植物莖往上長(zhǎng)時(shí)表現(xiàn)出負(fù)向地性.The main stems of a plant show negative geotropism as they grow upwards.根系向地性變化可由缺磷等因素所誘導(dǎo), 且存在著一定的遺傳變異性.Root gravitropic responses are adaptive , inheritable traits induced by low phosphorus availability a...