Ellen Jackson has had 3,209 starters in her 27 years as a trainer, but her first entrant in a graded stakes race comes Saturday when the speedy Many Roses runs in the Grade 3, $100,000 San Francisco Mile at Golden Gate Fields. Jackson’s situation is by design, because she also operates a successful breeding operation — Victory Rose Thoroughbreds in Vacaville — and she funds it by selling nearly every horse she raises. In the case of Many Roses, she owns the 4-year-old gelding with Jerry and Margaret Martin. “My partners want the fun of running the horse and I’m happy to do that,” Jackson said. Many Roses has won four of 11 starts, and although Saturday’s race will be his first in a stakes event, he proved he belonged by coming within a half-length of beating four-time stakes winner G.