玉米抗倒伏性遗传研究及杂种优势分析

发布时间：2018-10-08 13:46

【摘要】：本试验分为两部分内容:第一部分,以Non-Reid和Dom群骨干自交系为基础材料育成自交系,经鉴定选用5个具有代表性的改良系为被测系,以Reid、Non-Reid、Dom群中品质良好的骨干系为测验种,组配5×7共35个不完全双列杂交组合,加之郑单985、先玉335两个对照品种,进行杂种优势及配合力分析。第二部分,以试验设置6万/hm2、8万/hm2、10万/hm2三个密度为主处理,5个改良系及7个骨干系共12个自交系为副处理,采用裂区设计方法,通过与倒伏率的回归分析,研究影响玉米倒伏的主要因素及改良系在抗倒伏性状上的改良效果。主要研究结果如下:1.各主要性状的杂种优势分析结果表明,单株产量超标优势(郑单985和先玉335)的组合有14个,其中,超标优势值大于20%的强优势组合有2个,分别为JND2×PH6WC、JND5×8-F。改良系与Reid群、Non-Reid群、Dom群骨干自交系的杂交,各性状杂种优势值均表现较好的杂种优势模式为(Non-Reid/Dom)×Reid,具有较高的增产潜力。这种杂优模式是本地区今后的玉米主要优势模式。2.配合力分析结果表明,一般配合力分析综合性状表现较好的自交系为改良系JND2、JND3、JND5和骨干系PH6WC、郑58。特殊配合力分析表明,35个杂交组合中,特殊配合力综合性状表现较好的组合有6个,分别为JND2×郑58、JND2×A87、JND3×PH6WC、JND4×PMO、JND4×A87、JND5×郑58。在综合性状表现较好6个组合中,有3个组合的遗传基础为(Non-Reid/Dom)×Reid,进一步说明“两个类群间选系,第3群作测验种”这种模式具有可行性。3.不同密度下各节间茎秆压碎强度分析表明,各自交系茎秆压碎强度随节间上升、密度的增加均呈下降趋势,表现为第3节间至第5节间的下降幅度大于第2节间至第3节间的幅度。茎秆压碎强度改良效果较好的改良系为JND1、JND2和JND5,以JND5最好。倒伏率改良效果较好的改良系为JND2、JND5。4.茎秆主要性状与倒伏率的通径分析和偏相关分析显示,各节间压碎强度、节间长、穗位高系数、干重是决定倒伏率的首要因素。单位节间干物质量、长粗比、穗位、节间直径对倒伏率也有不同程度的影响。其中,压碎强度、干重、单位节间干物质量和节间直径对倒伏率呈负向效应,有一定的限制作用;节间长、穗位高系数、干重和穗位对倒伏率的效应为正效应。
[Abstract]:The experiment was divided into two parts: in the first part, the inbred lines were bred from the backbone inbred lines of Non-Reid and Dom groups. Five representative improved lines were selected as tested lines, and the backbone lines with good quality in Reid,Non-Reid,Dom group were selected as test species. The heterosis and combining ability of 35 incomplete diallel crosses, plus Zhengdan 985 and Xianyu 335, were analyzed. In the second part, we set up three densities of 60,000 / hm ~ 2, 80,000 / hm ~ 2 and 100000 / hm ~ 2, and 12 inbred lines of 5 improved lines and 7 backbone lines were used as secondary treatments. The method of split zone design was adopted, and the regression analysis with lodging rate was adopted. The main factors affecting lodging in maize and the improvement effect of improved lines on lodging resistance were studied. The main results are as follows: 1. The results of heterosis analysis of main characters showed that there were 14 combinations with yield exceeding standard per plant (Zhengdan 985 and Xianyu335), among which, there were 2 strong heterosis combinations (JND2 脳 PH6WC,JND5 脳 8-F), where the value of excess heterosis was more than 20%. The heterosis pattern of heterosis between the improved line and the backbone inbred line of Reid Non-Reid group was (Non-Reid/Dom) 脳 Reid, with higher yield potential. This heterosis pattern is the main dominant pattern of maize in this area. The results of combining ability analysis showed that the inbred lines with better comprehensive traits in general combining ability analysis were improved line JND2,JND3,JND5 and backbone line PH6WC, Zheng58. The results of special combining ability analysis showed that there were 6 combinations with better comprehensive traits of special combining ability, which were JND2 脳 Zheng 58 (JND2 脳 A87) JND3 脳 PH6WC,JND4 脳 PMO,JND4 脳 A87 (JND5 脳 Zheng 58). The genetic basis of three combinations was (Non-Reid/Dom) 脳 Reid, which further showed that the model of "selecting lines between two groups and using group 3 as test species" was feasible. The analysis of crushing strength of internode culm at different densities showed that the crushing strength of stem increased with the increase of internode density, and the density increased with the increase of internode density. The decrease from the third Internode to the 5th Internode was greater than that from the second Internode to the third Internode. JND1,JND2 and JND5, were the best lines for improving the crushing strength of stem. JND5 was the best. The improved line with better effect of lodging rate improvement is JND2,JND5.4.. Path analysis and partial correlation analysis of the main characters of stem and lodging rate showed that the crushing strength, Internode length, ear height coefficient and dry weight were the primary factors to determine the lodging rate. Dry weight of unit Internode, ratio of length to diameter, ear position and Internode diameter also had different effects on lodging rate. Among them, crushing strength, dry weight, dry weight per unit Internode and internode diameter have negative effect on lodging rate, and the effects of Internode length, ear height coefficient, dry weight and ear position on lodging rate are positive effects.
【学位授予单位】：吉林农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S513

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