PDF(2165 KB)
两个南方红豆杉天然居群的交配系统分析
罗芊芊, 李峰卿, 肖德卿, 邓章文, 王建华, 周志春
南京林业大学学报（自然科学版） ›› 2023, Vol. 47 ›› Issue (5) : 80-86.
PDF(2165 KB)
PDF(2165 KB)
两个南方红豆杉天然居群的交配系统分析
Mating system analyses of two natural populations of Taxus wallichiana var. mairei
【目的】研究南方红豆杉(Taxus wallichiana var. mairei)天然居群的交配系统,揭示浙江龙泉和江西分宜天然居群的交配机制以及亲代间的遗传多样性差异,为南方红豆杉的科学保育和遗传资源有效利用提供理论参考。【方法】以浙江龙泉和江西分宜天然居群亲代及其子代为研究对象,运用12对SSR引物对71个亲代及8个采种母株的104个子代进行分析。【结果】参试的浙江龙泉和江西分宜居群亲代的等位基因数(Na)皆为7,2个参试居群的有效等位基因数(Ne)分别为4.831和3.552,浙江龙泉居群较江西分宜居群高出1.279个有效等位基因。2个参试居群的观测杂合度(Ho)均小于期望杂合度(He),且固定指数(F)大于0。浙江龙泉居群的等位基因丰富度和私有等位基因丰富度(AR=4.195,PA=1.832)皆大于江西分宜居群(AR=3.576,PA=1.647)。2个参试居群的遗传多样性略有差异,但仍具有较高的遗传多样性。多位点交配系统分析(MLTR)结果表明,浙江龙泉和江西分宜居群中,南方红豆杉的异交率较高(tm=1.200)。单位点和多位点父本相关性的差值[rp(s)-rp(m)]为0.095,亲代居群内存在近交现象,但近交水平较低( =0.268)。有效花粉供体(Nep=1.5)数目较少,表明南方红豆杉自然交配时亲本(父本)来源非常有限。【结论】南方红豆杉属于高度异交树种,2个参试居群的异交率差异不明显且遗传多样性皆较高,居群内存在近交现象,但近交水平较低。
【Objective】 The objective of this study is to examine the mating system of Taxus wallichiana var. mairei in natural populations located in Longquan City from Zhejiang Province and Fenyi City from Jiangxi Province. Furthermore, the study aims to elucidate the influence of mating mechanisms and variances in parental genetic diversity, to provide a theoretical basis for the scientific conservation and efficient utilization of the genetic resources of T. wallichiana var. mairei. 【Method】 A total of 71 parental plants and 104 progenies stemming from eight mother plants were meticulously analyzed using 12 pairs of the SSR primers, all of which were sourced from natural populations located in Longquan of Zhejiang Province (ZJLQ) and Fenyi of Jiangxi Province (JXFY). With the aid of GenAlEx 6.5, a number of genetic diversity measures such as the observed alleles and effective alleles, as well as observed heterozygosity, expected heterozygosity, Shannon index and fixed index were meticulously calculated. Furthermore, the team also utilized HP-Rare 1.1 to calculate allele richness and private allele richness, while FSTAT 2.9.3 was utilized to test the genetic diversity parameters for any potential differences among parents within each population through 1 000 simulations, along with the calculation of the inbreeding coefficient of the parental population. Lastly, we used MLTR 3.4 to estimate thoroughly the genetic parameters of T. wallichiana var. mairei’s mating system, which included single-locus population outcrossing rate, multilocus population outcrossing rate, number of effective pollen donors, multilocus correlation of paternity, singlelocus correlation of paternity, difference between the paternal correlation of single-locus and multilocus.【Result】 The average allele of the parental generation from Longquan and Fenyi populations was 7. Meanwhile, the effective allele number (Ne), Shannon index (I), allele richness (AR) and private allele richness (PA) of the two parental populations were 4.192, 1.508, 3.886 and 1.740, respectively. In comparison, the ZJLQ population displayed higher Ne, I, AR and PA values than the JXFY population, standing at 4.831, 1.620, 4.195 and 1.832, respectively. Both populations displayed an inbreeding coefficient greater than zero, with the ZJLQ population’s (Fis= 0.057) coefficient being significantly lower than that of the JXFY population (Fis= 0.171). Additionally, the observed heterozygosity (Ho) of the both populations was lower than that of the expected heterozygosity (He), with the fixed index (F) being greater than zero, indicating a loss of heterozygotes. The fixed index (F) of the ZJLQ population was 0.001, which did not differ from zero. The Longquan population exhibited higher values for both allele richness and private allele richness (AR= 4.195, PA= 1.832) in comparison to the Fenyi population (AR= 3.576, PA= 1.647). Despite a slight difference in the genetic diversity of the two populations, they both displayed high levels of genetic diversity. Results from the multi-locus mating system analysis (MLTR) revealed that the outcrossing rate of T. wallichiana var. mairei was higher (tm = 1.200) in the suitable populations of Longquan and Fenyi. Although the difference between paternal correlation of unit point and multilocus [rp(s) - rp(m)]equaled 0.095 and was greater than 0, indicating inbreeding in the parental population, the level of inbreeding was low (tm-ts = 0.268). The number of available pollen donors in both ZJLQ and JXFY populations was less than 2, and the paternal correlation and the number of effective pollen donors (Nep=1/rp(m)) were significantly different, suggesting that the parental sources were considerably limited during natural mating of T. wallichiana var. mairei. 【Conclusion】 T. wallichiana var. mairei is considered to be a highly outcrossing species, with both its single-locus population outcrossing rate and multilocus population outcrossing rate being high. However, there were no obvious differences in the outcrossing rate and genetic diversity between the two populations. Inbreeding was observed, but at low levels. The Longquan population is declining primarily due to the shortage of middle-aged and young plants and a high number of old trees. Despite the lower number of parental individuals in the ZJLQ population than the JXFY population, the former has a relatively high proportion of female individuals, which facilitates successful pollination rates and genetic exchange within the population. This advantageous characteristic results in the genetic diversity of the ZJLQ population not being inferior to that of the JXFY population. The Fenyi population has a larger number of young trees and seedlings, indicating that the habitat is suitable for the germination of T. wallichiana var. mairei seeds and the formation of seedlings. Therefore, with appropriate nurturing measures, this type of population has the potential to develop into an expanding population.
南方红豆杉 / 天然居群 / 交配系统 / 亲代 / 子代 / 微卫星DNA
Taxus wallichiana var. mairei / natural population / mating system / parental generation / progeny / microsatellite(SSR)
| [1] |
|
| [2] |
陈立新, 华波, 彭宝珠, 等. 南方红豆杉人工授粉与雌雄同株现象研究[J]. 现代农业科技, 2013(11):181,183.
|
| [3] |
费永俊, 刘志雄, 王祥, 等. 南方红豆杉响应不同传粉式样的结实表现[J]. 西北植物学报, 2005, 25(3):478-483.
|
| [4] |
李先琨, 向悟生, 欧祖兰, 等. 濒危植物南方红豆杉种群克隆生长空间格局与动态[J]. 云南植物研究, 2003, 25(6):625-632.
|
| [5] |
罗芊芊, 周志春, 邓宗付, 等. 南方红豆杉天然居群叶片的表型性状和氮磷化学计量特征的变异规律[J]. 植物资源与环境学报, 2021, 30(1):27-35.
|
| [6] |
孙启武, 王磊, 张小平, 等. 皖南山区南方红豆杉种群动态研究[J]. 林业科学研究, 2009, 22(4):579-585.
|
| [7] |
高润梅, 石晓东, 樊兰英, 等. 山西省南方红豆杉自然分布与群落生态学特征[J]. 应用生态学报, 2016, 27(6):1820-1828.
|
| [8] |
王敏求, 武星彤, 王利宝, 等. 南方红豆杉群体基因流比较分析[J]. 分子植物育种, 2019, 17(19):6269-6275.
|
| [9] |
|
| [10] |
张志权, 廖文波, 钟翎, 等. 南方红豆杉种子萌发生物学研究[J]. 林业科学研究, 2000, 13(3):280-285.
|
| [11] |
张艳杰, 高捍东, 鲁顺保. 南方红豆杉种子中发芽抑制物的研究[J]. 南京林业大学学报(自然科学版), 2007, 31(4):51-56.
|
| [12] |
肖遥, 张蕊, 楚秀丽, 等. 24个产地南方红豆杉在两试验点的生长差异及其选择[J]. 林业科学研究, 2017, 30(2):342-348.
|
| [13] |
罗芊芊, 楚秀丽, 李峰卿, 等. 5年生南方红豆杉生长和分枝性状家系变异与选择[J]. 林业科学研究, 2020, 33(1):136-143.
|
| [14] |
鲁定伟, 周要全, 李曙波, 等. 南方红豆杉生物学、生态学特性及培育技术[J]. 经济林研究, 2014, 32(4):159-164.
|
| [15] |
姚甲宝, 袁小军, 周新华, 等. 南方红豆杉2年生容器苗育苗方案优选[J]. 东北林业大学学报, 2019, 47(11):11-16.
|
| [16] |
Reproductive ecology of Agalinis acuta was investigated by examining potential for self‐fertilization before and at anthesis, reproductive output from outcrossed vs. selfed matings, and effects of browsing, plant size, and conspecific plant density on seed and fruit production. These features of a plant species can provide indirect information pertinent to conservation such as patterns and maintenance of genetic diversity, risk associated with inbreeding depression, and changes in pollinator abundance or effectiveness. The species is self‐compatible, with 97% of selfed flowers setting fruit; pollinators were not required for reproduction. However, seed set in self‐pollinated fruits averaged 17–20% less than that in open‐pollinated fruits. Geitonogamous and facilitated selfing are possible throughout anthesis and autonomous selfing is possible late in anthesis as corollas abscise. Delaying self‐pollination until after outcrossing opportunities likely limits selfing rates and thus reduces risks associated with inbreeding but allows reproduction in absence of pollinators. Supplementing pollen on open‐pollinated flowers yielded no additional seed set over controls. Neither early‐season browsing of primary stems nor conspecific plant density had significant effects on number of fruits per plant, on fruit size, or on number of seeds from open‐pollinated flowers. Currently, reproduction appears to be high (about 2400 seeds/plant), and future risks due to lack of genetic diversity are likely low.
|
| [17] |
|
| [18] |
|
| [19] |
赖焕林, 王章荣, 陈天华. 林木群体交配系统研究进展[J]. 世界林业研究, 1997, 10(5):10-15.
|
| [20] |
徐刚标. 南方红豆杉濒危机制及保育技术[M]. 北京: 科学出版社, 2015:54-89.
|
| [21] |
|
| [22] |
易官美, 黎建辉, 王冬梅, 等. 南方红豆杉SSR分布特征分析及分子标记的开发[J]. 园艺学报, 2013, 40(3):571-578.
利用基因组勘测序列（GSS 序列）探讨开发南方红豆杉（Taxus wallichiana var. mairei）SSR标记的可行性。从1 923 条GSS 序列中搜寻到184 个SSR 位点。其中二核苷酸、三核苷酸和四核苷酸重复所占比例分别为88.6%、10.3%和1.1%。不同核苷酸在重复序列中的频率分析表明，a 和t 所出现的频率远远高于c 和g 的频率。对所获得的184 个SSR 位点设计引物，开发出90 个候选SSR 引物。在所获得的获选标记中选取20 对引物在南方红豆杉中进行试验检验，结果19 对（95%）SSR 引物能够获得清晰稳定的主带，表明GSS 序列可以高效地用于开发基因组SSR 标记，这些标记将为南方红豆杉的相关研究奠定基础。
|
| [23] |
程蓓蓓. 中国红豆杉属分子谱系地理学与遗传多样性研究[D]. 北京: 中国林业科学研究院, 2016.
|
| [24] |
Summary: GenAlEx: Genetic Analysis in Excel is a cross-platform package for population genetic analyses that runs within Microsoft Excel. GenAlEx offers analysis of diploid codominant, haploid and binary genetic loci and DNA sequences. Both frequency-based (F-statistics, heterozygosity, HWE, population assignment, relatedness) and distance-based (AMOVA, PCoA, Mantel tests, multivariate spatial autocorrelation) analyses are provided. New features include calculation of new estimators of population structure: G′ST, G′′ST, Jost’s Dest and F′ST through AMOVA, Shannon Information analysis, linkage disequilibrium analysis for biallelic data and novel heterogeneity tests for spatial autocorrelation analysis. Export to more than 30 other data formats is provided. Teaching tutorials and expanded step-by-step output options are included. The comprehensive guide has been fully revised.
|
| [25] |
|
| [26] |
|
| [27] |
王霞, 王静, 蒋敬虎, 等. 观光木片断化居群的遗传多样性和交配系统[J]. 生物多样性, 2012, 20(6):676-684.
观光木(Tsoongiodendron odorum)是我国特有的濒危植物, 有居群较小、间断分布的特点。为探讨生境片断化对观光木居群的遗传多样性和交配系统的影响, 我们采用8对微卫星引物对采自广东南昆山的观光木片断化居群的61个成株和15个家系共780个种子进行了基因分型, 调查了5个空间隔离的斑块中观光木的两代遗传多样性以及各个层次(居群、斑块及个体)的交配系统参数。结果显示: 片断化生境中观光木成株遗传多样性水平适中(H<sub>E</sub> = 0.522), 种子遗传多样性比成株稍低(H<sub>E</sub> = 0.499), 但没有显著的差异, 近交系数在种子中也没有显著的升高, 暗示生境片断化并没有侵蚀观光木的遗传多样性; 多位点交配系统分析(MLTR)结果表明, 该片断化生境中观光木为高度异交树种(t<sub>m</sub> = 1.000), 只有较少的双亲近交(biparental inbreeding)和相关性交配(correlated mating)事件发生, 但有效花粉供体(effective pollen donor)数目较少(N<sub>ep</sub>为3.7–5.4); 5个斑块间异交率差异不明显, 但小的斑块有效花粉供体相对较多; 另外, 观光木个体之间的异交率存在明显差异, 少数个体存在自交现象。这些结果为濒危物种观光木的长期保护提供了重要的遗传学信息。
|
| [28] |
Inferences about plant mating systems increasingly use highly informative genetic markers, and investigate finer facets of the mating system. Here, four extensions of models for the estimation mating systems are described. (1) Multiallelic probabilities for the mixed selfing-random mating model are given; these are especially suitable for microsatellites; a generalized Kronecker operator is basis of this formula. (2) Multilocus probabilities for the "correlated-matings model" are given; interestingly, comparisons between single- vs multilocus estimates of correlated-paternity can provide a new measure of population substructure. (3) A measure of biparental inbreeding, the "correlation of selfing among loci", is shown to approximate the fraction of selfing due to uniparental (as opposed to biparental) inbreeding; also joint estimation of 1- 2- and 3-locus selfing rates allow separation, under a simple model, of the frequency vs the magnitude of biparental inbreeding. (4) Method-of-moments estimators for individual outcrossing rates are given. Formulae are given for both gymnosperms and angiosperms, and the computer program "MLTR" implements these methods.
|
| [29] |
|
| [30] |
|
| [31] |
徐刚标. 植物群体遗传学[M]. 北京: 科学出版社, 2009:39-68.
|
| [32] |
杨汉波, 张蕊, 周志春. 木荷种子园的遗传多样性和交配系统[J]. 林业科学, 2016, 52(12):66-73.
|
| [33] |
谭小梅, 周志春, 金国庆, 等. 马尾松二代无性系种子园遗传多样性和交配系统分析[J]. 林业科学, 2012, 48(2):69-74.
|
| [34] |
We aimed to investigate inter-year variability in mating system and paternity in an experimental Norway spruce (Picea abies (L.) Karst.) clonal seed orchard that was established with five geographically distinct populations. Using five nuclear microsatellite markers, we analysed 1396 progeny of five mother trees representing each of the populations in three successive mast-years. Selfing varied among mother trees, ranging from 0% to 18.3% with a mean of 13.9% in 1994, 10.1% in 2004, and 7.6% in 2006. Considerable background pollination was observed in each of the three studied mast-years and reached ca. 58%. The paternity assignment conducted showed an uneven male contribution to the seed crop, what was partly related to the number of ramets per paternal clone. All provenances contributed to the seed crop, but with different input, and two provenances dominated. Effective pollen dispersal was significantly determined by distance, with 72.2% of the seed crop resulting from crosses at a distance of up to 15 m. Our study indicated that despite considerable differences in the geographic origin of populations, inter-mating between clones from each population was possible, which generally agrees with the expectations related to the establishment of this seed orchard.
|
| [35] |
|
| [36] |
|
| [37] |
何亚平, 费世民, 徐嘉, 等. 四川麻疯树花序结构和雌雄花动态研究[J]. 四川林业科技, 2008, 29(2):1-8.
|
| [38] |
|
| [39] |
|
| [40] |
周志春, 余能健, 金国庆. 南方红豆杉和三尖杉药用种质选择及高效栽培[M]. 北京: 中国林业出版社, 2009:41-57.
|
中国林业科学研究院亚热带林业实验中心曾平生、姚甲宝、厉月桥、刘素贞和张利利等,浙江省龙泉市林业科学研究院冯建国、徐肇友和肖纪军等,福建省明溪红豆杉产业研究所余能健等在野外取样过程中给予了帮助。
/
| 〈 |
|
〉 |
