【作者】 李冬梅；

【导师】 李明；

【作者基本信息】 东北农业大学 ， 作物学， 2009， 博士

【摘要】 亚麻是最早被人类利用的作物之一,亚麻属共有200多个种,遗传资源丰富。栽培种亚麻包括油用和纤维用两种类型,纤维类型在纺织、材料、造纸等领域具有重要的经济价值,而油用类型的亚麻子中含有大量不饱和脂肪酸和木脂素（lignan）,对心脑血管疾病具有很好的疗效,具有巨大的商业开发价值。然而,尽管亚麻具有悠久的栽培历史,亚麻属植物的研究却处于初级阶段,对亚麻属植物资源还知之甚少,对亚麻栽培种的起源、演化和亚麻属植物的亲缘关系问题还存在很多分歧。本研究从形态标记、蛋白质标记、DNA标记三个角度探讨了部分亚麻属（Linum）植物（17个种）遗传多样性及栽培种亚麻（Linum usitatissimum L.）的演化,利用纤维素合酶编码区基因片段（CesA）及硬脂酰基载体蛋白脱氢酶基因（Sad2）,来探讨栽培亚麻的进化途径,同时,采用野亚麻群体（Linum stelleroides）为样本,来探讨野生亚麻居群的遗传丰富程度及基因流向,从而为研究栽培亚麻的进化途径和野生亚麻属资源的合理利用及保护提供理论依据和参考。本研究结果如下:1.亚麻的最佳SRAP-PCR反应体系为:总体系25μl,模板25ng、buffer1×、Mg²⁺ 2.5mmol/L、dNTPs 0.3mmol/L、引物0.2μmol/L、TaqDNA聚合酶2U/25μl体系。最佳反应程序为:94℃预变性3min,1个循环,94℃变性10s,35℃复性20s,72℃延伸1min,4个循环,94℃变性10s,54.5℃20s,72℃延伸1min,38个循环,最后72℃延伸7min,4℃保存。2.亚麻属植物具有丰富的遗传变异,17个种65份亚麻属材料的21个性状的种间平均变异系数为0.47,变幅为0.12-1.36,其中,变异系数>0.5的性状为:分枝习性>花冠颜色、花粉囊颜色>种皮颜色>叶主脉导管数>生长习性>叶形,观察性状的变异要大于测量性状,种内变异系数为0.02-0.25,种间变异大于种内变异。3.研究的65份材料的相似指数在0.577-0.993之间,野生种之间的相似系数变化范围为0.583-0.950,栽培品种间相似系数变化范围为0.841-0.993,其中,纤维用类型在0.897-0.993之间,而油用类型在0.841-0.987之间,野生种间具有更大的遗传差异,纤维用亚麻比油用类型具有更加狭窄的遗传基础。4.从形态、酶及基因水平证明,三种亚麻类型中,野生种与栽培种的油用类型具有更近的亲缘关系,而与纤维用类型关系最远,同时,在聚类上,油用类型不但有自己的小聚类群也与纤用类型聚在一起。5.对野亚麻Linum stelleroides群体及栽培亚麻（Linum usitatissimum L.）群体的分析发现,种群内部具有较小的遗传差异。种群间强烈分化,种群间具有较小的基因流动和较大的基因分化系数。6. Linum grandiflorum、Linum bienne、Linum angustifolium、Linum tenuifolium分别在不同的水平上距离栽培亚麻（Linum usitatissimum L.）亲缘关系最近,其中,在形态水平上Linum grandiflorum与栽培种最近,在酶水平上,Linum bienne、Linum angustifolium与栽培亚麻关系最近,在SRAP标记水平上,Linum angustifolium、Linum tenuifolium、Linum bienne与栽培亚麻关系最近。7.本研究支持栽培亚麻的多起源观点,不支持Robin G.等人提出的栽培亚麻单一起源于Linum bienne的观点,且初步认为Linum bienne种对栽培亚麻的演化有一定贡献。更多还原

【Abstract】 Genus Linum L. was one of crops used by human firstly, and it comprises more than 200 species, there are abundant genetic resources. The cultivated species comprises two types, one is fibre flax, the other is linseed(oil flax). Fibre flax had important economic value in textile industry, materials, paper industry,and so on, so was the linseed in business for its abundant insaturated fatty acid and lignan content, which resist against cardiovascular and cerebrovascular diseases. Although has a long cultivated history, the research to Genus Linum L. was at initial phase. The little understanding was knewn to Genus Linum L., and there are many different views to origin, evolution of cultivated flax and relationship within Genus Linum L.Genetic diversity within part of Genus Linum L.and the evolution of cultivated flax(Linum usitatissimum L.) were analysised from phenotypes, peroxidase polymorphism and DNA polymorphism of SRAP markers in the study. Evolutionary pathway of the cultivated flax was disscussed by analysising homologous sequence of gene CesA CDS section and gene Sad2. Otherwise, local wild flax(Linum stelleroides) was taken as sample to understand the genetic diversity and gene flow(Nm) of population, and it could supply theoretical basis for evolutionary pathway of cultivated flax and wild flax utilization reasonable. The results was as follows from the study:1. the optimal SRAP-PCR reaction system in flax were made certain as follows: 1×buffer, 2.5mmol/L Mg2+, 0.3mmol/L each dNTP, 0.2μmol/L primer, 0.08U/μl Taq DNA polymerase, and 1.2ng/μl flax DNA template in a final volume of 25μl, and the optimal amplification protocol was: 94℃3min, (94℃10s,35℃20s,72℃1min)×4,(94℃10s,54.5℃20s,72℃1min)×38, 72℃7min,held at 4℃.2. Genus Linum L.had abundant genetic variation, the average mean of variation coefficient based on 21 phenotype characters from 65 accesions within 17 species was at 0.47, the range was at 0.12-1.36, in which, variation coefficient value of several characters >0.5, the order was: branching habit>corolla color, anther color> seed color>the number of vascular cells in main nervation>growing habit>shape of leaf. The variation of observed characters was higher than that of measured characters. The range of variation coefficient in species was at 0.02-0.25, and the variation among species was higher than that of in the species.3. Similarity index range among 65 accessions was at 0.577-0.993, and among wild species was at 0.583-0.950, and among cultivated varieties was at 0.841-0.993, in which, that of fibre flax was at 0.897-0.993, the linseed was at 0.841-0.987. From above, the highest variation was among wild species, fibre flax had narrower genetic basis than linseed. 4. Wild flax had closer relationship with linseed than fibre flax from the evidence of phenotypecharacters, isozyme polymorphism and DNA polymorphism amplified by SRAP marker. Linseed not only had its own clustering group, but also existed in fibre flax clustering group.5. It was found that differentiation was strong between the local wild flax species population(Linum stelleroides) and cultivated species population(Linum usitatissimum L), there was little gene flow and big gene dirrerentiation coefficient between two species population.6. Linum grandiflorum、Linum bienne、Linum angustifolium、Linum tenuifolium were close to cultivated flax in similarity, in which, Linum grandiflorum was close to cultivated flax at phenotype, Linum bienne、Linum angustifolium was at isozyme, and Linum angustifolium、Linum tenuifolium、Linum bienne was at DNA polymorphism amplified by SRAP marker.7. It supported the view that cultivated flax had many origins, and didin’t support the only origin from Linum bienne, and Linum bienne was considered that contributed to envolvement of cultivated flax更多还原