Difference Analysis Of Growth And Photosynthetic Characteristics In Six Maize Lines And Hybrids Via A Diallel Design

Maize is the world's most widely grown crops, planting area in China only smaller than the United States. The basis of characteristics of photosynthesis of maize, maize breeding on the development of guidance is necessary.Two tropical, the Ki50 and Y46-1-1, and MON2,87-1, Y1218, and Xin9101-1/o2 and so on temperate maize parent diallel cross and their hybrids, for a total of 36 species of material were cultured with soil in pot. Analyze and compare their photosynthetic characteristics and growth in the seedling stage on physiological characteristics and genetic differences on combining ability. The main results were summarized as follows:1. Dffierent growth rates of maize seedings were significant. The parents Xin9101-1/o2 and Y1218 in the 40 dsys seeding have heightest plant height and biomass, and the'height and biomass of the offspring were always highter than their parents and heterosis significantly.20day seeding materials in a variety of photosynthetic parameters are significantly different between the net photosynthetic rate of offspring and parents, which was no difference between the regularity of the genetic changes. Photosynthetic characteristics of different maize varieties were significantly different. In this experiment,36 maize varieties on the net photosynthetic parameters for cluster analysis of 36 maize cultivars were divided into three categories. The first category concludes 12×2,12×4,12×5,12×8,2×8,5×12,5×8,8×9 with best photosynthetic performance,for best-class cultivar;The second class concludes 2,4,5,8,12,2×12,2×4,2×5,2×9,4×2,4×5,5×2,5×4,5×9,8×12,8×2,8×4, 9×12,9×2,9×4,9×5 and 9×8 with better photosynthetic performance, for good-class cultivar; The third class concludes 9,12×9,4×12,4×8,4×9,8×5. The crown is poor grade.2. In this experiment, for different combinations of genetic parents with the ability of the findings, different combinations of genetic parents with the ability of the GCA and SCA quite different, there are some genetic differences, the combining ability of each parent is not the same. Plant height, leaf area, shoot dry weight, root dry weight, net photosynthetic rate, stomatal conductance, transpiration rate, light compensation point, maximum net photosynthetic rate,ΦPSⅡ, Fv/Fm soluble protein content and RuBPCase activity GCA and SCA were significant levels of variance. The analysis of general combining abilities showed that5,8,12 were fegarded as ideal parents for increasing photosynthesis of hybrids varieties.3. In this experiment, the tested 36 varieties of maize photosynthetic parameters, chlorophyll fluorescence parameters, plant height, leaf area, dry matter yield, RuBPCase and PEPCase activity were studied. And photosynthetic characteristics of 36 varieties of comprehensive evaluation, the initial election of high light efficiency and good growing hybrid maize varieties are 2×5,2×8,2×12,5×2,5×8,5×12,8×5, 8×9,8×12,9×5,9×8,9×12,12×4,12×5 respectively.