蒿柳居群、雌雄亚居群遗传多样性及雌雄株生理差异
发布时间：2018-01-11 02:12
本文关键词：蒿柳居群、雌雄亚居群遗传多样性及雌雄株生理差异 出处：《中国林业科学研究院》2016年博士论文 论文类型：学位论文
【摘要】：蒿柳(Salix viminalis)属杨柳科(Salicaceae)柳属(Salix),为重要的河岸带先锋灌木树种。蒿柳具扦插易繁殖、生长速度快、适应性强、轮伐期短、矮林作业容易等特性,近年来主要运用于生物质能源开发、污水处理和重金属污染土壤的植物修复等方面,具有广阔的应用前景。我国蒿柳资源丰富,但是相关的研究工作尚未开展。近年来,随着人类活动的干扰,蒿柳资源正在遭到严重破坏,需要对其种质资源进行评价与保护;蒿柳为雌雄异株植物,研究雌雄株差异可以为育种、运用提供指导。因此,本研究以野生蒿柳为对象,采用SSR标记对蒿柳居群间、居群内、雌雄亚居群间及雌雄亚居群内的遗传变异进行分析,在此基础上对蒿柳雌雄株的耐热性差异及生长与防御差异进行评价。本研究旨在为蒿柳的遗传改良及种质资源保存提供理论基础,并为蒿柳雌株、雄株在生产实践中的选择性运用提供参考。主要研究结果如下:1.采用20对SSR引物,对额尔古纳河流域和西辽河流域的12个蒿柳居群的遗传变异进行分析。结果表明,蒿柳具有较高水平的遗传多样性(Na=16.45,He=0.7416)和中等水平的遗传分化(FST=0.0761)。贝叶斯聚类、邻接法聚类以及主成分分析可将12个居群分为两类,两流域各成一类。IBD分析显示,Nei’s遗传距离和FST/(1-FST)均与地理距离存在显著相关性(r=0.4398,p㩳0.00;r=0.4029,p㩳0.00),地理距离是影响群体结构的主要因子。此外,距离较近的3个居群ZD1、ZD2和ZD3的遗传分化较低。AMOVA显示,绝大多数(93.37%)遗传变异存在于居群内,仅6.63%存在于居群间,与遗传分化系数相一致。额尔古纳河流域蒿柳居群的遗传多样性和私有等位基因数高于西辽河流域,特别是TL、MDG2、ZD1和GH居群,这些居群是特殊种质资源遗传变异的重要来源,在保护时应优先考虑。2.采用上述20对SSR引物,对额尔古纳河流域和西辽河流域的5对蒿柳雌雄亚居群的遗传变异进行分析。结果显示,蒿柳雌亚居群的遗传多样性(Na=7.3100,He=0.7226)和雄亚居群的遗传多样性(Na=7.1200,He=0.7071)均较高,但雌雄亚居群间无显著差异。在不利环境条件下(西辽河流域),蒿柳雌雄亚居群的遗传多样性显著降低,但是雌雄亚居群间仍无显著差异。蒿柳亚居群间的分化水平中等(FST=0.0858),与amova分析结果一致:6%的遗传变异存在于亚居群间,94%存在于亚居群内。亚居群间的fst表明同一对雌雄亚居群无显著分化,伴随着雌雄亚居群间较高的历史基因流(m=0.73~1.26)。但是,雌雄亚居群间的近期基因流较低。因此,在就地保护过程中,适当的人工杂交和扦插移栽可促进远距离个体间的基因流。3.正常条件下,蒿柳雌雄株的大部分生理指标无显著差异。40℃/30℃(白天温度/晚上温度)胁迫7d后,蒿柳雌雄的净光合速率(pn)分别下降了54.43%和44.84%,但雄株的pn显著高于雌株。雌雄株光合作用差异主要由非气孔因素引起:雌雄株的核酮糖-1,5-二磷酸羧化酶(rubisco)活性分别下降了39.71%和31.52%,但雄株活性显著高于雌株。高温胁迫下蒿柳雌雄株?psii和retr显著降低,但雄株显著高于雌株;光化学淬灭(qp)和调节性能量耗散y(npq)无显著变化,非光化学淬灭(qn)显著降低,非调节性能量耗散y(no)显著升高,但雄株的qp、qn及y(npq)均高于雌株,y(no)低于雌株。类胡萝卜素(car)含量显著升高,雄株显著高于雌株。叶片电导率(ec)和超氧阴离子自由基(o2·-)产生速率显著上升,但雌株ec值和o2·-产生速率显著大于雄株。超氧化物歧化酶(sod)活性、过氧化氢酶(cat)活性、抗坏血酸过氧化物酶(asa-pod)活性显著上升,过氧化物酶(pod)活性显著下降,4种酶活性均为雄株显著高于雌株。脯氨酸(pro)含量、可溶性蛋白(sp)含量显著升高,雄株的渗透调节物质含量显著高于雌株。根据以上结果,高温胁迫下,雌株受伤害程度较严重,雄株具有较强的保护能力,能更好地适应高温环境。高温胁迫下,各生理指标的平均生理分化系数(vst)为21.69%,说明78.31%的生理变异存在于雌、雄无性系间。尽管雌雄株均具有较高的生理变异,但由于雄株的耐热性强于雌株,因此适当多选择雄株优树,有助于获得耐热性强的新种质,扩大蒿柳的运用范围。4.对蒿柳雌雄株生长期不同阶段(6月~10月)的生长与防御差异进行研究,结果显示:扦插初期(6月),雌雄株的株高和地径无显著差异;7月,雄株株高显著高于雌株,但雌雄株地径无显著差异;8月~9月,雄株的株高和地径显著高于雌株。雌雄株的生长差异可由光合作用差异解释:6月,蒿柳雌雄株的pn无显著差异;7~10月,雄株的pn显著高于雌株。雌雄株的气孔导度(gs)和胞间co2浓度(ci)无显著差异,说明雌雄株的光合作用差异由非气孔限制因素引起。6月,蒿柳雌雄株的chla、chlb和car无显著差异;7月~10月,3种光合色素含量均为雄株显著高于雌株。因此,光合色素含量是造成雌雄株光合差异的原因之一。6月~10月,蒿柳雌雄株的多酚和单宁含量均无显著差异。6月,雌雄株的SOD和苯丙氨酸解氨酶(PAL)无显著差异,雄株POD和多酚氧化酶(PPO)活性显著高于雌株;7月~10月,4种酶活性均为雄株显著高于雌株,表明雄株的防御能力强于雌株。由以上结果可知,7月~10月,蒿柳雌雄株的差异较稳定;蒿柳雄株生长速度快、防御能力强,可弥补天然群体中雄株数量少的不足,从而维持物种的稳定性。综合以上研究,蒿柳的遗传变异和生理变异主要存在于无性系间,但是在自然生长状态下雄株的生长速率大于雌株,具有较强防御能力,也具有较强的耐热性。从生理生化角度考虑,在育种工作中适当多选择雄株优树,有助于获得生长及抗性优良的新种质。
[Abstract]:Willow (Salix viminalis) is Salicaceae Salix (Salicaceae) (Salix), as an important pioneer riparian shrub species. Willow cuttings with easy propagation, fast growth, strong adaptability, short rotation coppice, easy and other characteristics, in recent years, mainly used in the development of biomass energy, sewage treatment and Phytoremediation of heavy metal contaminated soil and so on, and has broad application prospects. China is rich in willow resources, but the related research work has not been carried out. In recent years, along with the disturbance of human activities, willow resources are destroyed seriously, the need for evaluation and protection of its germplasm resources; willow is dioecious, can the research and the differences between male and female for breeding, used to provide guidance. Therefore, the research on wild willow as the object, using SSR markers of willow populations and within populations, and among sub populations and female male sub genetic variation within populations of Analysis and evaluation on the basis of willow male and female difference in heat tolerance and growth and defense differences. The purpose of this study is to provide a theoretical basis for willow genetic improvement and germplasm preservation, and willow female, male strain selective in the production practice by reference. The main research results are as follows: 1. using 20 pairs of SSR primers, the genetic variation of 12 populations of Eergu'Na willow river basin and the West Liaohe River Basin were analyzed. The results showed that the genetic diversity of willow has high levels of genetic differentiation (Na=16.45, He=0.7416) and middle level (FST=0.0761). Bayesian clustering, clustering method and principal component analysis of adjacency the 12 populations are divided into two categories, two basin into different categories of.IBD analysis showed that Nei s genetic distance and FST/ (1-FST) showed significant correlation with geographic distance (r=0.4398, 0; P? R=0.4029, P? 0), the geographical distance is affected The main factor of population structure. In addition, 3 populations of ZD1 distance and genetic differentiation of ZD2 and lower ZD3.AMOVA showed that the vast majority (93.37%) of genetic variation exists within populations, only 6.63% are Yu Juqun, consistent with the genetic differentiation coefficient. Genetic diversity in Eergu'Na River populations of willow and the private allele number higher than the West Liaohe River Basin, especially TL, MDG2, ZD1 and GH populations, these special populations is an important source of genetic variation in germplasm resources, protection of priority should be given to.2. by the 20 pairs of SSR primers for the Eergu'Na River Basin and the West Liaohe River Basin 5 of male and female willow sub populations groups were analyzed. The results show that willow female sub populations (Na=7.3100, He=0.7226) and male sub populations (Na=7.1200, He=0.7071) were higher, but no significant difference in male and female sub groups. In the adverse environment Under the condition of (West Liaohe basin), Koyanagi Xiong subpopulation genetic diversity decreased significantly, but no significant difference between male and female sub populations are still among populations. Willow Yaju populations differentiation medium level (FST=0.0858), is consistent with the results of AMOVA analysis: 6% of genetic variation existed among sub populations, 94% in Asia within populations. Among sub populations of FST showed the same pair of male and female subpopulations had no significant differentiation, with male and female sub groups in the history of gene flow is higher (m=0.73~1.26). However, male and female between the subpopulations of recent gene flow is relatively low. Therefore, in situ conservation in the process of the artificial hybridization and cutting transplanting can promote long-distance gene flow among individual.3. under normal conditions, most physiological indexes in willow male and female of.40 had no significant difference (/30 degree centigrade temperature during the day / night temperature) after 7d treatment, the net photosynthetic rate of the male and female light willow (PN) were decreased by 54.43% and 44.84%, but the male plant 鐨刾n鏄捐憲楂樹簬闆屾牚.闆岄泟鏍厜鍚堜綔鐢ㄥ樊寮備富瑕佺敱闈炴皵瀛斿洜绱犲紩璧，
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