The researches about the classification and identification of their species and varieties have provided an early, subservient and selective index for breeding work.

其种间或品种间的分类鉴定和亲缘关系的研究为育种工作提供了一个早期的、辅助的、选择性的指标。

youdao

There were higher selective in light gazing because of the sufficient food supply and less selective in heavy grazing due to less plant species.

轻度放牧区食物充足，绵羊的选择性采食行为较明显，重度放牧区植物稀疏，食物匮乏；

youdao

Rice medium was used to identify the species groups of genus of Fusarium fungi selected by Komada or No. 1 selective culture medium from soil.

选择镰刀菌用驹田或植选1号培养基，在米饭培养基上划分镰刀菌种群，用试管法或盆栽作致病性测定，以检测土壤中棉花枯萎病致病菌。

youdao

At one time or another, indigenous people in tropical Africa and South America knew how to cultivate and prepare nutritious food by selective breeding of as many as 30, 000 species of plants.

ECONOMIST: Growth and geography

This lack of grandchildren should be an enormous selective pressure on flycatchers to pick a mate of the same species.

ECONOMIST: Evolution