Transgenic Maize Plants Obtained By Pollen-mediated Transformation And Agronomic Trait Investigation Of Transgenic Maize Hybrids

Maize (Zea mays) is a crop belonging to gramineae. It plays a very important role in the national economy of China. New maize varieties with drought and saline tolerances, and disease-resistance bred by genetic engineering are important to increase maize yield. This study was composed of two parts. We obtained transgenic maize plant that Betaine aldehyde dehydrogenase (BADH) gene was transferred into maize inbreds by pollen-mediated transformation, and it is proved that pollen-mediated transformation is an effective transformation method. Transgenic maize hybrids were obtained by hybridization between transgenic maize inbreds which was obtained by pollen-mediated transformation, and then we compared the agronomic traits and disease-resistance of transgenic maize hybrids with that of non-transgenic counterpart. The result showed that the agronomic traits and disease resistance of transgenic maize hybrids is significantly superior. The research content and result were as follows:(1)In this study, maize transgenic system was established by pollen-mediated transformation. Based on the result of pre-experiment,20% sucrose solution was selected to be the osmo-regulator and the optimum ultrasonic treatment parameters was 6 times of treatment with power of 200W and the duration of 8s, and the interval of 5s. Betaine aldehyde dehydrogenase(BADH) gene was transferred into Maize inbred by pollen-mediated transformation and transgenic maize was obtained by PCR detection. One hundred and five of 393 transformed maize plants had set seeds and 464 seeds were obtained, the efficiency of seed-setting was 26.7%. 308 Km-resistant seedlings were survived after Km-resistant screening. Investigation by PCR showed that 98 of 308 Km-resistant maize plants were positive, and the efficiency of pollen-mediated transformation was 21.1%.(2)Thirteen transgenic maize hybrids were obtained by hybridization between transgenic maize line from'Hai 92-1'and 13 transgenic maize lines from'Jinhuang96C'.Agronomic traits of the 13 transgenic hybrids and their non-transgenic maize counterparts were investigated. The head smut incidences of the transgenic maize hybrids were significantly lower than that of their non-transgenic counterpart. The differences of plant height, ear position, ear length, ear grain weight and 100-kernel weight were significant between some transgenic maize hybrids and their non-transgenic counterparts, and the differences of ear diameter, ear weight and ear rows were not significant between them. Two superior cross combinations 2008060×Hai 92-1 (chi),2008060×Hai 92-1 (chi) were selected.(3)Poilen-mediated transformation was an effective transformation method in the study on maize transformation according to the result of these experiments. Two superior combinations were selected through investigating the agronomic traits of the transgenic hybrids and their non-transgenic counterparts. So it is showed that transgenic breeding technique plays a very important role in breeding new maize variety.