Usually the more unlike the parents are the more hybrid vigor is released, but the effect diminishes in subsequent gener通常，亲本越不相似，产生的杂种优势越强，但这种优势使下一代的隐性纯合子的出现机率更多。
Study on Esterase Isozyme and Inter_specific Relationship and Hybrid Vigor in Silkworm(Bombyx mori)家蚕酯酶同工酶与品种亲缘关系及杂种优势的研究