栝楼初生根静止中心的研究

用~3H-胸腺嘧啶核苷处理栝楼(Trichosanthes kirilowii Maxim.)初生根不同生长阶段的根尖,并用放射自显影技术测定根尖静止中心的存在。在各个生长阶段中,静止中心缺乏标记的细胞核。在生长过程中,静止中心的体积发生变化;静止中心所在部位也有发展。最初仅占中柱顶端和皮层顶端最内层的部分。当根长大时;静止中心扩大到皮层比较靠外的部分,但静止中心从来不越过次生冠轴原始细胞。

QUIESCENT CENTER OF PRIMARY ROOT OF TRICHOSANTHES KIRILOWII MAXIM.

Primary roots at various stages of Trichosanthes kirilowii Maxim,were treated with 3H-thymidine and a number of autoradiographic sections were made to determine the presence of a quiescent center.Cells outside the quiescent center gave a sharp nuclear autoradiograph,which cells inside the quiescent center gave nearly no labeled nuclei.The size of quiescent center increased during growth.At early stages the quiescent center only occupied the apical portion of the central cylinder and the innermost part of the apical portion of the cortex.During the growth of the roots,the outer part of the apical portion of the cortex were also included.However,the quiescent center never crossed the line between the central cylinder apical initials and the secondary columella initials.Primary roots at various stages of Trichosanthes kirilowii Maxim,were treated with 3H-thymidine and a number of autoradiographic sections were made to determine the presence of a quiescent center.Cells outside the quiescent center gave a sharp nuclear autoradiograph,which cells inside the quiescent center gave nearly no labeled nuclei.The size of quiescent center increased during growth.At early stages the quiescent center only occupied the apical portion of the central cylinder and the innermost part of the apical portion of the cortex.During the growth of the roots,the outer part of the apical portion of the cortex were also included.However,the quiescent center never crossed the line between the central cylinder apical initials and the secondary columella initials.