将杂种杨树(Populus nigra var.betulifolia×P.trichocarpe)NE299叶主脉用振动切片机横切成400μm或800μm的薄切片,培养在附加0.2mg/L BA和0.01mg/L NAA的木本植物培养基上。培养后,位于主脉维管束两侧中上部的维管束鞘薄壁细胞...将杂种杨树(Populus nigra var.betulifolia×P.trichocarpe)NE299叶主脉用振动切片机横切成400μm或800μm的薄切片,培养在附加0.2mg/L BA和0.01mg/L NAA的木本植物培养基上。培养后,位于主脉维管束两侧中上部的维管束鞘薄壁细胞首先启动分裂。几乎同时,与其邻接的一些栅栏组织细胞也分裂,并很快形成胚性分生细胞团。主脉的愈伤组织主要由维管束鞘薄壁细胞,以及与其邻接的一些栅栏组织细胞和韧皮部的薄壁细胞分裂而来。不定芽通常发生在愈伤组织的周边区,也可以起源于维管组织结节(vascular nodules)周围的形成层状细胞。侧脉的维管束鞘细胞分裂活动很强,可不经愈伤组织直接长成不定芽。杨树叶主脉处的维管束鞘薄壁细胞在与叶肉组织相邻接的细胞中,通常含有少量较小的叶绿体,而位于背腹面的细胞中含有贮藏的淀粉。对形态发生的特定部位及其细胞进行了讨论。展开更多
Up to now, male germ units (MGUs)have been found in many angiosperms. This is an important advance in the studies of reproductive biology. However, there is little information on the interaction (the penetration and e...Up to now, male germ units (MGUs)have been found in many angiosperms. This is an important advance in the studies of reproductive biology. However, there is little information on the interaction (the penetration and exchange of substances) between vegetative nucleus (VN) and generative cell (GC) or sperm cells within MGUs. If there exists, what kind of substance Will it be and how will it work, and what physiological function will it have? This is a very important problem which needs to be solved as soon as possible.展开更多
文摘Up to now, male germ units (MGUs)have been found in many angiosperms. This is an important advance in the studies of reproductive biology. However, there is little information on the interaction (the penetration and exchange of substances) between vegetative nucleus (VN) and generative cell (GC) or sperm cells within MGUs. If there exists, what kind of substance Will it be and how will it work, and what physiological function will it have? This is a very important problem which needs to be solved as soon as possible.
