Studies On The Heredity And Variation Of Embryogenic Callus Of Maize Transgenic Reciptients

Callus were induced from immature embryos of inbred line of maize 5010, 502, S2 , S4 , and Nongda ,effects of different factors on the rate of inducement of embryogenic callus (EC.) were analyzed by inducing , culturing, differentiating and plant regenerating, the variation of EC. was studied by cytology biochemical traits of young plants and mature plants in fields . some variations were recorded by photos .The effect and mechanism of 2,4-D was fully analyzed . it shows that the 2,4-D is necessary for inducement and culturing ,but it is also the main factor which results in variation.using 2.0mg/L in inducement ,1.0mg/L in culturing and later reducing the concentration of 2,4-D gradually is benefit for genetic stability ,high frequency culturing can promote the growth of callus and reduce the differentiation in culturing. at the same time ,it is one of the factors which leads to the unstable of genetic .with the frequency of culturing increasing ,the rate of differentiating reduces ,and the variation of plants increases,20 days frequency is adaptive .Rules of EC.'s genetic stability are firstly discussed ,and the way of establishing efficient transgenic recipients is found .using the materials in the experiment .it is stable in 3-5th generations ,they can be used as transgenic recipients ,the 6~10th ones also can be used but is inferior ,and it can't be used in 11~20th generations because of its high frequency variation.