【作者】 蒋培东；

【导师】 李展；

【作者基本信息】 安徽农业大学 ， 作物遗传育种， 2004， 硕士

【摘要】 玉米的对生性状是一个新的变异类型，其叶片和果穗均为对生，是高产育种极其珍贵的种质资源。本试验利用对生性状转育获得的六组对生和互生姊妹系，首次研究了对生玉米与互生玉米的染色体核型差异；对其过氧化物酶同工酶、过氧化氢酶同工酶、多酚氧化酶同工酶和超氧化物歧化酶同工酶进行了测定和比较；还对玉米对生性状的遗传选择和组配效果进行了研究，结果表明：1.采用风油精法制片，对对生玉米和互生玉米染色体进行核型分析。首次发现对生玉米的染色体含有2对随体，而互生玉米却只有1对。除了第6对染色体短臂上有随体外，另外1对随体主要分布在第10对染色体短臂上，且随体大小、形态与第6对染色体有所不同。对生玉米和互生玉米在核型上的差异，为对生玉米的细胞遗传学研究提供参考依据。但这一差异是染色体结构变异还是基因表达形式，有待进一步探讨。2.通过对生玉米和互生玉米花粉母细胞减数分裂前期Ⅰ的观察，发现对生玉米在减数分裂偶线期和粗线期出现双核仁，在终变期有两对染色体连在核仁上，而在互生玉米中未曾发现。这一现象与对生玉米染色体含有两对随体有一定的内在联系。3.在染色体制片过程中，用5种预处理药剂对试验材料进行预处理，其中以1.25μl /ml风油精溶液（以饱和对二氯苯为溶剂）的效果最好。本试验还对去壁低渗火焰干燥法制片和风油精法制片进行了比较。就玉米染色体而言，风油精法制片效果比去壁低渗火焰干燥法制片要好。这种染色体制片技术可以为其他植物染色体制片提供一定的借鉴。4.通过6组对生玉米和互生玉米姊妹系的过氧化物酶(POD)、过氧化氢酶(CAT)、多酚氧化酶(PPO)、超氧化物歧化酶(SOD)同工酶分析，发现4种同工酶的酶带多态性水平都较高。在4种同工酶中，对生玉米和互生玉米姊妹系都存在一条共有带，且属于强宽带；同时对生玉米自交系都存在特征带。试验材料中对生玉米为对应互生玉米的近等基因系，所以认为在同工酶谱中，对生玉米显现的特征性酶带可能是对生性状基因表达的结果。5.通过连续定向选择，大多数对生玉米自交系后代的对生频率，均随选择世代的增加而增加，以至于达到遗传稳定。所以连续定向选择对获得稳定对生系是一种有效的技术途径。对生性状在不同的遗传背景下，其定向选择的进程和效率是不同<WP=4>的。6.利用对生×对生、对生×互生或互生×对生、互生×互生三种组配方式，可以进行全对生F1杂交种的选育。不同的组配方式，其选育效果是不同的。从F1对生率来看，对生×对生＞对生×互生（互生×对生）＞互生×互生；从F1优势来看，互生×互生＞对生×互生（互生×对生）＞对生×对生。因此，可以利用含有不同对生基因的互生自交系来组配杂交组合，以期获得全对生F1杂交种。本文的创新之处在于首次系统的进行了对生玉米的核型和同工酶分析，并对玉米对生性状的遗传选择和组配效果加以分析研究，为对生和含有不同对生基因自交系的选择、对生杂交组合的亲本选配以及对生玉米有效地应用于玉米高产育种提供了重要的理论依据。更多还原

【Abstract】 Oppositifolious character of maize is a new variation type, whose leaf and kernel are both oppositifolious, which is a high-yield breeding germplasm resource. The experiment has been carried out with sis-group oppositifolious and alternate sister-lines through oppositifolious character transfering, initially analysed their differences in chromosomal karyotype, and biochemically studied their peroxidase, catalase, polyphenoloxidase and superoxide dismutase isozymes. The paper has also studied the genetical selection and combination effect of oppositifolious character. The results are as follows:1.Chromosomal karyotype analysis of the oppositifolious and alternate maizes has been carried out with the method of essential balm. It has been found initially that the oppositifolious maize has two pairs of satellites, while the alternate maize only has one pair of satellites. Besides a pair of satellites in the short arms of 6th chromosomes, another pair of satellites are mainly in the short arms of 10th chromosome. At the same time, the size and morphology of the second pair of satellites are different with satellites in the 6th chromosomes. Differences in chromosomal karyotype of the oppositifolious and alternate maizes can provide good references to the oppositifolious maizes in cytogenetic study. However, whether the differences are caused by chromosomal structural variation or gene expression form, it will need a further query. 2.Through observing meiosis prophaseⅠof pollen mother cell of oppositifolious and alternate maizes, it has been found that in oppositifolious maizes bi-nucleolus is existing in zygonema and pachynema and two pairs of chromosomes are connected with the nucleolus in diakinesis, which is not found in alternate maizes. This phenomenon probably has an inner link with oppositifolious maizes having two pairs of satellites.3.Five preparatory treatments in the chromosomal technique of maize are carried out. The result shows that 1.25μl/ml essential balm solution has the best effect. In the experiment, the comparison of the modified F-BSG method and essential balm method has been done. As far as the maize chromosomes are concerned, the effect of the essential balm method is better than that of the modified F-BSG method. This chromosomal technique may provide a consult for other plant chromosomal preparation.4.Through analyzing the spectrum of four isozymes (peroxidase, catalase, polyphenoloxidase, superoxide dismutase) of the oppositifolious and alternate sister-lines, <WP=6>it can be found that the polymorphism level of four isozymic bands is higher. The oppositifolious and alternate sister-lines all have the same band which belongs to strong and wide band in four isozymes. From the four isozymic bands, some specific bands can be seen in the oppositifolious self-lines. Because the oppositifolious and alternate maizes in this experiment are near isogenic lines(NILS), the specific bands of oppositifolious maizes in the isozyme maybe arise from the expression of oppositifolious character genes. 5.By continuously orientational selection, the oppositifolious frequencies of the most oppositifolious offsprings are increasing as selective generations are growing, till they are genetically stable. So continuously orientational selection is an effective technical way for obtaining stable oppositifolious lines. When the oppositifolious character is in different genetic background, the process and efficiency of the orientational selection is different.6.Full-oppositifolious F1 hybrid breeding can be carried out by three combination modes such as oppositifolious×oppositifolious，oppositifolious×alternate(alternate×oppositifolious), alternate×alternate. Different combination modes have different effects on the breeding of F1 full-oppositifolious combination.As far as oppositifolious frequency is concerned, oppositifolious×oppositifolious is the highest and oppositifolious×alternate(alternate×oppositifolious) is higher than alternate×alternate. In the view of F1 heterosis, alternate×alternate is更多还原