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Volume 32 Issue 4
Sep.  2019
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Genetic Diversity of Eucalyptus cloeziana

  • Received Date: 2018-11-09
    Accepted Date: 2019-01-14
  • Objective To study the genetic diversity of Eucalyptus cloeziana for the purposes of germplasm conservation and breeding potential evaluation. Method Fourteen simple sequence repeats (SSR) markers were used to detect the variation in four main distribution areas of E. cloeziana. The locus polymorphism and population diversity were analyzed, the differentiation coefficient and genetic similarity among regions and the molecular variance components inter-and intra-regions were calculated. Cluster analysis was conducted based on genetic similarity. Result A total of 249 alleles were detected in 14 SSR markers, with an average of 18 alleles per marker. Based on all the markers, the Shannon's information index was 1.785 4, the observed heterozygosity was 0.510 0, and the expected heterozygosity was 0.788 2, indicating a high genetic diversity. The average coefficient of genetic differentiation among regions was 0.071 6, and the component of variance among populations in analysis of molecular variance (AMOVA) was only 6.8%. This indicated that the level of genetic differentiation was moderate and genetic variation mainly exists in populations. Unweighted pair group method with arithmetic (UPGMA) clustering analysis divided the four main distribution areas of E. cloeziana into two major categories:north and south. Conclusion The germplasm resource conservation should give priority to the areas with high diversity. The genetic diversity of E. cloeziana is high, and it has great potential for breeding.
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  • [1]

    Pry L D, Johnson L A S. A Classification of the Eucalypts[M]. Australia:Australian National University, 1971.
    [2]

    Keating W G, Bolza E. Characteristics, Properties and Uses of Timbers[M]. Australia:Northern Australia and the Pacific, 1982.
    [3] 王豁然.桉树生物学概论[M].北京:科学出版社, 2010.

    [4] 李昌荣, 项东云, 陈健波, 等.大花序桉木材基本密度的变异研究[J].中南林业科技大学学报, 2012, 32(6):158-162, 176.

    [5] 宋志姣, 杨合宇, 翁启杰, 等.细叶桉群体的遗传多样性和受选择位点[J].林业科学, 2016, 52(9):39-47.

    [6] 李昌荣, 熊涛, 陈东林, 等.粗皮桉种源遗传多样性SSR分析[J].南方农业学报, 2016, 47(1):7-12. doi: 10.3969/j:issn.2095-1191.2016.01.7

    [7] 邓紫宇, 项东云, 熊涛, 等.引种粗皮桉种源遗传多样性的RAPD与SSR分析[J].西北林学院学报, 2017, 32(1):131-136. doi: 10.3969/j.issn.1001-7461.2017.01.21

    [8]

    Turnbull J W. Provenance variation in Eucalyptus cloeziana F. Muell. Silvicultura[J]. Sao Paulo, 1983, 31:508-511.
    [9] 周维, 卢翠香, 杨中宁, 等.大花序桉种源幼林材木材力学性质研究[J].西南林业大学学报, 2014, 34(6):75-80.

    [10]

    Li C R, Weng Q J, Chen J B, et al. Genetic parameters for growth and wood mechanical properties in Eucalyptus cloeziana F. Muell[J]. New forests, 2016, 152(47):1-17.
    [11] 周维, 李昌荣, 陈健波, 等.大花序桉种源遗传变异及适应性研究[J].西南林业大学学报, 2014, 34(4):36-41. doi: 10.3969/j.issn.2095-1914.2014.04.007

    [12]

    Turnbull J W. Geographic variation in Eucalyptus cloeziana F.Muell[J]. Oncogene, 1979, 32(41):4927-4931.
    [13]

    Zhou C P, He X D, Li F G, et al. Development of 240 novel EST-SSRs in Eucalyptus L'Hérit[J]. Molecular Breeding, 2014, 33(1):221-225. doi: 10.1007/s11032-013-9923-z
    [14] 周长品, 李发根, 翁启杰, 等. PCR产物直接测序和混合克隆测序进行桉树EST-SSR标记开发[J].分子植物育种(网络版), 2010, 8(1):1-10.

    [15]

    He X D, Wang Y, Li F G, et al. Development of 198 novel EST-derived microsatellites in Eucalyptus (Myrtaceae)[J]. American Journal of Botany, 2012, 99(4):e134-e148. doi: 10.3732/ajb.1100442
    [16]

    Broundanir P V, Williams E R, Brondani C, et al. A microsatellite-based consensus linkage map for species of Eucalyptus and a novel set of 230 microsatellite markers for the genus[J]. BMC Plant Biology, 2006, 6(1):1-16.
    [17]

    Li F G, Gan S M. An optimized protocol for fluorescent-dUPT based SSR genotyping and its application to genetic mapping in Eucalyptus[J]. Silvae Genetica, 2011, 60(1):18-25.
    [18] 李金花, 俞宁.利用荧光SSR标记分析中国油橄榄品种遗传多样性[J].林业科学, 2012, 48(6):47-55.

    [19]

    Nei M. Analysis of gene diversity in subdivided populations[J]. Proceedings of the National Academy of Sciences of the United States of America, 1973, 70(12):3321-3323. doi: 10.1073/pnas.70.12.3321
    [20]

    Rohlf J F. NTSYS pc: Numerical taxonomy and mulitivariate analysis system. Version 2.1, users guide. New York: Exeter software, setauket, 2000.
    [21]

    Steane D A, Potts B M, Mclean E, et al. A comparative analysis of population structure of a forest tree, Eucalyptus globules(Myrtaceae), using microsatellite markers and quantitative traits[J]. Tree Genetics & Genomes, 2006, 2(1):30-38.
    [22]

    Payn K G, Dvorak W S, Janse B J H, et al. Microsatellite diversity and genetic structure of the commercially important tropical tree species Eucalyptus urophylla, endemic to seven islands in eastern Indonesia[J]. Tree Genetics & Genomes, 2008, 4(3):519-530.
    [23]

    Mervyn S, Timothy R S, Dane T, et al. Geographical and historical determinants of microsatellite variation in Eucalyptus pilularis[J]. Canadian Journal of Forest Research, 2010, 40(6):1051-1063. doi: 10.1139/X10-049
    [24]

    Bradbury D, Smithson A, Krauss S L. Signatures of diversifying selection at EST-SSR loci and association with climate in natural Eucalyptus populations[J]. Molecular Ecology, 2013, 22(20):5112-5129. doi: 10.1111/mec.12463
    [25]

    Elliott C P, Byrne M. Genetic diversity within and between natural populations of Eucalyptus occidentalis (Myrtaceae)[J]. Silvae Genetica, 2003, 52(3-4):169-173.
    [26] 刘强, 尹翔, 杨艳, 等.白檀自然群居遗传结构与遗传多样性研究[J].植物遗传资源学报, 2015, 16(4):751-758.

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Genetic Diversity of Eucalyptus cloeziana

  • Guangxi Forestry Research Institute, Key Laboratory of Central South Fast-growing Timber Cultivation of National Forestry and Grassland Administration, Guangxi Key Laboratory of Superior Timber Trees Resource Cultivation, Nanning 530002, Guangxi, China

Abstract:  Objective To study the genetic diversity of Eucalyptus cloeziana for the purposes of germplasm conservation and breeding potential evaluation. Method Fourteen simple sequence repeats (SSR) markers were used to detect the variation in four main distribution areas of E. cloeziana. The locus polymorphism and population diversity were analyzed, the differentiation coefficient and genetic similarity among regions and the molecular variance components inter-and intra-regions were calculated. Cluster analysis was conducted based on genetic similarity. Result A total of 249 alleles were detected in 14 SSR markers, with an average of 18 alleles per marker. Based on all the markers, the Shannon's information index was 1.785 4, the observed heterozygosity was 0.510 0, and the expected heterozygosity was 0.788 2, indicating a high genetic diversity. The average coefficient of genetic differentiation among regions was 0.071 6, and the component of variance among populations in analysis of molecular variance (AMOVA) was only 6.8%. This indicated that the level of genetic differentiation was moderate and genetic variation mainly exists in populations. Unweighted pair group method with arithmetic (UPGMA) clustering analysis divided the four main distribution areas of E. cloeziana into two major categories:north and south. Conclusion The germplasm resource conservation should give priority to the areas with high diversity. The genetic diversity of E. cloeziana is high, and it has great potential for breeding.

  • 大花序桉(Eucalyptus. cloeziana F. Muell.)为桉属昆士兰桉亚属(Idiogenes L.D.Pryor & L.A.S.Johnson ex Brooker)树种,自然分布仅限于澳大利亚昆士兰州4个不连续的地理分布区,其木材黄褐色、材质重硬、纹理通直、具黑金条纹,是很好的锯材树种[1-3]。我国引种大花序桉始于1972年,生长较迅速,材质优良,如17年生大花序桉平均基本密度达0.706 g·cm-3[4],目前已在广西和福建等地广泛用于实木用材林的营建。

    遗传多样性是生态系统多样性和物种多样性的基础,研究一个物种的遗传多样性有助于理解其遗传变异水平及其在不同分布区的分化。分子标记是以DNA多态性为基础的遗传标记,广泛用作遗传多样性研究的手段,其中,简单重复序列(SSR)标记具有共显性、多态性高、重复性好等优点,已应用于细叶桉(E. tereticornis Smith)[5]、粗皮桉(E. pellita F. Muell.)[6-7]等桉属树种的遗传多样性研究。对于大花序桉,国外学者曾利用同工酶进行了种源的遗传多样性分析[8],近几年也利用木材力学性质[9-10]、生长和适应性[11]等表型性状进行遗传变异研究,但基于DNA水平的遗传多样性鲜见报道。本研究利用SSR标记对大花序桉4个主要分布地区进行了遗传多样性分析,旨在揭示大花序桉群体的遗传变异规律和遗传分化水平,以期为遗传资源的保存和育种潜力的评估提供理论基础。

1.   试验材料
  • 试验材料基于广西壮族自治区林业科学研究院引种的大花序桉种源/家系试验林,试验育苗的种子采自澳大利亚昆士兰州4个主要分布地区[12]的119株母树(半同胞家系)(表 1),每株母树(家系)选取1株子代采集嫩叶。

    起源地区
    Original region
    纬度(S)
    Latitude
    经度(E)
    Longitude
    家系数量/个
    Family number
    北部沿海
    Northern coastal
    15°~20° 145°~147° 41
    北部内陆
    Northern inland
    17°~18° 145°~146° 17
    南部内陆
    Southern inland
    25°~26° 150°~152° 7
    南部近沿海
    Southern subcoastal
    25°~27° 152°~153° 54

    Table 1.  Original locality of E.cloeziana samples tested

2.   研究方法
  • 大花序桉DNA提取采用天根生化科技(北京)有限公司的植物基因组DNA提取试剂盒,用1.5%琼脂糖凝胶电泳检测其浓度和质量。从已发表的桉树SSR标记中筛选出多态性较好的14个(表 2)用于本研究,包括Zhou等(标记序号1~8)[13]、周长品等(标记序号9和10)[14]、He等(标记序号11)[15]、Brondani等(标记序号12~14)[16]。SSR标记的检测方法参照文献[17],PCR产物利用ABI3130xl遗传分析仪(Applied Biosystems,美国)检测。

    序号
    No.
    SSR标记
    SSR marker
    前向引物序列
    Forward primer sequence(5′-3′)
    后向引物序列
    Reverse primer sequence(5′-3′)
    1 EUCeSSR0294n TGCTGATGTTCCCGCCTAC GGAAGCAAATCATCCAGCAC
    2 EUCeSSR0952 AAAAGCAGAGCGACAGCG TTCGGCCATAAACCATCC
    3 EUCeSSR1145n2 GGCCGGGGACAGAAACTC TGCTACGGGAGCGAAACC
    4 EUCeSSR0850 TAAACTCCATTCTCCTCCAA CGTGAACCCACATTGCTC
    5 EUCeSSR0035n GCTCCCTCCTGCGAGATTT CGCCGATGATGATGTACTTGAA
    6 EUCeSSR0620 CCGCACTCCAAGGACCACA CAGTAGCCGCTGCTCAAA
    7 EUCeSSR0599 CCGAGAAACGCAGGATGT CGGCGGAGTCGTAGGAAGT
    8 EUCeSSR0276n GATGGTTGCCAGATGACT TCTCATCTCATCATTCACTAAA
    9 EUCeSSR0984 TCTTACGCACCGTCCTCT AGCCATTTCGCTCCTTCC
    10 EUCeSSR1087n AGGCACAACAAGGTAAAGC GAGGGCCAATCTAGCATC
    11 EUCeSSR712 CATTCCTCCGAGCATTTCC GCGACAACAACGGAGACAA
    12 Embra8 CACAACTAAAAATCAAAACCC AAAGAGCAGATTATTACAGAAGC
    13 Embra40 AAAGTATCTTCACGCTTCAT TCCCAATCATGATCTTCAG
    14 Embra100 TGTGTTCTCGGTTTCAAAACT TGTGAAGTGATGCGAAGC

    Table 2.  SSR markers and their primer sequences

  • 利用软件GeneMarker V1.95[18]读取SSR标记数据,利用软件POPGEN1.31[19]计算各参数,利用软件NTSYSpc2.1[20]构建聚类树状图。

3.   结果与分析
  • 14个SSR标记的多态性参数(表 3)表明:14个SSR标记共检测到249个等位片段,平均每个标记的等位片段为18个,其中,最多的标记(EUCeSSR0850)为24个,最少的标记(EUCeSSR0952)为6个;有效等位片段数为1.972 5~11.265 4,平均为6.959 6;Shannon′s信息指数为0.991 7~2.709 3,平均为2.159 7;Nei′s遗传多样性指数为0.493 0~0.911 2,平均为0.822 3;观测杂合度为0.273 5~0.769 2,平均为0.508 3;期望杂合度为0.495 1~0.915 1,平均为0.825 8。

    SSR位点
    SSR locus
    等位片段数(Na)
    Number of
    alleles
    有效等位片段数(Ne)
    Effective number
    of alleles
    观测杂合度(Ho)
    Observed
    heterozygosity
    期望杂合度(He)
    Expected
    heterozygosity
    Shannon′s信息指数(I)
    Shannon′s information
    index
    Nei′s遗传多样性
    指数(H)
    Nei′s gene diversity
    EUCeSSR0294n 23 10.137 6 0.466 1 0.905 2 2.545 4 0.901 4
    EUCeSSR0952 6 1.972 5 0.769 2 0.495 1 0.991 7 0.493 0
    EUCeSSR1145n2 22 7.915 9 0.567 8 0.877 4 2.409 2 0.873 7
    EUCeSSR0850 24 11.265 4 0.508 5 0.915 1 2.709 3 0.911 2
    EUCeSSR0035n 11 4.660 1 0.487 2 0.788 8 1.758 9 0.785 4
    EUCeSSR0620 18 5.274 1 0.273 5 0.813 9 2.021 6 0.810 4
    EUCeSSR0599 17 5.302 4 0.440 7 0.814 9 2.064 7 0.811 4
    EUCeSSR0276n 22 5.221 8 0.516 9 0.811 9 2.064 3 0.808 5
    EUCeSSR0984 7 3.536 7 0.415 3 0.720 3 1.443 1 0.717 3
    EUCeSSR1087n 14 8.027 7 0.627 1 0.879 2 2.243 2 0.875 4
    EUCeSSR712 22 8.926 0 0.603 4 0.891 8 2.551 2 0.888 0
    Embra8 23 6.982 9 0.550 8 0.860 4 2.396 6 0.856 8
    Embra40 21 8.426 0 0.542 4 0.885 1 2.509 3 0.881 3
    Embra100 19 9.785 0 0.347 5 0.901 6 2.527 9 0.897 8
    均值
    Mean
    18 6.959 6 0.508 3 0.825 8 2.159 7 0.822 3

    Table 3.  Diversity parameters of the 14 SSR loci analyzed

  • 大花序桉4个主要分布区的遗传多样性参数(表 4)表明:等位片段数为5.071 4~12.642 9,平均为9.982 1;有效等位片段数为3.751 6~6.526 7,平均为5.267 8;Shannon′s信息指数为1.404 2~1.966 4,平均为1.785 4;Nei′s遗传多样性指数为0.697 4~0.795 7,平均为0.761 8;观测杂合度为0.500 0~0.530 4,平均为0.510 0;期望杂合度为0.760 8~0.821 4,平均为0.788 2,表明各地区的多样性水平较高。大花序桉4个地区的遗传多样性参数存在差异,北部地区各参数值相对较大,可能是起源中心。

    起源地区
    Original region
    等位片
    段数(Na)
    Number of
    alleles
    有效等位片
    段数(Ne)
    Effective number
    ofalleles
    观测杂
    合度(Ho)
    Observed
    heterozygosity
    期望杂
    合度(He)
    Expected
    heterozygosity
    Shannon′s信息
    指数(I)
    Shannon′s
    information index
    Nei′s遗传多样性
    指数(H)
    Nei′s gene
    diversity
    北部沿海
    Northern coastal
    12.642 9 6.044 2 0.502 6 0.793 2 1.966 4 0.783 7
    北部内陆
    Northern inland
    9.857 1 6.526 7 0.530 4 0.821 4 1.930 0 0.795 7
    南部内陆
    Southern inland
    5.071 4 3.751 6 0.500 0 0.760 8 1.404 2 0.697 4
    南部近沿海
    Southern subcoastal
    12.357 1 4.748 5 0.507 0 0.777 5 1.841 1 0.770 3
    均值
    Mean
    9.982 1 5.267 8 0.510 0 0.788 2 1.785 4 0.761 8

    Table 4.  Genetic diversity parameters for the four original regions of E.cloeziana

  • 大花序桉4个主要分布区的遗传分化系数和基因流(表 5)表明:地区间遗传分化系数为0.025 8~0.106 7,平均为0.071 6;基因流为2.092 0~9.423 0,平均为3.242 9,说明大花序桉具有中等的遗传分化,且基因流动程度相对较高。

    SSR位点
    SSR locus
    地区内近交系数
    Inbreeding coefficients of individuals
    relative to the sub-region(Fis)
    地区间近交系数
    Inbreeding coefficients of individuals
    relative to the total region(Fit)
    地区间分化系数
    Between-region
    differentiation(Fst)
    基因流
    Number of
    migrants(Nm)
    EUCeSSR0294n 0.357 7 0.396 8 0.060 9 3.852 9
    EUCeSSR0952 0.526 7 0.547 1 0.043 2 5.537 9
    EUCeSSR1145n2 0.488 6 0.517 1 0.055 7 4.236 5
    EUCeSSR0850 0.394 9 0.429 1 0.056 5 4.176 2
    EUCeSSR0035n 0.289 8 0.324 1 0.048 3 4.928 5
    EUCeSSR0620 0.137 9 0.196 7 0.068 2 3.413 1
    EUCeSSR0599 0.162 7 0.252 0 0.106 7 2.092 0
    EUCeSSR0276n 0.411 0 0.426 3 0.025 8 9.423 0
    EUCeSSR0984 0.158 8 0.248 3 0.106 4 2.099 5
    EUCeSSR1087n 0.602 4 0.619 1 0.041 8 5.726 9
    EUCeSSR712 0.394 1 0.453 3 0.097 6 2.312 2
    Embra8 0.358 8 0.409 6 0.079 2 2.907 4
    Embra40 0.445 4 0.503 1 0.103 9 2.156 3
    Embra100 0.228 3 0.303 8 0.097 8 2.305 0
    均值
    Mean
    0.355 4 0.401 6 0.071 6 3.242 9

    Table 5.  Coefficient of genetic differentiation and gene flow between E. cloeziana original regions

    分子方差(AMOVA) (表 6)表明:大部分遗传变异发生在地区内(93.2%),地区间方差分量仅占6.8%,表明大花序桉的群体结构较弱,群体间遗传分化不明显。

    变异来源
    Source of variation
    自由度
    Degrees of freedom
    平方和
    Sum of squares
    方差分量
    Variance component
    方差分量比
    Ratio of variance/%
    地区间
    Among regions
    3 92.4 0.440 4 6.8
    地区内个体间
    Among individuals within regions
    115 944.5 2.266 3 35.5
    个体间
    Within individuals
    119 438.0 3.680 7 57.7
    总计
    Total
    237 1 474.9 6.387 3 100.0

    Table 6.  AMOVA results for within-and among-region variations in E. cloeziana

    4个地区间的遗传一致度和遗传距离(表 7)表明:遗传一致度为0.649 8~0.896 1,平均为0.717 2;遗传距离为0.109 8~0.431 0,平均为0.338 9。基于遗传一致度,利用非加权分组算术平均(UPGMA)法进行聚类分析(图 1)表明:遗传一致度为0.74时,大花序桉4个主要分布区被划分为北部亚类和南部亚类。

    Figure 1.  UPGMA clustering of four E. cloeziana original regions

    起源地区
    Original region
    北部沿海
    Northern coastal
    北部内陆
    Northern inland
    南部内陆
    Southern inland
    南部近沿海
    Southern subcoastal
    北部沿海
    Northern coastal
    0.896 1 0.675 9 0.649 8
    北部内陆
    Northern inland
    0.109 8 0.669 0 0.665 9
    南部内陆
    Southern inland
    0.391 7 0.402 0 0.746 4
    南部近沿海
    Southern subcoastal
    0.431 0 0.406 6 0.292 5
    注:对角线上方为遗传一致度,对角线下方为遗传距离。
    Note: The genetic identity was above the diagonal, and the genetic distance was below the diagonal.

    Table 7.  Nei′s genetic identity and genetic distance between E. cloeziana original regions

4.   讨论
  • 大花序桉的遗传多样性水平较高,平均期望杂合度为0.788 2,与基于SSR分析的大部分桉属树种的遗传多样性水平相似,如蓝桉(E. globulus Labill.)[21]、尾叶桉(E. urophylla S. T. Blake)[22]、弹丸桉(E. pilularis Smith)[23]、棒头桉(E. gomphocephala S. T. Blake)[24]、细叶桉[5]、粗皮桉[6]等的平均期望杂合度分别为0.820、0.739、0.780、0.750、0.800、0.678。大花序桉自然分布仅限昆士兰州,但其有效群体较大,自然群体以随机异交为主,这是大花序桉和大部分桉属树种遗传多样性水平较高的主要原因。此外,地区或群体取样量一定程度上影响多样性水平,如本研究中南部内陆地区仅7株样品, 期望杂合度(0.760 8,表 4)低于其他3个地区,但仅稍低于样品量为54的南部近沿海地区(He=0.777 5,表 4);在西方桉(E. occidentalis Endl.)[25]研究中,部分群体取样量少于10株仍有效地分析了群体多样性。

  • 大花序桉的遗传分化系数平均为0.071 6,分化度不高,类似于蓝桉[21],显著高于细叶桉[5]、粗皮桉[6]和尾叶桉[22]。大花序桉基因流平均为3.242 9,表明有较频繁的基因交流,也是遗传分化水平不高的原因。频繁的基因交流有助于维持群体稳定,一定程度上增强群体对环境变化的适应性[26]。AMOVA分析发现,大花序桉的地区内和地区间均存在显著的遗传变异,群体内变异远大于群体间变异,这与利用SSR分析的其他桉树树种的遗传变异特点相似。本研究的遗传材料涵盖了大花序桉的4个自然分布区,虽然北部与南部分布区不连续,但有效群体较大和异交交配系统可能是遗传分化水平不高的主要原因。

    聚类分析中,北部沿海地区和北部内陆地区被聚为一亚类,南部内陆地区和南部近沿海地区被聚为另一亚类,表明地理位置较近、气候条件相似的群体遗传相似性较高而被聚为一亚类,这也与粗皮桉[6]的群体聚类结果一致。

  • 大花序桉的遗传多样性丰富,表明进一步选择和育种利用的潜力较好;其遗传变异93.2%存在于主要分布区内,表明在今后种质保存和核心群体构建工作中应充分重视地区内相当数量家系的保存,并且家系较少的地区需要补充新的种质资源,以提高育种群体的遗传变异水平。北部沿海地区遗传多样性较高,是选择和育种需要重点利用的材料;北部沿海与北部内陆之间的遗传距离相对较小,北部内陆可重视特有等位片段材料的保存和利用;北部沿海和南部近沿海之间的遗传距离相对较大,可能产生较大的种内杂交优势,在今后控制授粉的亲本选配时可重视这两个地区的优良家系/单株。当然,分子水平变异可能与表型变异存在差异[21],尤其是林木表型易受环境影响,因此,分子水平的变异对经济性状表现的影响仍待进一步的种源/家系试验进行检测,杂交亲本的选配和种子园优良亲本的选用更多地需要基于常规育种的表型选择。

5.   结论
  • 本文利用SSR标记较系统地分析了大花序桉4个主要天然分布区的遗传多样性和遗传分化,有助于大花序桉种质资源的保存和育种利用的策略定制。大花序桉的遗传多样性较高,育种的利用潜力较大,种质资源保存应重视多样性较高地区的材料;大花序桉的遗传分化水平中等,遗传变异主要来源于地区内,但地区间仍存在较大程度的基因流,选择育种可重视多样性较高的地区内家系/单株的选择。今后应结合表型变异检测分子变异对表型选择的可能影响。

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