The ancestors of plants were photosynthetic single-celled organisms that gave rise to plants presumably lacked true roots, stems, leaves, and complex reproductive structures such as flowers.
2
矮化突变体在阐明植物茎的生长发育调节机制和植物育种中具有十分重要的作用。
Dwarf mutant has very important effect on elucidating regulation mechanism of stem development and plant breeding.
3
绿色植物叶进行光合作用制造有机物,通过茎的韧皮部向下运输供给根的需要。
The organic matters were produced through photosynthesis by the leaves of the green plants and were transported down to meet the need of root through the bast of the stem.