转AhCMO基因玉米后代的获得及耐盐性鉴定

Recovery and Salt-tolerance Evaluation of Maize Transgenic Progeny with AhCMO Gene

试验采用超声波辅助花粉介导法将山菠菜胆碱单加氧酶似hCMO）基因转入玉米自交系‘郑58’中，经抗生素筛选、PCR检测及白花授粉获得转CMO基因的T2代玉米种子。选取5份T2代玉米种子盆栽进行耐盐性鉴定试验。首先针对其非转基因受体材料筛选出耐盐性鉴定浓度，其后通过生理生化指标对转基因T3代株系进行耐盐性鉴定，同时筛选耐盐性强的株系。结果表明：耐盐性筛选及鉴定的适宜浓度为250mmol／L；依据对苗期生理生化指标的测定分析，在250mmol／LNaCl胁迫下，转基因玉米植株的超氧化物歧化酶（SOD）活性、过氧化物酶（POD）活性及叶绿素含量高于非转基因玉米，丙二醛（MDA）含量低于非转基因玉米。SOD活性提高了2％-208％；POD活性提高了22％～65％；叶绿素含量增加了8％～61％；MDA含量减少了3％～93％。试验表明，耐盐基因CMO的转化提高了玉米的耐盐性。依据生理生化指标变化情况建立的耐盐性级别评价方法显示，5份参试株系中耐盐性比对照提高3级的有2份。

In this study, A hCMO gene was introduced into maize inbred “Zheng58” by pollen-mediated transfor- mation approach assisted with ultrasonication. T2 transgenic seeds were obtained through antibiotic screening, PCR detection and self-pollination of T1 generation plants. Five T2 generation seeds were grown in pots to evaluate their salt tolerance. The results indicated that 250 mmol/L NaC1 was the appropriate concentration for evaluating salt tolerant transgenic lines. Analysis on physiological and biochemistry indices indicated that the activities of superoxide dismutase （SOD）, peroxidase （POD） and chlorophyll content of transgenic lines be higher than non- transgenic control plants, their malonaldehyde （MDA） content be lower than non-transgenic ones under the stress of 250 mmol/L NaC1. In transgenic lines, SOD activity was increased by from 2% to 208%; POD activity was increased by from 22% to 65%; chlorophyll content was increased by from 8% to 61% and MDA content was decreased by from 3% to 93%. In conclusion, the introduction of CMO gene improved salt tolerance of the maize plants; Based on evaluation result, two of the five transgenic lines had salt-tolerance levels scored three grades higher than the control.