启动导管 meaning in English

pilot manifold

The results showed that the vessel element did n ' t differentiate after the seeds had imbibied for 6 hours ; 6 hours after seeds germination , two loci ? ne below the middle portion of the cotyledon and the other in the lower portion of cotyledon - node zone ( cnz ) initiated the differentiation of vessel element simultaneously , then elongated towards the cotyledonary apex and hypocotyl - root region respectively ; eventually the two promoter loci began to interconnect through vessel elements
结果表明：种子吸涨6h ，未有导管分子的分化；种子萌发后6小时期间，自子叶中部偏下方和子叶节区下部的两个位点同时启动导管分子的分化，并分别向子叶叶尖和下胚轴-根的方向延伸；尔后，在发生两个启动位点之间发生导管分子的连接。