常見例句雙語例句Pollen grain is mainly 2-celled type when shed, occasionally 3-celled type, and has three apertures.成熟花粉多爲(wèi)2-細(xì)胞型,偶見3-細(xì)胞型,具三萌發(fā)孔。d.wanfangdata.com.cnThe characteristics of pollen grain are related with the distribution of Gnetum and classified system of subgenus.買麻藤屬植物孢粉學(xué)特征與地理分佈及屬下分類系統(tǒng)有一定的關(guān)系。The ubisch bodies which appeared on the inner tangential wall of the tapetum at the time of microspore wall formation are partially remain on the surface of matured pollen grain.小孢子壁形成時(shí)開始在羢氈層內(nèi)切線壁出現(xiàn)的球狀躰到花粉粒成熟時(shí)仍有一部分附著於花粉粒表麪。 返回 pollen grain