1. CW 39S7 is a synthetic variety with 470 parent plants which were selected sequentially for resistance to Phytophthora root rot and Anthracnose (race 1). Parent plants were selected from crosses between selections from four year old California yield trials and various populations developed by a combination of phenotypic recurrent selection and strain crossing with selection for one or more of the following pests: Fusarium wilt, Verticillium wilt, anthracnose (race 1), Phytophthora root rot, blue alfalfa aphid, and spotted alfalfa aphid. Parentage of CW 3957 traces to the following germplasm sources: Altiva, CW 2820, DK 189, Mecca, CW 2817, UC 332, and CW 2818. Approximate germplasm source contributions are as follows: M.varia (2%), Turkistan (6%), Flemish (2%), Chilean (4%), Peruvian (2%), Indian (23%), African (52%), and Unknown (9%).
2. CW 3957 is adapted to the Southwestern U.S. and is intended for use in the southwestern U.S., Mexico, and Argentina. CW 3957 has been tested in California and Mexico.
3. CW 3957 is a very non-dormant variety with fall dormancy similar to CUF 101. Flower color observed in the Syn.2 generation is approximately 100% purple.
4. CW 39S7 has high resistance to Fusarium wilt, stem nematode, spotted alfalfa aphid, blue alfalfa aphid, and pea aphid, resistance to anthracnose (race 1) and Phytophthora root rot, and moderate resistance to Verticillium wilt. Reaction to bacterial wilt, Aphanomyces root rot (race 1), and root knot nematode has not been adequately tested.
5. Seed increase of CW 3957 is on a limited generation basis with one generation of breeder and two generations of the foundation, and certified seed classes. Breeder (Syn.l), foundation (Syn.2 or Syn.3), and certified (Syn.3 or Syn.4) classes will be recognized. Production of Syn.3 foundation seed requires the consent of the breeder. Breeder seed was produced under cage isolation at Woodland, California in 1993. Sufficient foundation seed for the projected life of the variety will be maintained by Cal/West Seeds. Stands of foundation and certified seed fields are limited to 3and 6 years, respectively.
6. Certified seed of CW 3957 will be available in 1997.
7. No decision has been made regarding Plant Variety Protection.
8. This information can be forwarded to the PVP office.
9. Variety Name: . Date submitted: 12/1/96. Experimental Designation: CW 3957
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