J Integr Plant Biol. ›› 1979, Vol. 21 ›› Issue (2): -.
• Research Articles •
Wang Kai-ji, Zhang Pi-fang, Ni De-xiang, Zhu Xiu-zhu, Yang Wei-qin and Bao Zi-hua
The development of callus in vitro was investigated using the isolated explants from the autumn twig of Olea europaea. The callus developed on the cut surface of the stem-segment originate, d from the living cells of different tissues. Two distinct morphological types of the calli were observed. The highly friable callus was generally obtained while a non-friable form might develop occasionally. The change from one form to another was achieved by changing the level of NAA in the culture medium. These results obtainecl from above may be used to explain the possible role of the auxin playing a part in the form of callus. However, another distinct type of the callus in addition was also obtained in the same culture medium. This type of the callus developed in the form of a knob. It originated from cortical parenchyma cells distal from the cut surface of the stem The divisions of the cortex cells induced only were restricted to the inner layers near by the pericyele. The present observation suggests that the interpretation for the variations of the callus forms may be elaborated further when the roles of callus of the different sources will have been explored. There were three stages in the course of callus development from the cut sur- face of stem-segments, namely, activation, division and formation. These three dovelopmental stages were characterized by changes in cell morphology of the population as well as in the cell division, grawth and the relative RNA accomulation in the callus tissue. The results are shown in table 1. The formation stage proposed in this paper differs with the differentiation phase (Yeoman, 1970, 1973) on the differen- tiation of the tissues and it is suggested that appearance of wound-cambinm and differentiation of the parenchyma in this stage may be considered as the characteristics of callus development. The general conceptions of activation, dedifferentiation and differentiation are also briefly discussed.
Wang Kai-ji, Zhang Pi-fang, Ni De-xiang, Zhu Xiu-zhu, Yang Wei-qin and Bao Zi-hua. Cytohistological Studies on the Tissue Culture of Olea europaea L. I. Development of Callus in Vitro[J]. J Integr Plant Biol., 1979, 21(2): -.
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