germ layer是什么意思

用法例句

from 7-day-old seedlings were c ultured on inducing nutrient medium to study on establishment of regeneration sy stem of maize embryo leaf of inbred lines in northeast.

取不同基因型的东北主栽玉米自交系胚叶3mm接种在诱导培养基上,研究东北主载的玉米胚叶再生体系的建立。