风筝果镜像花的雌雄异位变化及传粉生态型的形成

doi:10.17520/biods.2016248

摘要/Abstract

摘要：

亚洲特有植物风筝果(Hiptage benghalensis)镜像花(mirror-image flowers)的雌雄异位变化极大, 柱头与可育花药的空间距离在海南岛与云南西双版纳种群仅有2-4 mm, 而在贵州及云南东南部种群可达10-12 mm。为验证 “镜像花雌雄异位的变化是各个地理种群受到传粉昆虫体型大小选择的结果”假说, 本文开展了传粉生态学与分子生物学研究, 探讨风筝果不同地理种群的雌雄异位变化是否与当地传粉者体型相关, 是否有着遗传基础, 以及是否形成了“传粉生态型”(pollination ecotype)。结果表明, 雌雄异位程度大的贵州种群和云南东南部种群, 其传粉者也是体型较大的木蜂(Xylocopa nasalis)和熊蜂一种(Bombus sp.); 雌雄异位程度小的海南岛种群和云南西双版纳种群的传粉者则是体型较小的大蜜蜂(Apis dorsata)、西方蜜蜂(A. mellifera)。除了雌雄异位的明显分化(F = 53.69, P < 0.01)之外, 花柱长度也在这两类种群之间差异显著(F = 12.5, P < 0.05), 与传粉昆虫身体长度密切相关。通过叶绿体ycf1b、rbcL和细胞核ITS 3个DNA片段的序列分析, 由大型蜂传粉的雌雄异位程度较大的3个种群(贵州和云南东南部种群)遗传关系极近, 与小型蜂传粉种群(雌雄异位较小的海南岛种群和云南西双版纳种群)存在明显的遗传分化。这些结果显示, 风筝果不同地理种群的镜像花雌雄异位程度的变化可能是适应局域不同体型大小的传粉昆虫的选择结果, 而且种群间出现了基因流的隔断, 可能与大型蜂、小型蜂传粉的两种生态型有关。镜像花通过雌雄异位的变化适应不同地域的传粉者而形成传粉生态型, 这种传粉生态型及其传粉隔离机制可能是风筝果属物种形成与维持的一个重要原因。

关键词: 适应进化, 传粉效率, 繁殖隔离, 遗传距离, ycf1b, rbcL, ITS

Abstract

Herkogamy, the spatial separation of sexual organs within flowers, has long been thought to be a floral adaptation of reducing self pollination in hermaphrodites. Herkogamy of mirror-image flowers in the Asian endemic Hiptage benghalensis (Malpighiaceae) varies greatly between populations on Hainan Island (smaller than 4 mm) and Guizhou Province (larger than 10 mm). Such divergence in herkogamy could be adaptive to pollinator body size, which relates to pollen placement and stigma contact position. Recipient selection between local pollinators and plants may facilitate pollinator assembly in isolated populations, even forming pollination ecotypes. Pollinators were investigated in six geographic populations of H. benghalensis to study whether variations in herkogamy correspond to pollinator size. Molecular markers with nuclear ITS 1/4, chloroplast ycf1b and rbcL were also used to detect genetic differentiation between populations with large or small herkogamy. Our data showed small herkogamy in two populations from Hainan Island and one population from Xishuangbanna (southern Yunnan Province) as they were pollinated by small bees including Apis dorsata and Apis mellifera, with an abdomen width varying from 2 to 4 mm. Two populations from Guizhou Province and one population from Southeast Yunnan with larger herkogamy were pollinated by carpenter bees Xylocopa nasalis and bumble bees (Bombus sp.), with an obvious larger body size with a mean abdomen width of 11 mm. The style length (F = 12.5, P < 0.05) was also significantly different between large versus small herkogamous populations. Genetic data based on nuclear (ITS 1/4) and chloroplast (rbcL and ycf1) DNA also supported the differentiation between small and large herkogamous populations. These results indicated associations between flower and pollinator size, suggesting pollination ecotypes in H. benghalensis. This study indicated that the pollination ecotype in mirror-image flowers was associated with variations in herkogamy.

Key words: adaptive evolution, pollination efficiency, reproductive isolation, genetic distance, ycf1b, rbcL, ITS

钱贞娜, 孟千万, 任明迅 (2016) 风筝果镜像花的雌雄异位变化及传粉生态型的形成. 生物多样性, 24, 1364-1372. DOI: 10.17520/biods.2016248.

Zhenna Qian, Qianwan Meng, Mingxun Ren (2016) Pollination ecotypes and herkogamy variation of Hiptage benghalensis (Malpighiaceae) with mirror-image flowers. Biodiversity Science, 24, 1364-1372. DOI: 10.17520/biods.2016248.

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https://www.biodiversity-science.net/CN/Y2016/V24/I12/1364

图/表 6

图1 风筝果的镜像花及花部关键性状的测量。R: 右偏花柱型; L: 左偏花柱型; HK: 雌雄异位; SL: 花柱长; AS: 花药分离。

Fig. 1 Mirror-image flowers and measurements of key floral traits in Hiptage benghalensis. R, Right-styled flower; L, Left-styled flower; HK, Herkogamy; SL, Style length; AS, Anther separation.

表1 风筝果6个种群的地理位置与花柱右偏、左偏两种花型的比率

Table 1 Geographic locations and ratio of right- and left-styled flowers of Hiptage benghalensis populations

地点 Location	居群 Population	经纬度 Latitude/longitude	海拔 Altitude (m)	种群两种花型比率 Right/Left-styled flowers	χ ²	P
贵州 Guizhou	GZ-LK	25°05′24″ N, 106°12′59″ E	466	1:1 (21/21)	0	1
贵州 Guizhou	GZ-ZX	24°58′29″ N, 106°08′09″ E	442	1:1 (18/18)	0	1
云南 Yunnan	YN-YJ	23°20′17″ N, 102°11′52″ E	1,758	1:1.18 (11/13)	0.75	0.68
云南 Yunnan	YN-BN	21°52′16″ N, 101°19′27″ E	570	1:1 (32/32)	0	1
海南 Hainan	HN-BW	19°06′18″ N, 109°06′18″ E	223	1:1.50 (36/41)	1.2	0.27
海南 Hainan	HN-DL	18°43′19″ N, 109°52′24″ E	332	1:1.33 (28/39)	0.28	0.59

表2 确定风筝果地理种群遗传关系的DNA片段及其引物

Table 2 DNA fragments and the primers used for genetic studies of Hiptage benghalensis populations

DNA片段	引物序列 Sequence	片段大小 Fragment size	参考文献 Reference
核基因 ITS 1/4	ITS1: TCCGTAGGTGAACCTGCG ITS4: TCCTCCGCTTATTGATATGC	651 bp	White et al, 1990
叶绿体 rbcL	1F: ATGTCACCACAAACAGAAAC 724R: TCGCATGTACCTGCAGTAGC	715 bp	Davis & Anderson, 2010
叶绿体 ycf1b	F: TCTCGACGAAAATCAGATTGTTGTGAAT R: ATACATGTCAAAGTGATGGAAAA	926 bp	Dong et al, 2015

图2 不同地理种群的风筝果镜像花的雌雄异位(A)、花柱长(B)、花药分离(C)情况

Fig. 2 Boxplot of variations in herkogamy (A), style length (B) and anther separation (C) of mirror-image flowers among Hiptage benghalensis populations

图3 风筝果不同地理种群的传粉者。(A)竹木蜂(贵州GZ-LK种群); (B)竹木蜂(贵州GZ-ZX种群); (C)熊峰(云南YN-YJ种群); (D)花粉粘附在竹木蜂胸部与腹部(红色圆圈处); (E)西方蜜蜂(云南YN-BN种群); (F)大蜜蜂(海南HN-BW种群)。

Fig. 3 Pollinators in different geographic populations of Hiptage benghalensis. (A) and (B), Xylocopa nasalis visiting GZ-LK and GZ-ZX populations in Guizhou Province; (C) Bombus sp. visiting YN-YJ Population in Yunnan Province; (D) Pollen grains (red circles) on the thorax and abdomen of a carpenter bee; (E) Apis mellifera in YN-BN Population in Yunnan Province; (F) Apis dorsata in HN-BW Population on Hainan Island.

图4 风筝果的传粉生态型。种群遗传关系树使用邻接法(分支上的数字代表支持率), 数据来源于1个核基因片段(ITS 1/4)及2个叶绿体基因片段(rbcL和ycf1b)。柱状图为雌雄异位程度与传粉昆虫腹部宽度的平均值, 纵坐标单位为mm。

Fig. 4 Pollination ecotypes of Hiptage benghalensis. Neighbor-joining phylogenetic tree was drawn based on ITS1/4 and chloroplast (rbcLand ycf1b) DNA sequences. The histograms on the map refer to the mean values of herkogamy, and the unit of ordinate is millimeter (mm). ■ Herkogamy (righ-styled flower); □ Pollinator abdomen width; Herkogamy (left-styled flower).

参考文献 42

[1]	Anderson B, Alexandersson R, Johnson SD (2009) Evolution and coexistence of pollination ecotypes in an African Gladiolus (Iridaceae). Evolution, 64, 960-972.
[2]	Barrett SCH, Jesson LK, Baker AM (2000) The evolution and function of stylar polymorphisms in ?owering plants. Annals of Botany, 85, 253-265.
[3]	Cao LF, Hu FL (2012) Biological characters of Apis dorsata from China. Journal of Bee, 32, 1-2.
[4]	Chen SK (1977) Flora Reipublicae Popularis Sinicae, Tomus 43, p.119. Science Press, Beijing.
	(in Chinese) [陈书坤 (1977) 中国植物志, 43卷, 119页. 科学出版社, 北京.]
[5]	Chen S, Funston AM (2008) Malpighiaceae. In: Flora of China (eds Wu ZY, Raven PH, Hong DY), pp. 132-138. Science Press, Beijing & Missouri Botanical Garden Press, St. Louis.
[6]	Davis CC, Anderson WR (2010) A complete generic phylogeny of Malpighiaceae inferred from nucleotide sequence data and morphology. American Journal of Botany, 97, 2031-2048.
[7]	Doley JJ, Doley JL (1987) A rapid DNA isolation procedure for small quantities of fresh leaf tissue. Phytochemical Bulletin, 19, 11-15.
[8]	Dong WP, Chao X, Li CH, Sun JH, Zuo YJ, Shi S, Cheng T, Guo JJ, Zhou SL (2015) ycf1, the most promising plastid DNA barcode of land plants. Scientific Reports, 5, 8348.
[9]	Duffy KJ, Scopece G, Cozzolino S, Fay MF, Smith RJ, Stout JC (2009) Ecology and genetic diversity of the dense- flowered orchid, Neotinea maculata, at the centre and edge of its range. Annals of Botany, 104, 507-516.
[10]	Dulberger R (1981) The floral biology of Cassia didymobotrya and C. auriculata (Caesalpiniaceae). American Journal of Botany, 68, 1350-1360.
[11]	Excoffier L, Smouse PE, Quattro JM (1992) Analysis of molecular variance inferred from metric distance among DNA haplotypes: application to human mitochondrial DNA restriction data. Genetics, 131, 479-491.
[12]	Fortuna MA, García C, Guimarães PR Jr, Bascompte J (2008) Spatial mating networks in insect-pollinatd plants. Ecology Letters, 11, 490-498.
[13]	Gao JY, Ren PY, Yang ZH, Li QJ (2006) The pollination ecology of Paraboea rufescens (Gesneriaceae), a buzz- pollinated tropical herb with mirror-image flowers. Annals of Botany, 97, 371-376.
[14]	Grant V, Grant KA (1965) Flower Pollination in the Phlox Family. Columbia University Press, New York.
[15]	Huang SQ, Shi XQ (2013) Floral isolation in Pedicularis: how do congeners with shared pollinators minimize reproductive interference? New Phytologist, 199, 858-865.
[16]	Jesson LK, Barrett SCH (2002) Solving the puzzle of mirror-image flowers. Nature, 417, 707.
[17]	Jesson LK, Barrett SCH (2003) The comparative biology of mirror-image flowers. International Journal of Plant Sciences, 164, 237-249.
[18]	Johnson SD (1997) Pollination ecotypes of Satyrium hallackii (Orchidaceae) in South Africa. Botanical Journal of the Linnean Society, 123, 225-235.
[19]	Johnson SD, Steiner KE (1997) Long-tongued fly pollination and evolution of floral spur length in the Disa draconis Complex (Orchidaceae). Evolution, 51, 45-53.
[20]	Johnson SD, Steiner KE (2000) Generalization vs. specialization in plant pollination systems. Trends in Ecology & Evolution, 15, 140-143.
[21]	Johnson SD, Steiner KE (2003) Specialized pollination systems in southern Africa. South African Journal of Science, 99, 345-348.
[22]	Lin Y, Tan DY (2007) Enantiostyly in angiosperms and its evolutionary significance. Acta Phytotaxonomica Sinica, 45, 901-916.(in Chinese with English abstract)
	[林玉, 谭敦炎(2007) 被子植物镜像花柱及其进化意义. 植物分类学报,45, 901-916.]
[23]	Parisod C, Joost S (2010) Divergent selection in trailing-versus leading-edge populations of Biscutella laevigata. Annals of Botany, 105, 655-660.
[24]	Qian ZN, Ren MX (2016) Floral evolution and pollination shifts of the “Malpighiaceae route” taxa, a classical model for biogeographical study. Biodiversity Science, 24, 95-101.(in Chinese with English abstract)
	[钱贞娜, 任明迅 (2016) “金虎尾路线”植物的花进化与传粉转变. 生物多样性,24, 95-101.]
[25]	Qing Z, Su R, Dong K, Shao Y (2014) Research progress on nectar compositions and their ecological functions. Chinese Journal of Ecology, 33, 825-836.(in Chinese with English abstract)
	[卿卓, 苏睿, 董坤, 绍禹 (2014) 花蜜化学成分及其生态功能研究进展. 生态学杂志,33, 825-836.]
[26]	Ren MX (2015) The upper reaches of the largest river in Southern China as an ‘evolutionary front’ of tropical plants: evidences from Asia-endemic genus Hiptage (Malpighiaceae). Collectanea Botanica, 34, e003.
[27]	Ren MX, Zhang DY (2004) Herkogamy. In: Plant Life-History Evolution and Reproductive Ecology (ed. Zhang DY), pp. 303-320. Science Press, Beijing.(in Chinese)
	[任明迅, 张大勇 (2004) 雌雄异位. 见: 植物生活史进化与繁殖生态学 (张大勇主编), 303-320页. 科学出版社, 北京.]
[28]	Ren MX, Zhong YF, Song XQ (2013) Mirror-image flowers without buzz pollination in the Asia-endemic Hiptage benghalensis (Malpighiaceae). Botanical Journal of the Linnean Society, 173, 764-774.
[29]	Robertson JL, Wyatt R (1990) Evidence for pollination ecotypes in the yellow fringed orchid, Platanthera ciliaris. Evolution, 44, 121-133.
[30]	Sirirugsa P (1991) Malpighiaceae. In: Flora of Thailand (eds Smitinand T, Larsen K), pp. 272-299. The Forest Herbarium, Royal Forest Department, Bangkok.
[31]	Stebbins GL (1970) Adaptive radiation of reproductive characteristics in angiosperms. I. Pollination mechanisms. Annual Review of Ecology and Systematics, 1, 307-326.
[32]	Tamura K, Stecher G, Peterson D, Filipski A, Kumar S (2013) MEGA6: Molecular Evolutionary Genetics Analysis, version 6.0. Molecular Biology and Evolution, 16, 1-5.
[33]	Tang LL, Huang SQ (2007) Evidence for reductions in floral attractants with increased selfing rates in two heterandrous species. New Phytologist, 175, 588-595.
[34]	Thomas SG, Rehel SM, Varghese A, Davidar P, Potts SG (2009) Social bees and food plant associations in the Nilgiri Biosphere Reserve, India. Tropical Ecology, 50, 79-88.
[35]	Todd JE (1882) On the flowers of Solanum rostratum and Cassia chamaecrista. The American Naturalist, 16, 281-287.
[36]	Van der Niet T, Pirie MD, Shuttleworth A, Johnson SD, Midgley JJ (2014) Do pollinator distributions underlie the evolution of pollination ecotypes in the Cape shrub Erica plukenetii? Annals of Botany, 113, 301-315.
[37]	Vaidya G, Lohman DJ, Meier R (2011) Sequence Matrix, concatenation software for the fast assembly of multi-gene datasets with character set and codon information. Cladistics, 27, 171-180.
[38]	Vitelli JS, Madigan BA, Van Haaren PE, Setter S, Logan P (2009) Control of the invasive liana, Hiptage benghalensis. Weed Biology and Management, 9, 54-62.
[39]	Webb CJ, Lloyd DG (1986) The avoidance of interference between the presentation of pollen and stigmas in angiosperms. II. Herkogamy. New Zealand Journal of Botany, 24, 163-178.
[40]	White TJ, Bruns T, Lee S, Taylor J (1990) Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: PCR Protocols: A Guide to Methods and Applications (eds Innis MA, Gelfand DH, Sninsky JJ, White TJ ), pp. 315-322. Academic Press, New York.
[41]	Whittall JB, Hodges SA (2007) Pollinator shifts drive increasingly long nectar spurs in columbine flowers. Nature, 447, 706-709.
[42]	Wu YR (2000) Fauna Sinica. Insecta, Vol. 20. Hymenoptera: Melittidae, Apidae, pp. 21-30, 123-130. Science Press, Beijing.(in Chinese)
	[吴燕如 (2000) 中国动物志: 昆虫纲, (第二十卷): 膜翅目, 准蜂科, 蜜蜂科), 21-30, 123-130页. 科学出版社, 北京.]