| 释义 |
topcross
\ˈ ̷ ̷ˌ ̷ ̷\ noun
Etymology: top (I) + cross
1. : a cross in which usually male superior or purebred individuals are mated with inferior stock to improve the average quality of the progeny; also : the product of such a cross — compare grade 5
2. : a cross between an inbred line and a random-bred variety or strain of the same organism (as one between a strictly inbred line and a horticultural variety of maize); also : the first generation hybrid that is produced by such a cross — compare single cross |