Twenty resistant survivors selected for type and disease resistance were crossed with selected plants related to WL 504 in an isolated nursery. Seed was harvested from each of the stem nematode resistant plants and 500 seedling of each plant were reinoculated. About 400 selected survivors were planted in an isolated cage for observation, rogueing and seed production. Thirty-one clones showing 35% or more stem nematode resistance in progeny testing were recombined in 1967 to develop WL 450.
2. WL 450 is adapted to portions of the Southwest and other related areas where stem nematode is a problem. It has been tested in California, Arizona, Minnesota, Southern Nevada, Southern Utah and North Carolina. It is intended for hay, silage and dehydration.
3. Flower color is predominately purple to light purple, growth habit upright and moderately uniform, resistant to spotted alfalfa aphid of unknown local biotypes of Kern County, California and downy mildew, moderately resistant to the pea aphid and tolerant to Southern anthracnose and Leptosphaeria leaf spot.
4. Breeder seed is the Syn. 2 of the 31 clones selected for 35% or more stem nematode resistance. The Syn. 1 seed was planted in Kern County, California producing 284 pounds of Breeder seed which is maintained in temperature and humidity controlled storage. WL 450 shall be in the limited generation sequence with one generation each of Breeder, Foundation and Certified seed classes. Certified seed shall be the first generation increase of Breeder or Foundation seed.
5. 1973-1974.
6. No.