本文關鍵詞：蒿柳居群、雌雄亞居群遺傳多樣性及雌雄株生理差異　出處：《中國林業(yè)科學研究院》2016年博士論文　論文類型：學位論文

  更多相關文章： 蒿柳 性別差異 遺傳變異 生理變異 耐熱性

【摘要】：蒿柳(Salix viminalis)屬楊柳科(Salicaceae)柳屬(Salix),為重要的河岸帶先鋒灌木樹種。蒿柳具扦插易繁殖、生長速度快、適應性強、輪伐期短、矮林作業(yè)容易等特性,近年來主要運用于生物質(zhì)能源開發(fā)、污水處理和重金屬污染土壤的植物修復等方面,具有廣闊的應用前景。我國蒿柳資源豐富,但是相關的研究工作尚未開展。近年來,隨著人類活動的干擾,蒿柳資源正在遭到嚴重破壞,需要對其種質(zhì)資源進行評價與保護;蒿柳為雌雄異株植物,研究雌雄株差異可以為育種、運用提供指導。因此,本研究以野生蒿柳為對象,采用SSR標記對蒿柳居群間、居群內(nèi)、雌雄亞居群間及雌雄亞居群內(nèi)的遺傳變異進行分析,在此基礎上對蒿柳雌雄株的耐熱性差異及生長與防御差異進行評價。本研究旨在為蒿柳的遺傳改良及種質(zhì)資源保存提供理論基礎,并為蒿柳雌株、雄株在生產(chǎn)實踐中的選擇性運用提供參考。主要研究結(jié)果如下:1.采用20對SSR引物,對額爾古納河流域和西遼河流域的12個蒿柳居群的遺傳變異進行分析。結(jié)果表明,蒿柳具有較高水平的遺傳多樣性(Na=16.45,He=0.7416)和中等水平的遺傳分化(FST=0.0761)。貝葉斯聚類、鄰接法聚類以及主成分分析可將12個居群分為兩類,兩流域各成一類。IBD分析顯示,Nei’s遺傳距離和FST/(1-FST)均與地理距離存在顯著相關性(r=0.4398,p㩳0.00;r=0.4029,p㩳0.00),地理距離是影響群體結(jié)構(gòu)的主要因子。此外,距離較近的3個居群ZD1、ZD2和ZD3的遺傳分化較低。AMOVA顯示,絕大多數(shù)(93.37%)遺傳變異存在于居群內(nèi),僅6.63%存在于居群間,與遺傳分化系數(shù)相一致。額爾古納河流域蒿柳居群的遺傳多樣性和私有等位基因數(shù)高于西遼河流域,特別是TL、MDG2、ZD1和GH居群,這些居群是特殊種質(zhì)資源遺傳變異的重要來源,在保護時應優(yōu)先考慮。2.采用上述20對SSR引物,對額爾古納河流域和西遼河流域的5對蒿柳雌雄亞居群的遺傳變異進行分析。結(jié)果顯示,蒿柳雌亞居群的遺傳多樣性(Na=7.3100,He=0.7226)和雄亞居群的遺傳多樣性(Na=7.1200,He=0.7071)均較高,但雌雄亞居群間無顯著差異。在不利環(huán)境條件下(西遼河流域),蒿柳雌雄亞居群的遺傳多樣性顯著降低,但是雌雄亞居群間仍無顯著差異。蒿柳亞居群間的分化水平中等(FST=0.0858),與amova分析結(jié)果一致:6%的遺傳變異存在于亞居群間,94%存在于亞居群內(nèi)。亞居群間的fst表明同一對雌雄亞居群無顯著分化,伴隨著雌雄亞居群間較高的歷史基因流(m=0.73~1.26)。但是,雌雄亞居群間的近期基因流較低。因此,在就地保護過程中,適當?shù)娜斯るs交和扦插移栽可促進遠距離個體間的基因流。3.正常條件下,蒿柳雌雄株的大部分生理指標無顯著差異。40℃/30℃(白天溫度/晚上溫度)脅迫7d后,蒿柳雌雄的凈光合速率(pn)分別下降了54.43%和44.84%,但雄株的pn顯著高于雌株。雌雄株光合作用差異主要由非氣孔因素引起:雌雄株的核酮糖-1,5-二磷酸羧化酶(rubisco)活性分別下降了39.71%和31.52%,但雄株活性顯著高于雌株。高溫脅迫下蒿柳雌雄株?psii和retr顯著降低,但雄株顯著高于雌株;光化學淬滅(qp)和調(diào)節(jié)性能量耗散y(npq)無顯著變化,非光化學淬滅(qn)顯著降低,非調(diào)節(jié)性能量耗散y(no)顯著升高,但雄株的qp、qn及y(npq)均高于雌株,y(no)低于雌株。類胡蘿卜素(car)含量顯著升高,雄株顯著高于雌株。葉片電導率(ec)和超氧陰離子自由基(o2·-)產(chǎn)生速率顯著上升,但雌株ec值和o2·-產(chǎn)生速率顯著大于雄株。超氧化物歧化酶(sod)活性、過氧化氫酶(cat)活性、抗壞血酸過氧化物酶(asa-pod)活性顯著上升,過氧化物酶(pod)活性顯著下降,4種酶活性均為雄株顯著高于雌株。脯氨酸(pro)含量、可溶性蛋白(sp)含量顯著升高,雄株的滲透調(diào)節(jié)物質(zhì)含量顯著高于雌株。根據(jù)以上結(jié)果,高溫脅迫下,雌株受傷害程度較嚴重,雄株具有較強的保護能力,能更好地適應高溫環(huán)境。高溫脅迫下,各生理指標的平均生理分化系數(shù)(vst)為21.69%,說明78.31%的生理變異存在于雌、雄無性系間。盡管雌雄株均具有較高的生理變異,但由于雄株的耐熱性強于雌株,因此適當多選擇雄株優(yōu)樹,有助于獲得耐熱性強的新種質(zhì),擴大蒿柳的運用范圍。4.對蒿柳雌雄株生長期不同階段(6月~10月)的生長與防御差異進行研究,結(jié)果顯示:扦插初期(6月),雌雄株的株高和地徑無顯著差異;7月,雄株株高顯著高于雌株,但雌雄株地徑無顯著差異;8月~9月,雄株的株高和地徑顯著高于雌株。雌雄株的生長差異可由光合作用差異解釋:6月,蒿柳雌雄株的pn無顯著差異;7~10月,雄株的pn顯著高于雌株。雌雄株的氣孔導度(gs)和胞間co2濃度(ci)無顯著差異,說明雌雄株的光合作用差異由非氣孔限制因素引起。6月,蒿柳雌雄株的chla、chlb和car無顯著差異;7月~10月,3種光合色素含量均為雄株顯著高于雌株。因此,光合色素含量是造成雌雄株光合差異的原因之一。6月~10月,蒿柳雌雄株的多酚和單寧含量均無顯著差異。6月,雌雄株的SOD和苯丙氨酸解氨酶(PAL)無顯著差異,雄株POD和多酚氧化酶(PPO)活性顯著高于雌株;7月~10月,4種酶活性均為雄株顯著高于雌株,表明雄株的防御能力強于雌株。由以上結(jié)果可知,7月~10月,蒿柳雌雄株的差異較穩(wěn)定;蒿柳雄株生長速度快、防御能力強,可彌補天然群體中雄株數(shù)量少的不足,從而維持物種的穩(wěn)定性。綜合以上研究,蒿柳的遺傳變異和生理變異主要存在于無性系間,但是在自然生長狀態(tài)下雄株的生長速率大于雌株,具有較強防御能力,也具有較強的耐熱性。從生理生化角度考慮,在育種工作中適當多選擇雄株優(yōu)樹,有助于獲得生長及抗性優(yōu)良的新種質(zhì)。
[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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