【作者】 胡超越；

【导师】 王振民；

【作者基本信息】 吉林农业大学 ， 作物遗传育种， 2003， 硕士

【摘要】 大豆油脂脂肪酸主要由饱和脂肪酸（棕榈酸、硬脂酸）和不饱和脂肪酸（油酸、亚油酸和亚麻酸）组成。大豆油脂中以亚油酸含量最高，硬脂酸最低。油酸、亚油酸对人体有益，它对防止高血压和心脏病等有重要作用。大豆油脂中的亚油酸含量高，豆油的营养价值就高。亚麻酸易使油脂氧化变劣，使豆油营养价值降低。棕榈酸和硬脂酸，不易消化吸收，人类过多食用，会造成肥胖和心血管疾病。大豆油脂脂肪酸改良的策略，应是在提高亚油酸含量的同时，适当降低亚麻酸含量。本研究试图对大豆油脂脂肪酸含量的遗传变异规律及配合力进行分析，以其为大豆油份品质育种的亲本选配和性状选择提供参考依据。 供试材料共5份，包括2份吉林省主推的大豆品种：吉农7号（P₁）、九农21号（P₂），3份引自美国的低亚麻酸材料Century（P₃）、A₅（P₄）、C₁₆₄₀（P₅）。2000年按Griffing完全双列杂交方法2配制10个杂交组合，2001年用C₁₆₄₀（P₅）和（P₁×P₅）、（P₂×P₅）、（P₃×P₅）、（P₄×P₅）各杂交组合的F₁代进行回交，2002年将5个亲本、10个杂交组合F₁、4个回交组合BF₁和10个自交组合F₂，按随机区组设计种于吉林农业大学育种试验田。分析研究了大豆油脂脂肪酸含量与主要农艺性状、品质性状（蛋白质、脂肪）及油脂脂肪酸组分间的遗传相关，并对油脂脂肪酸和单株粒重、脂肪含量、百粒重、亚麻酸含量进行了通径分析，同时估算了油脂脂肪酸含量的杂种优势、配合力、遗传力及回交的改良潜力。结果表明： 1、大豆杂种后代油脂脂肪酸含量介于双亲之间，棕榈酸、油酸、亚油酸含量略低于双亲平均值，从个别组合看，F₁代具有杂种优势，但从组合平均看，只有硬脂酸和亚麻酸具有杂种优势，超亲优势的表现和杂种优势的表现基本相同。 2、棕榈酸、硬脂酸、油酸、亚麻酸含量和百粒重的遗传相关均为正值，亚麻酸含量与百粒重呈极显著的正相关，而亚油酸含量与百粒重的遗传相关为负值，通过百粒重可以对亚麻酸、亚油酸以及棕榈酸进行间接选择。 3、油酸与亚油酸、亚麻酸的遗传相关较稳定，所有研究均呈显著负相关，利用这种相关关系，采用间接选择法，可以选出油酸含量高的材料，既提高了油酸含量，又降低了亚麻酸含量。吉林农业大学硕士学位论文大豆油脂脂肪酸含量的遗传变异及配合力分析 4、本研究中亚油酸含量和亚麻酸含量呈极显著的负相关，通径分析的试验结果和相关分析的结果相一致，这个结果只和徐豹、平春枝的研究结果相同，和多数人的研究结果相反，.这一研究使得在选育亚麻酸含量低的材料的同时又保持材料的高亚油酸含量成为可能。 5、油酸、亚麻酸含量对单株粒重的直接效应为0.8467、0.5079，油酸、亚麻酸含量对单株粒重的遗传相关系数为0.4374、0.1983，油酸、亚麻酸含量对单株粒重的遗传相关分析结果和通径分析结果基本吻合。 6、油酸、亚油酸含量对百粒重的直接效应为一1 .78、一1.8855，亚油酸含量对百粒重的遗传相关为极显著负相关，亚油酸含量对百粒重的相关分析结果和通径分析结果相一致。油酸含量对百粒重的遗传相关为正值，油酸对百粒重的负向效应主要被亚油酸含量对百粒重的间接正效应（1 .0917）所掩盖。 7、油脂脂肪酸含量对脂肪含量的直接效应依次为亚油酸>亚麻酸>油酸>棕桐酸>硬脂酸，亚油酸、亚麻酸对脂肪含量的直接效应较大。4种脂肪酸含量对亚麻酸含量的直接效应依次为亚油酸>油酸>棕桐酸>硬脂酸，提高含油量和改善油脂品质并不矛盾。 8、油脂脂肪酸含量除硬脂酸外，均属数量遗传，且以加性效应为主。亲本油脂脂肪酸含量的平均值与一般配合力效应值密切正相关。本试材中，美国品种C1640的油酸、亚油酸、亚麻酸的含量平均值和一般配合力效应值均较大，是提高油酸、亚油酸含量、降低亚麻酸含量的较好亲本。亲本吉农7号油酸含量平均值和一般配合力效应值最大，当以提高油酸含量为育种目标时，吉农7号是较好亲本。亲本Century棕桐酸含量平均值和一般配合力效应值最大，足降低棕桐酸含量的较好亲本。 9、而亲本的一般配合力效应值与特殊配合力效应值表现不一致，不能通过亲本的一般配合力效应值的表现来判断特定组合特殊配合力的表现。通过特殊配合力效应值的比较，组合P3 x P4是高油酸、高亚油酸、低亚麻酸的最优组合。在回交组合中，（PI/PS）x PS、（P:x PS）/PS比较好，在亚麻酸含量得到有效降低的同时，油酸同时得到提高，亚油酸稍有提高或降低不明显。吉林农业大学硕士学位论文大豆油脂脂肪酸含量的遗传变异及配合力分析 10、本研究分别用方差分析法和配合力方差分析法估算了油脂脂肪酸的广义遗传力，方差分析法估算的广义遗传力值偏高。亚油酸、亚麻酸的广义遗传力、狭义遗传力均较高，可在早世代进行直接选择;棕桐酸、油酸的广义遗传力、狭义遗传力均较低，硬脂酸的狭义遗传力为0，不宜在早代进行直接选择，可利用与其它性状的遗传相关进行间接选择。 11、当以降低亚麻酸含量为育种目标时，用低亚麻酸材料进行回交对降低亚麻酸含量有改良潜力?更多还原

【Abstract】 The oil fatty acids of soybean mainly consist of saturated fatty acids (palmitic and stearic) and unsaturated fatty acids (oleic, linoleic and linolenic). The character of oil of soybean is relation to the composition and proportion of unsaturated fatty acids in soybean oil. Oleic and linoleic are good for health and are important for avoiding hypertension and heart disease etc. The higher linoleic content is, the higher value of nutrition of oil is. Linolenic is easily to cause the value of nutrition of oil to decline. Because palmitic and stearic are hard to be digested and absorbed, they are harmful to people’s health. The strategic of improving oil fatty acids in soybean is to increase linoleic content with decrease linolenic content. The aim of the experiment is to analyze the genetic variation and combing ability of oil fatty acid contents, and the conclusion of the experiment could be as a reference for characters selection of quality breeding of soybean.The two popularized cultivars in Jilin are Jinong No.7 (P1) and Jiunong No.21 (Pa), and three American low-linolenic materials are Century (P3), A5 (P4) and C1640 (P5). The five parents were used as parents to make complete diallel crossing in accordance with the Griffing’s method 2. The crosses of P1 x P5, P2 x P5, P3 x P5 and P4 x P5 were backcrossed by C1640- The genetic correlations between oil fatty acids and main agronomic characters, quality traits and components of oil fatty acids were analyzed. At the same time, the path-coefficients of oil fatty acids to SWP (the seeds weight per plant), oil content, 100SW(100 seeds weight) and linolenic content were processed. The heterosis, combining ability and heritability of oil fatty acids were also estimated. The results showed that:(1) The average of oil fatty acid content of hybrid is between averages of two parents. The contents of palmitic, oleic and linoleic are slightly lower than the averages of their parents. Heterosis of mid-parent is in the specific crosses. Stearic and linolenic indicated heterosis of mid-parent in the view of mean of crosses. The result of over-parent heterosis analysis is the same as heterosis of mid-parent.(2) The genetic correlation between 100SW and the contents of palmitic, stearic, oleic and linolenic is positive. The genetic correlation is highly positive between the content of linolenic and 100SW. The genetic correlation is negative between linoleic content and 100SW. The contents of linoleic, linolenic and palmitic can be selectedindirectly by 100SW.(3) Oleic is very stability and highly negative genetic correlation with linoleic and linolenic., We can select indirectly the material with high content of oleic, namely, increasing oleic content and decreasing linolenic content simultaneously by this genetic correlation.(4) The highly negative correlation between linoleic and linolenic accorded with the result of path-coefficient analysis. It is the same as the results of Xu Bao’s and Ping Chunzhi’ s researches, and it’s contrary to the results of many other researches. It’s possible for selecting low content of linolenic and maintaining high content of linoleic simultaneously with the negative correlation.(5) The direct path-coefficients of contents of oleic and the linolenic to SWP were 0.8467 and 0.5079 respectively. The genetic correlation coefficients of contents of oleic and linolenic to SWP were 0.4374 and 0.1983 respectively. The result of path-coefficient analysis almost accorded with that of genetic correlation analysis.(6) The direct path-coefficients of oleic and linoleic to 100SW were -1.78 and -1.8855 respectively. The genetic correlation of linoleic content and 100SW was greatly negative. The results of genetic correlation analysis coincide with the results of path-coefficient analysis. The genetic correlation between oleic content and 100SW was positive, and the direct negative effect of oleic content to 100SW was concealed by indirect positive effect through linoleic content to 100SW.(7) The direct effects of the oil fatty acid更多还原