Study On The Variant Character Of Maize Inbred Line Offsprings Received Exogenous DNA

With the methods of seed-immersion and pollen-tube-pathway, the exogenous DNA extracted from different plants was introduced into different maize inbred lines. The progenies appear various mutant types and the mutant characters are very abundant, mainly including the quality of field growth such as the height of plant, the height of fruit, the number of leaf, the color and morphology of leaf, the length and width of leaf, the area of leaf, the number of ear-ramify, the weight of 100 grain . the period of growth, etc.,variety of the zymogram of peroxidase isozyme (POD), the microscopic structure of leaf and the index of nutrition, and so on. Some of the varied characters were similar to donors, while others, resemble neither that of donors nor that of acceptor,were newly produced, which tended to be stabilized in D₃ generation. Some stable heredity and fine mutant material had been selected from 3 4 generation in 2003²005 year. The results are as follows: 1. The seed-immersion methodThe total DNA of donor from Heipi sugarcane was introduced into waxy corn 12-9-10 inbred lines with the density of 300μg/ml.The mutant rate of D₀ generation is 5.56%, the D₁ generation is 0.9%,and the opposite plants were obtained from D₀, D₂ generation. The results showed the structure of leaf was like donor's as well as recipient's, but most of the structure characters were from donors, and a peroxidase-isozymogram band which was of donor and not of receptor appeared respectively in Rf₁₁=0.50 and Rf₁₄=0.61 of peroxidase isozymogram, by the microscopic structure of leaf and the zymograms of peroxidase isozyme analysis. Continuously observing and counting on field-grow characters from D₀ to D₃generation, found that the plant height and fruit height shortened, the color of leaves was greener, compared with the acceptor. Analyzed its sugar, protein and starch content of the stable strain D3, the results indicated the sugar content increased ,the content of protein and starch increased or decreased. The good character strain D3-I has been selected, which increased in sugar and protein content and changed little starch content.2. The pollen-tube-pathway methodThe DNA extracted from donor waxy corn 12-9-10, with the density of 500ug/ml, was introduced Bangladesh super sweet maize inbred lines, 17h, 19h, 21h and 23h after pollination, the effect of variation is 17h>21h>19h>23h. Observed, counted and analyzed the quality of field growth of mutant plants in differently introduced time , the results showed some of the varied characters were similar to donor such as shortening the growth period or increasing 100-grain etc., some of characters were of neither the donor nor the acceptor such as the height of plant, the length and width of leaf, the number of ear-ramify etc., most of which tented to be stabilized in D3 generation, a little of which was slow. Analyzed the zymograms of peroxidase isozyme of the mutant plant after 17h pollination, the results also indicated that the zymograms of peroxidase isozyme of transferred progenies were different from the recipients(there was an increase of peroxidasic color and activity in Rf2=0.28, Rf4=0.34 and Rf5=0.39, and the mutant plant exhibited a specific band, named Rf8=0.60,that only belonged to the donor plant). The obvious difference in the parents and their progenies were corresponded with the phenotypes. Analyzing its sugar, protein and starch content of the stable strain D3 generation, found that the strains reserved not only the good characters of the receptors but also the new characters, such as increasing protein and starch content, changing little sugar content.3. The exogenous DNA was introduced into the maize inbred lines through seed-immersion and pollen-tube-pathway methods. The result showed that exogenous DNA had been introduced into the genome of receptor and expressed, and it created a new way to develop new maize material.