【作者】 雷雪峰；

【导师】 易津；

【作者基本信息】 内蒙古农业大学 ， 植物学， 2008， 博士

【摘要】 驼绒藜属植物为藜科半灌木旱生、超旱生植物,主要分布于北温带干旱、半干旱地区,目前该属植物全世界登记种有7个,中国有4个种和1个变种,其抗逆性强、营养丰富,具有良好的生态和经济价值。我国驼绒藜属植物花期较晚、结实率低、种子寿命较短、种群退化严重,为此我们从美国引进抗旱、抗寒、耐高温、生态幅宽、适应性强、开花结实早的北美驼绒藜进行引种驯化,为今后驼绒藜属植物品种选育及杂交育种奠定基础。本研究对在内蒙古引种的北美驼绒藜不同世代群体进行遗传变异规律的研究,包括生物学特性、形态学、细胞学、等位酶、分子遗传学等内容,主要结果如下:1.生物学特性研究结果表明北美驼绒藜4个世代群体间在物候期、开花动态、花粉活力、结实率、种子发芽率、活力指数及发芽指数等指标存在较大变异,而形态发育及叶片营养含量动态趋势变异较小;上述指标在世代间变异趋势为: BM0世代各指标测定值基本均小于其它三个世代,BM1世代次之,BM2和BM3世代最大且差异较小。2.研究表明北美驼绒藜表型性状存在显著或极显著差异。其变异规律为:枝条长度、再生小枝数、叶长、叶宽、株幅的变异系数随世代的增加而减小;株高、叶腋雌花数、枝直径随世代的增加而增大;其它性状在4个世代间变异无规律。广义遗传力分析结果表明:株高、叶腋雌花数、叶宽、雄花穗长遗传力较高,表明受遗传因素影响较大;叶长、枝直径、株幅遗传力较低,表明受环境因素影响较大;表型性状的遗传、表型相关性分析表明,部分表型性状变异受环境和遗传因子共同影响,如枝条长度与着生雌花节数、枝条长度与再生小枝数、着生雌花节数与再生小枝数等性状;少数表型性状间的相关性主要受环境因素影响较大,如叶长和叶宽;其它大部分性状间的相关性主要受遗传因素影响较大;遗传增益分析结果表明:在5%的选择压力下,雄花穗长、再生小枝数、株高、叶宽遗传增益相对较高,表明该性状具有较高的遗传获得量。3.细胞学研究表明,北美驼绒藜世代间核型未发生明显变异,其核型均属1A型,核型公式均为2n=2x=18=18m,染色体长度比和平均臂比变异系数较小,分别为7.66%和4.79%。4.等位酶水平分析表明,北美驼绒藜4个世代群体多态位点百分率均为85.71%;北美驼绒藜群体的遗传多样性较大,其中BM1世代群体的遗传多样性最大(He =0.4229),BM3世代群体的遗传多样性最小(He =0.3714);北美驼绒藜的遗传变异主要来自世代群体内(97.2%);北美驼绒藜4个世代群体遗传一致度分析表明世代相隔越远,群体间遗传一致度越小,相隔越近,遗传一致度越大。5.利用正交试验设计对北美驼绒藜ISSR-PCR反应的5因素(Taq酶、dNTP、引物、Mg2+和模板DNA)4水平进行试验,建立了适合北美驼绒藜的ISSR-PCR最佳反应体系,即20μl的反应体系中含有1×buffer,1.5U Taq酶,0.2mmol/L dNTP,0.5μmol/L引物,2.5 mmol/L Mg2+和10ng模板DNA。6.北美驼绒藜ISSR-PCR分析共检测到167个位点,多态百分率为89.22%,各世代基因杂合度为0.2725~0.2306,shannon多样性指数为0.4441~0.3888,表明北美驼绒藜种内存在较丰富的遗传多态性;世代间多态性的大小规律为BM0到BM1增大,之后逐代减小;4个世代群体的遗传变异有83.49%分布在群体内,有16.51%分布于群体间;随着世代的增加,群体间遗传分化逐渐减小,世代群体间相隔越远,其遗传分化系数越大;聚类结果显示,BM2和BM3世代首先聚为一支,然后与BM1世代聚为一大支,最后与BM0世代再相聚。更多还原

【Abstract】 Ceratoides belongs to Chenopodiaceae, which distributed extensively in Eurasia and mainly at arid and extra arid regions of the North Temperate Zone. This genera has 7 plant species all over the world, there are 4 plant species and 1 variation in China. This genera has great value of ecology and economy. Ceratoides in China owned the characteristics as later florescence, low setting percentage, shorter seed longevity and degeneration. On this account, we introduced Ceratoides lanata (Pursh) Powell of early florescence, high setting percentage. All these would provide academic base to breeding and crossbreed of new variety for the future. The paper chose different generations of C. lanata planting in China as the researching object, studied the regularity of genetic variation in biological characteristic, morphological, cytology, allozyme and DNA, revealed the characteristics and regularity of genetic variation after introduction, the main results were as follows:1. 4 generations of C. lanata were varying in phonological phases, floral dynamic, pollen viability, seed setting rate, germination rate, vigor index and germination index, while varied little in growth and nutrition. Variation trends of indexes above in different generations were: BM0 generation basically was the smallest, and then BM1, BM2 and BM3 generations were the biggest and which two were close.2. There was a larger variation of C. lanata phenotypic traits. Within generations, the variance coefficient of branch length, regenerated shoots, leaf length, leaf breadth, plant spread were all decreased while plant height, females flowers number in axil, branch diameter were all increased along with the increasing of generations. General potential analysis show that plant height, female flowers number in axil, leaf breadth, staminate flowers panicle length had higher genetic potential and were influenced mostly by genetic factor, while leaf length, branch diameter, plant spread had lower genetic potential and were influenced mostly by environmental factor; Correlation analysis about several phenotypic traits showed that between branch length and nodes number in female flowers, regenerated shoots, between nodes number in Female flowers and regenerated shoots were all influenced both by environmental and genetic factors, the relativity between leaf length and leaf breadth were influenced mostly by environmental factor, and relativities among other indexes were influenced mostly by genetic factor. Genetic gains analysis showed that under 5% choosing pressure, the genetic gains of staminate flowers panicle length, rege- nerated shoots, leaf breadth etc. were all higher. 3. The karyotype of 4 C. lanata generations were all belonged to 1A type which did not variance obviously, karyotype formula was 2n=2x=18=18m, and the coefficient of variation of chromosome length ratio and average arm ratio were 7.66% and 4.79%, respectively.4. The results of allozyme showed that percent of polymorphic loci of 4 generations of C. lanata all was 85.71%. Different generations of C. lanata all had a larger genetic diversity, and in which BM1 was the largest while BM3 was the least. Genetic variation of C. lanata derived from 4 generations populations. The farther of generations leaved the smaller of genetic identity, and the closer of generations leaved the larger of genetic identity.5. The orthogonal design was used to optimize ISSR amplification system of C. lanata in five factors (Taq DNA polymerase, dNTP, primer, Mg2+ and DNA templet) at four levels respectively. The best of reaction system of C. lanata was established, 20μl reaction system which contained 1×buffer, 1.5U Taq DNA polymerase, 0.2mmol/L dNTP, 0.5μmol/L primer, 2.5 mmol/L Mg2+ and 10ng template DNA.6. Results of ISSR-PCR genetic variance of C. lanata showed that 167 loci were detected in 16 ISSR primers, polymorphic loci percent was 89.22%,the gene heterogeneity of 4 generations was 0.2725~0.2306,shannon index was0.4441~0.3888,it showed that there was polymorphism in C. lanata. There was abundant diversity in C. lanata population, from BM0 to BM1, the diversity was increased and after BM1, it was gradually decreased. There was 83.49% genetic variance within generations and 16.51% among generations. Along with the increasing of generation, genetic differentiation among generations was decreasing; and the farther of generations leaved the larger of genetic differentiation coefficient. The results of clustering showed that BM2 and BM3 was the first cluster which with BM1 was the second cluster, and then with BM0 to be the third cluster.更多还原