裸燕麦种子老化处理对其种质资源遗传完整性的影响

发布时间：2018-05-20 17:36

本文选题：裸燕麦 + 样本量　；参考：《内蒙古师范大学》2017年硕士论文

【摘要】：裸燕麦(Avena nuda L.)属禾本科(Gramineae)燕麦属(Avena L.),是一种重要的粮食兼饲草、饲料作物。裸燕麦种质以种子形式贮存。种子从形成到发育成熟,受到内外环境的影响,会不可避免地发生老化,其遗传完整性也会受到影响。本研究以裸燕麦2个品种定燕9号、燕科1号为材料,利用SSR分子标记技术分析评价裸燕麦种质在进行遗传完整性研究时所需的适宜样本量、种子老化和繁殖群体量因素对种质遗传完整性变化的影响,旨在为裸燕麦种质资源保存和更新标准的制定提供基础数据。主要结果如下:1.分别以10、20、30、40、50、60、70、80、90株为样本量梯度,研究裸燕麦定燕9号和燕科1号不同样本量群体的SSR等位基因数、有效等位基因数、香农指数等遗传参数的变化。结果显示:20对SSR引物进行扩增,分别检测到43、32个等位基因,平均每个位点检测到2.09、1.60个等位基因。样本量大小与等位基因数、多态位点百分率相关(定燕9号分别为0.002**和0.003**,燕科1号分别为0.015*和0.012*)。2种材料的样本量分别大于70和50时,等位基因数、多态位点百分率的S拟合曲线变化趋于平缓,其他参数的标准差减小。将基于SSR的遗传完整性分析中2种材料群体样本量确定为70株和50株。2.对2种裸燕麦材料经人工老化处理得不同发芽率群体,对其进行SSR遗传完整性分析。定燕9号中,发芽率群体低于D9-1(发芽率80%-85%)时,群体的等位基因数、有效等位基因数、多样性指数、香农指数均与对照群体D9-0(发芽率90%)存在显著差异,而群体D9-1(发芽率80%-85%)、D9-2(发芽率60%-70%)和D9-3(发芽率30%)间差异不显著,综合考虑群体之间遗传多样性参数及遗传一致度的聚类分析结果,提出当定燕9号种子发芽率降至85%以下时,需对其进行繁殖更新。燕科1号4个不同发芽率群体的各参数无显著差异,但均随发芽率降低呈逐渐降低的趋势。3.研究了燕科1号不同繁殖群体样本量对其遗传完整性的影响。样本量为50、100和150的3个繁殖群体的等位基因数、有效等位基因数、遗传多样性指数和香农指数与对照群体相比差异显著,3个繁殖群体之间差异均不显著。等位基因数、多态性位点数、多态位点百分率低于对照群体,故繁殖群体样本量对其种质遗传完整性的影响不显著。4.将样本量为50、90的群体与繁殖群体量为50、100的群体进行等位基因数、有效等位基因数、遗传多样性指数、香农指数进行相关性分析,均呈极显著正相关(分别为0.003**、0.002**),且样本量(90)与繁殖群体量(100)的Pearson相关系数大于样本量(50)与繁殖群体量(50)的Pearson相关系数,达0.998。说明在生产实际中样本量(90)、繁殖群体量(100),更能代表该群体的遗传完整性。
[Abstract]:Avena nuda L. Avena L., an important forage and forage crop. Naked oat germplasm is stored in seed form. Seed aging and genetic integrity will inevitably occur due to the influence of internal and external environment on seeds from formation to maturity. In this study, two varieties of naked oat, Dingyan 9 and Yanke 1, were used to analyze and evaluate the suitable sample size of naked oat germplasm for genetic integrity study by using SSR molecular marker technique. The effects of seed aging and breeding population quantity on genetic integrity of germplasm were studied in order to provide basic data for the establishment of conservation and renewal criteria for naked oat germplasm resources. The main results are as follows: 1. The variation of SSR alleles, effective alleles and Shannon index in different populations of Dingyan 9 and Yanke 1 of naked oat were studied with the sample size gradient of 10H20, 30Pu, 40FU, 60Pu, 70CU, 800, respectively, and the variation of genetic parameters such as the number of SSR alleles, the number of effective alleles, and the Shannon index were studied. The results showed that 43 alleles and 32 alleles were detected by the amplification of 20 pairs of SSR primers, with an average of 2.09% 1.60 alleles per locus. The sample size was correlated with the number of alleles and the percentage of polymorphic loci (Dingyan 9 was 0.002 ~ * and 0.003), Yanke 1 was 0.015 * and 0.012 ~ (2) respectively, and the number of alleles was more than 70 and 50, respectively. The S-fitting curve of percentage of polymorphic loci tended to change slowly and the standard deviation of other parameters decreased. The population samples of two materials in genetic integrity analysis based on SSR were determined to be 70 plants and 50 strains. 2. The population with different germination rates was obtained by artificial aging of two kinds of naked oats, and the genetic integrity of two varieties of naked oats was analyzed by SSR. In Dingyan 9, the number of alleles, effective alleles, diversity index and Shannon index of the population were significantly different from those of the control population D9-0 when the germination rate of the population was lower than that of the control population D9-1 (germination rate 80 -85), and there were significant differences in the number of alleles, the number of effective alleles, the diversity index and the Shannon index between the two populations. However, there was no significant difference between population D9-1 (germination rate 80 -85) and D9-3 (germination rate 30%). Considering the results of cluster analysis of genetic diversity parameters and genetic consistency among populations, it was proposed that when the germination rate of DJ9 seed decreased to less than 85%, It needs to be propagated and renewed. The parameters of four different germination rate populations of Yanke No. 1 showed no significant difference, but all showed a decreasing trend with the decrease of germination rate. The effect of sample size of different breeding populations of Yanke 1 on its genetic integrity was studied. The number of alleles, effective alleles, genetic diversity index and Shannon index of three breeding populations with 50100 and 150 samples were significantly different from those of the control population, but there was no significant difference among the three breeding populations. The number of alleles, the number of polymorphic loci and the percentage of polymorphic loci were lower than those of the control population, so the effect of sample size of breeding population on the genetic integrity of the germplasm was not significant. The number of alleles, effective alleles, genetic diversity index and Shannon index of population with sample size of 50 ~ 90 and reproduction population of 50100 were analyzed. The correlation coefficient of Pearson between the sample size (0. 003) and the breeding population (100) was higher than that of the sample size (50) and the Pearson correlation coefficient (0. 998). The results showed that the sample size was 90% and the reproductive population was 100%, which could represent the genetic integrity of the population.
【学位授予单位】：内蒙古师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S512.6

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