The quiescent center and primary vascular tissue pattern formation in cultured roots of Zea

Abstract

Roots of Zea mays cv. Kelvedon 33 were cultured in nutrient media supplemented with varying concentrations of sucrose. In some instances an individual root was grown successively for periods of time in several different concentrations of sucrose. From this work it was shown that the complexity of the vascular patterns in cultured roots as well as the size of the quiescent center could be manipulated by altering the levels of sucrose in the nutrient medium. The simplest vascular patterns were found in roots in which the quiescent center was most reduced in size. In roots with relatively larger quiescent centers more complex vascular patterns were observed. Based on these studies a proposal is advanced concerning the relationship between the quiescent center and the initiation and maintenance of primary vascular tissue patterns in roots.