REGENERATION OF ACTIVE ROOT MERISTEMS IN VITRO BY HYPOCOTYL SECTIONS FROM DORMANT PINUS LAMBERTIANA EMBRYOS
REGENERATION OF ACTIVE ROOT MERISTEMS IN VITRO BY HYPOCOTYL SECTIONS FROM DORMANT PINUS LAMBERTIANA EMBRYOS
复制标题
休眠松胚胎下胚轴切片体外活性根分生组织的再生
作者：
M. Greenwood;G. Berlyn
* 产生的根总数减去未能去除原分化的预期值。产生3毫米切片的根，在其他几个实验中做同样的事情。还有较小比例的较短根被再生。使用 2 毫米和 3 毫米切片获得的一些结果如表 I 所示。2 毫米切片产生根所需的时间更长，这可能表明下胚轴片段再生根的能力从根分生组织区域向子叶下降。然而，当使用 2 毫米和 3 分钟的切片时，在根系的同一位置进行切割，3 毫米的切片更容易再生根。更大质量的组织似乎稍微加速了再生。进行了与上述类似的另一个实验，但倒置培养物中切片的方向相反。将 3 分钟切片移出，根端置于琼脂中，子叶端朝下置于空气中。如上所述进行切割。只有一次产生了根；它起源于琼脂部分的根端。这是这些胚胎下胚轴中根产生的极性的明确证据。在一种情况下，针开始从子叶和顶端分生蛋白被去除的切割组织中生长出来。尽管仅实现过一次，但胚胎芽分生组织区域也有可能具有再生能力。无论如何，下胚轴部分在根再生方面表现出明显的极性。
* Total number of roots produced minus expected value iroln failure to remove promeristern. produce roots as for 3-mm sections to do the same in several other experiments. Also a smaller percentage of shorter roots was regenerated. Some of the results obtained using 2-mm and 3-mm sections are shown in Table I. That it took longer for the 2-mm sections to produce roots may indicate that the capacity for a hypocotyl segment to regenerate a root decreases from the root meristem region towards the cotyledons. I-Iowever, when 2-mm and 3-min sections are employed, with cuts in the same place with regard to the root n~ eristem, the 3-mm sections regenerate roots more readily. A greater mass of tissue present seems to hasten regeneration slightly. Another experiment similar to those above was carried out, but the orientation of the sections in the inverted cultures was reversed. The 3-min sections were explanted with the root end in agar and the cotyledon end pointed downwards in air. Cuts were made as described above. In only one instance was a root produced; it originated from the root end of the section in the agar. This is definite evidence of polarity with regard to root production in these embryonic hypocotyls. In one case needles began to grow from the cut tissue where the cotyledons and apical meristein were removed. It is possible, though it has been attained only once, that the embryonic shoot meristematic region also has regenerative capacities. In any case, there is a distinct polarity shown by the hypocotyl sections with regard to root regeneration.