The Establishment Of Plant Regeneration System On Maize And Studies On Transformation Of SsBHMT

Maize (Zea Mays L.) is a widely grown cereal crop and the most important fodder crop in the world today.It is significant in theory and application to establish an efficient and stable genetic transformation system of maize. Good receptor and plant regeneration system is an important prerequisite for transformation. Immature embryos from Zong 3, Zong 31, Lian 87, Qi 319, H04-36, Han 21, Mo 17 and Zong 31×Lian 87, Zong 3×Lian 87, Qi 319xLian 87, H04-36×Lian 87 were used for the study on the callus induction and regeneration. The resules show that callus culture of maize was significant affected by maize genotypes, also by medium and hormones.The Zong 31×Lian 87, Zong 31, Zong 3 and Qi 319 was suitable as the receptor for their higher performance both in induction of TYPEⅡembryonic callus and plant regeneration. Y6 was more suitable for Zong 31 x Lian 87, Zong 31,3 and Qi 319 as induction medium. Immature embryo regeneration system was established preliminarily. The mature embryos callus induction and plant regeneration conditions were also explored of lian 87, H04-36, Zong 3, Zong 31, Han 21 and Qi 319. The results show that the maize mature embryo callus induction was higher when subculture medium supplemented with 10 mg/L of AgNO3,100 mg/L of DTT, and 150 mg/L of L-cysteine; 6 regenerated plants were obtained from the inbred lines Zong 3, Zong 31 and H04-36. Mature embryo regeneration system was established initially. And compared the response of immature embryo and mature embryo in tissue culture, the results showed that the callus induction and plant regeneration was better than those of the mature embryo. The immature embryo callus induction of a maize genotype was higher and its mature embryo callus induction was higher too, there was correlation. Accodingly it can solve the inconvenience of immature embryo sampling time by screening maize genotypes preliminarily useing mature embryos as explants.Agrobacterium tumefaciens-mediated genetic transformation in germinating embryo of maize was very convenient and a practical method. It was relatively simple in operation and did not rely on tissue culture. Transgenic plants can be gotten rapidly. The method of cutting embryo was improved by peeling corn seed coat before cuting embryos. The strength and depth of cutting embryos was controled effectively to improve the transformation efficiency. Through optimizing the transformation conditions, the optimal inoculation time was 20 min, the optimal concentration of AS in co-culture medium was 200μmol/L, PPT concentration was 200 mg/L in the selecting solution. Four transgenic plants were obtained by PCR testing. The study established a system of genetic transformation of maize, which provides a basis for further researching the role of animal's SsBHMT gene on growth development and resistance of maize.