【作者】 刘桂珍；

【导师】 吕德彬； 许自成；

【作者基本信息】 河南农业大学 ， 作物遗传育种， 2004， 硕士

【摘要】 烟草叶片中含氮化合物的种类可大体分为蛋白质、游离氨基酸、生物碱、硝酸盐以及烟草特有亚硝胺（TSNA）等，其中硝酸盐、亚硝酸盐和生物碱是致癌物质烟草特有亚硝胺的前体物。了解这些前体物的遗传变异特性，对通过遗传改良途径降低烟叶中TSNA含量、提高烟叶品质与安全性具有重要的意义。本试验于2001年在信阳、郑州、商丘3个地点进行，按照Griffing双列杂交设计方法2，对6个烤烟亲本及其15个F₁代烤后烟叶的4种含氮组分进行了遗传变异、配合力效应及稳定性分析。主要结论如下： 1、多点试验的联合方差分析、描述统计分析和多重比较结果表明：烤后烟叶几种含氮组分（硝酸盐、亚硝酸盐、烟碱、总氮）在不同基因型间、地点间和部位间的差异均达到显著或极显著水平，表明烟叶含氮化合物的变异广泛存在。（1）对硝酸盐、亚硝酸盐含量而言，21个基因型（中部叶）的平均硝酸盐含量为2.83±0.68mg／g，变异系数为24.13％，平均亚硝酸盐含量为6.88±1.70μg／g，变异系数为24.63％。两者均以品种（系）8136、RG17、潘园黄的含量较高，红花大金元、中烟90、K326的含量较低；不同部位间差异呈现中部叶＞上部叶＞下部叶的趋势；地点间以商丘点含量最高，并和郑州、信阳两点的差异达到显著水平。（2）对烟碱、总氮含量来说，21个基因型（中部叶）的平均烟碱含量为2.26±0.37％，变异系数为16.43％；平均总氮含量为1.85±0.14％，变异系数为7.31％，两者在亲本间的变异系数均大于杂交种间的变异系数，表明亲本较杂交种对环境反应敏感。不同部位间差异呈现上部叶＞中部叶＞下部叶的趋势；总氮、烟碱在地点间、基因型间和部位间的变异与硝酸盐、亚硝酸盐的表现并不一致。 2、遗传率分析结果表明：4种含氮组分在3个地点均表现为加性烤烟几种含氮组分的遗传变异及配合力分析方差大于非加性方差，表明含氮成分的遗传主要由基因加性效应决定，但非加性效应对这几个性状的表达也起着重要的作用。就中部叶而言，硝酸盐的广义遗传率（心）在地点间的变幅为59.07一“.8%，狭义遗传率（嵘）为33.19礴8.90%;亚硝酸盐的嘴在地点间的变幅为6073一78.27%，麟为37.40一54.52%;烟碱的嘴在地点间的变幅为63.38-73.87%，麟为56.37⁶ 3.96%;总氮的嘴在地点间的变幅为 70.42-82.14%，嵘为41.60一69.23%。就不同部位而言，硝酸盐、亚硝酸盐的嘴均表现为上部叶>下部叶>中部叶，麟较低且规律不明显，表明存在较大的非加性变异;烟碱、总氮的麟均表现中部叶>下部叶>上部叶，但两者的嵘规律不一致。 3、简单相关分析结果表明:硝酸盐与亚硝酸盐、烟碱与总氮之间的相关均达到l%极显著水平，相关系数分别为0.5610和0.7962;硝酸盐、亚硝酸盐分别与烟碱、总氮之间的相关则未达到5%显著水平。4个含氮组分的中亲值分别与其Fl代的相关系数均达显著或极显著水平，说明在杂交种选育中，利用亲子相关关系对烟叶含氮组分进行遗传改良是有效的。 4、配合力方差分析结果表明:烟叶4种含氮组分的一般配合力 （GCA）和特殊配合力（SCA）方差均达到1%极显著水平，各组分GCA与SCA的均方比值在地点间的变幅为4.29一1 5 .51，说明这些性状的遗传以基因的加性效应占主导地位;与烟碱、总氮相比，硝酸盐、亚硝酸盐在各点的比值较小，说明这两个性状基因的非加性效应也占相当比重，这与含氮组分遗传率的分析结果相一致。 5、配合力效应分析结果表明:烤烟亲本含氮组分的一般配合力和组合的特殊配合力效应之间无必然的联系;对烟碱、总氮来说，应选用一般配合力效应适中、特殊配合力方差较大的亲本，而对硝酸盐、亚硝烤烟几种含氮组分的遗传变异及配合力分析酸盐而言，应选用一般配合力效应较低、特殊配合力方差较大的亲本。在本试验中，硝酸盐和亚硝酸盐选育的适宜亲本是中烟90、K326，烟碱选育的适宜亲本是8136，总氮改良的适宜亲本是红花大金元。不同组合各含氮组分的配合力总效应与其实际含量高度吻合，两者的相关系数接近为1。（亚）硝酸盐配合力总效应值较低的组合有K326x红大、K3 26x中烟90、潘园黄x红大等。 6、在育种实践中，烟叶硝酸盐和亚硝酸盐含量的反应量应是愈小愈好，广为应用的品种应是品种主效和互作均较小;烟碱、总氮含量的反应量以中等为宜，广为应用的品种应是品种主效中等而互作较小。品种的稳定性分析结果表明:酸盐含量及主效应值较低，在供试的6个亲本中，K326、中烟90的硝稳定性与适应性较好。采用A入卫吐1不同品种含氮组分的稳定性进行排序，结合较低的硝酸盐含量，模型对可知红花大金元、中烟90、K犯6在生产上利用价值较高。AN压叮模型与Ebethart和Russell模型的分析结果基本一致。更多还原

【Abstract】 Nitrogen compound contains protein, free amino acid , alkaloid, nitrate and tobacco-specific nitrosamines (TSNA) in tobacco leaves. The nitrate, nitrite and alkaloids are precursor to form tobacco-specific nitrosamines (TSNA). It is of great importance to know genetic variation of these precursor in decreasing the TSNA content and improving the quality and safety of tobacco leaves by genetic improvement. Experiments were located in Xinyang, Zhengzhou and Shangqiu cities in 2001. According to the method No. 2 of Griffing’s dialle mating design, a set of 6 parents with different genetic basis and their 15 F1 crosses were made. Genetic variation, combining ability effects and stability of the content of 4 nitrogen components in flue-cured tobacco leaves were analyzed. Main conclusions were as follows:1 The results of joint analysis of variance in multiple locations, descriptive statistics analysis and multiple comparison indicated that the variation of several nitrogen components containing nitrate, nitrite, nicotine, total nitrogen in flue-cured tobacco leaves are significant or highly significant among different genotypes, environments and leaf positions. So there existed widely variation for nitrogen components of flue-cured leaf.(1) As far as nitrate and nitrite be concerned, average content of nitrate of twenty-one genotypes was 2.83 ±0.68%, and coefficient of variation was 24.13%; average content of nitrite was 6.88 ± 1.70%, and coefficient of variation was 24.63%. Comparison among different parents showed that 8136, RG17 and Panyuanhuang hadthe high content and Hongda, Zhongyan90 and K326 had the low content; The trend was cutters > upper leaf >lugs among different leaf positions; Comparison among different locations showed that Shangqiu had the biggest content of nitrate and nitrite, and had significant difference with Xinyang and Zhengzhou at 1% level.(2) Considering content of nicotine and total nitrogen, average content of nicotine of twenty-one genotypes was 2.26 0.37%, and variation coefficient was 16.43%; average content of total nitrogen was 1.85 0.14%, and variation coefficient was 7.31%. The high variation coefficient among parents showed parents were more sensitive to environment than FI hybrids. The trend of content of nicotine of different positions was upper leaf >cutters >lugs. The variation of content of nicotine and total nitrogen was different from that of nitrate and nitrite among locations, genotypes and positions.2 The results of heritability in three locations indicated that the heredity of the content of four nitrogen components was controlled mostly by gene additive effects, and gene non-additive effect was also important. The range of hB2 of nitrate among locations was 59.07-66.8%, and h2N was 33.19-48.90%. The range of hB2 of nitrite among locations was 60.73-78.27%, and hN2 was 37.40-54.52%. The range of hB2 of nicotine among locations was 63.38 - 73.87%, and hN2 was 56.37-63.96%. The range of hB2 of total nitrogen among locations was 70.42 - 82.14%, and h2N was 41.60-69.23%. The hB2 of nitrate and nitrite of different positions showed the trend of upper leaf > lugs > cutters. The h2N was relatively low which indicated large non-additive effects. The hB2 of nicotine and total nitrogen among different positions showed lugs > cutters > upper leaf.3 Simple correlation analysis showed that the correlation coefficients of the content of both nitrate with nitrite and nicotine with total nitrogen were significant at 5% level. The correlation coefficients were 0.5610 and 0.7962, respectively. The correlation ofnitrite and nitrate with nicotine and total nitrogen weren’t significant, respectively. The correlation between mid-parent and F1 hybrid was significant at 5% or 1% level, which indicated that it is effective to improve nitrogen components according to the correlation of parent-offspring.4 The results of analysis of variance of combining ability of four nitrogen components indicated that the variation of GCA and SCA were signific更多还原