峨眉拟单性木兰的开花生物学特性与繁育系统
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摘要
为阐明峨眉拟单性木兰(Parakmeria omeiensis)在自然条件结实率低的原因和确定最佳人工授粉时期,该文通过观察峨眉拟单性木兰的开花动态,采用杂交指数估算、花粉胚珠比、花粉活力及柱头活性检测、人工授粉试验等方法对其繁育系统进行了研究。结果表明:(1)植物园保育的峨眉拟单性木兰花期在4月底到5月中下旬,持续17～23 d,雄株始花期比雌株早3～4 d,但两者花期可遇。(2)两性花经检测雄蕊败育,实为功能上的雌性,部分雄株个体的雄花上残留1～2个心皮,其性别分化是通过雌、雄蕊选择性败育形成的,为隐性雌雄异株(cryptic dioecy)。(3)雄花、两性花开放经历佛焰苞开裂、花被片开裂、展开、闭合、二次开放、凋落6个阶段,历时4 d。(4)雄花初次展开时花粉活力最高,达92.8%,开花2 d后活力显著下降;两性花柱头在花被片展开期可授性最强,盛开后柱头部分可授。(5)杂交指数为5,P/O比为2.14×10~4。(6)套袋试验表明,峨眉拟单性木兰不能进行自花传粉,人工异花授粉的结实率和出种数显著高于自然授粉,且不存在无融合生殖。这说明峨眉拟单性木兰繁育系统为专性异交,传粉过程需要传粉媒介,自然条件下结实率低,主要是受传粉昆虫和柱头可授期短的限制。
In order to explain the reasons for the low seed-setting rate of Parakmeria omeiensis in natural condition and determine the optimum pollinating time. The floral character were studied through field observation in Mount Emei,the type of breeding system was estimated by out-crossing index( OCI),the pollen-ovule ratio( P/O),pollen viability and the stigma receptivity,and the artifical pollination experiments were carried out. The results were as follows:( 1) The florescence of P. omeiensis was from late April to mid-late May. Male plants bloomed 3-4 d earlier than female plants,and their florescence were overlapped.( 2) Bisexual flowers were actually female in reproductive function,1-2 carpels remained on the male flower of some male plants. The selective abortion of either pistil or stamens led to sex differentiation. So P. omeiensis belongs to cryptic dioecy.( 3) The flowering process followed six stages from spathe dehiscence,tepal dehiscence,spreading,closing,the second spreading to flowers withering,which took 4 d.( 4) The viability of pollen in male flowers reached the highest( 92.8%) during the first spreading,and then descended greatly after 2 d. The stigmas of bisexual flowers were strong receptivity when all tepals were spreading,while some stigmas were receptive after bloo-ming.( 5) The outcrossing index( OCI) was five and pollen/ovule was 2.14×10~4,which indicates that P. omeiensis should be classified as an allogamous plant.( 6) The artificial pollination revealed the self-pollination phenomenon did not exist and had no apomixis phenomenon. The fruit-setting rate and seed-setting rate were significantly higher than that of natural pollination. In conclusion,the breeding system of P. omeiensis was obligate cross-pollination which requires pollinators,and its fruit-setting rate was limited by pollinators and the short stigma receptivity under natural conditions.
In order to explain the reasons for the low seed-setting rate of Parakmeria omeiensis in natural condition and determine the optimum pollinating time. The floral character were studied through field observation in Mount Emei,the type of breeding system was estimated by out-crossing index( OCI),the pollen-ovule ratio( P/O),pollen viability and the stigma receptivity,and the artifical pollination experiments were carried out. The results were as follows:( 1) The florescence of P. omeiensis was from late April to mid-late May. Male plants bloomed 3-4 d earlier than female plants,and their florescence were overlapped.( 2) Bisexual flowers were actually female in reproductive function,1-2 carpels remained on the male flower of some male plants. The selective abortion of either pistil or stamens led to sex differentiation. So P. omeiensis belongs to cryptic dioecy.( 3) The flowering process followed six stages from spathe dehiscence,tepal dehiscence,spreading,closing,the second spreading to flowers withering,which took 4 d.( 4) The viability of pollen in male flowers reached the highest( 92.8%) during the first spreading,and then descended greatly after 2 d. The stigmas of bisexual flowers were strong receptivity when all tepals were spreading,while some stigmas were receptive after bloo-ming.( 5) The outcrossing index( OCI) was five and pollen/ovule was 2.14×10~4,which indicates that P. omeiensis should be classified as an allogamous plant.( 6) The artificial pollination revealed the self-pollination phenomenon did not exist and had no apomixis phenomenon. The fruit-setting rate and seed-setting rate were significantly higher than that of natural pollination. In conclusion,the breeding system of P. omeiensis was obligate cross-pollination which requires pollinators,and its fruit-setting rate was limited by pollinators and the short stigma receptivity under natural conditions.
引文
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CHAI YX,CAI MY,JIN XL,et al.,2017.Pollination biology of Michelia crassipes[J].Guihaia,37(10):1322-1329.[柴弋霞,蔡梦颖,金晓玲,等,2017.紫花含笑传粉生物学初探[J].广西植物,37(10):1322-1329.]
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CHEN Y,MA MD,2008.Axillary bud and callus induction of stem segment endangered plant of Parakmeria omeiensis[J].Ann For Sci,33(1):10-12.[陈英,马明东,2008.濒危植物峨眉拟单性木兰茎段腋芽及愈伤组织诱导[J].林业科技,33(1):10-12.]
CRUDEN RW,1977.Pollen-ovule rations:A conservative indicator of breeding systems in flowering plants[J].Evolution,31:32-46.
DAFNI A,1992.Pollination biology-practical approach[M].New York:Oxford University Press:1-57.
FANG ZQ,LI CH,YU DP,et al.,2017.Report on biodiversity monitoring and assessment of Mount Emei[J][方志强,李策宏,余道平,等,2017.峨眉山生物多样性监测与评估报告].
FU YB,CHEN SY,WU T,2010.Comparison of floral traits and breeding system of endangered plant Manglietia grandis and non-endangered plant Manglietia hookeri[J].J NE Fort Univ,38(4):6-10.[付玉嫔,陈少瑜,吴涛,2010.濒危植物大果木莲与中缅木莲的花部特征及繁育系统比较[J].东北林业大学学报,38(4):6-10.]
HU XS,ZHENG WJ,1951.A new genus-Parakmeria Hu et Cheng of Magnoliaceae in the Southwest of China[J].Acta Phytotax Sin,1(1):1-3.[胡先骕,郑万均,1951.拟克抹丽木,中国西南部木兰科一新属[J].植物分类学报,1(1):1-3.]
LAN JY,PAN CL,QIN WG,et al.,2007.Pollination ecology of rare and endangered species Kmeria septentrionlis[J].Guihaia,27(5):736-740.[赖家业,潘春柳,覃文更,等,2007.珍濒危植物单性木兰传粉生态学研究[J].广西植物,27(5):736-740.]
LIU KL,WANG YL,ZHANG SZ,2013.Flowering biology and pollen germination of Magnolia championii[J].Subtrop Plant Sci,42(4):293-296.[刘坤良,王亚玲,张寿洲,2013.香港木兰开花生物学研究[J].亚热带植物科学,42(4):293-296.]
LIU YH,XIA NH,YANG HQ,1995.The origin,evolution and phytogeography of magnoliaceae[J].J Trop Subtrop Bot,3(4):1-12.[刘玉壶,夏念和,杨惠秋,1995.木兰科的起源、进化和地理分布[J].热带亚热带植物学报,3(4):1-12.]
MENG X,WANG RH,XIE L,et al.,2011.Flowering dynamics and dichogamous mechnism in Magnolia grandiflora[J].J Beijing For Univ,33(4):63-69.[孟希,王若涵,谢磊,等,2011.广玉兰开花动态与雌雄异熟机制的研究[J].北京林业大学学报,33(4):31-33.]
PAN LQ,HAO J,XU JM,et al.,2018.Flowering dynamics and dichogamy characteristics of Manglietia glauca for twotime flower opening and closure[J].J Zhejiang A&FUniv,35(1):96-103.[潘丽琴,郝建,徐建民,等,2018.灰木莲二次开合开花动态与雌雄异熟特征[J].浙江农林大学学报,35(1):96-103.]
QIAN YF,LI YX,CHEN LY,et al.,2015.Pollination biology of Michelia maudiae[J].Guihaia,35(1):35-41.[钱一凡,黎云祥,陈兰英,等,2015.深山含笑传粉生物学研究[J].广西植物,35(1):35-41.]
SUN Y,2015.Study on reproductive biology of the rare andprotected plant-Magnolia dawsoniana[D].Chengdu:Sichuan Agricultural University:1-55.[孙燕,2015.珍稀保护植物光叶木兰生殖生物学研究[D].成都:四川农业大学:1-55.]
WANG RH,JIA H,ZHANG ZX,et al.,2010.Flowering and pollination patterns of Magnolia denudata with emphasis on anatomical changes in ovule and seed development[J].Flora,205(4):259-265.
WANG YB,LIANG HW,MO NB,et al.,2011.Flower phenology and breeding system of rare and endangered Dayaoshania cotinifolia[J].Acta Bot Sin,31(5):861-867.[王玉兵,梁宏伟,莫耐波,等,2011.珍稀濒危植物瑶山苣苔开花生物学及繁育系统研究[J].西北植物学报,31(5):861-867.]
XU FX,2002.Study on pollen morphology of Parakmeria lotungensis[J].Guihaia,22(2):157-159.[徐凤霞,2002.乐东拟单性木兰花粉形态观察[J].广西植物,22(2):157-159.]
XU JH,LI DX,LI YY,2002.Biological and ecological characteristics of Parakmeria yunnanensis and its role in urban afforesting and greening[J].West For Sci Technol,(2):31-33.[徐加汉,李达孝,李玉媛,2002,云南拟单性木兰生物生态学特性及其城市绿化的作用[J].西部林业科技,(2):31-33.]
YANG XL,2013.Studies on conservation biology of endangered species Manglietia pachyphylla[D].Beijing:University of Chinese Academy of Sciences:1-74.[杨晓丽,2013.濒危植物厚叶木莲的保护生物学研究[D].北京:中国科学院大学:1-74.]
YANG X,YANG ZL,WANG J,et al.,2012.Flora syndrome and breeding system of endangered species Magnolia officinalis subsp.biloba[J].Chin J Ecol,31(3):551-556.[杨旭,杨志玲,王洁,等,2012.濒危植物凹叶厚朴的花部综合特征和繁育系统[J].生态学杂志,31(3):551-556.]
YU DP,LI CH,2017.Resuming Parakmeria omeiensis,an critically endangered species endemic to Sichuan,China[J].Greentianfu,(9):26-27.[余道平,李策宏,2017.极度濒危植物峨眉拟单性木兰的拯救保护[J].绿色天府,(9):26-27.]
YU DP,LI CH,DING J,et al.,2011.Preliminary report on character of seed and seed culture in virto of Parakmeria omeiensis[J].Resour Dev Mark,27(3):197-198.[余道平,李策宏,丁健,等,2011.峨眉拟单性木兰种子特性及离体培养初报[J].资源开发与市场,27(3):197-198.]
YU SH,2017.The preliminary study on characteristics of reproductive biology in Magnolia sieboldii in Shenyang[D].Shenyang:Sichuan Agricultural University:1-41.[于思桦,2017.沈阳地区天女木兰生殖生物学特性的初步研究[D].沈阳:沈阳农业大学:1-41.]
ZHANG P,LIU RY,LIANG KH,1993.A preliminary study on phytocoenological characteristics of Parakmeria omeiensis community[J].Guihaia,13(1):61-69.[庄平,刘仁英,梁开和,1993.峨眉拟单性木兰群落特征的初步研究[J].广西植物,13(1):61-69.]
CHAI YX,CAI MY,JIN XL,et al.,2017.Pollination biology of Michelia crassipes[J].Guihaia,37(10):1322-1329.[柴弋霞,蔡梦颖,金晓玲,等,2017.紫花含笑传粉生物学初探[J].广西植物,37(10):1322-1329.]
CHEN HF,2006.Study on conservation biology of Parakmeria lotungensis[D].Guangzhou:South China Botanical Garden,CAS:1-147.[陈红锋,2006.濒危植物乐东拟单性木兰的保护生物学研究[D].广州:中国科学院华南植物园:1-147.]
CHEN Y,MA MD,2008.Axillary bud and callus induction of stem segment endangered plant of Parakmeria omeiensis[J].Ann For Sci,33(1):10-12.[陈英,马明东,2008.濒危植物峨眉拟单性木兰茎段腋芽及愈伤组织诱导[J].林业科技,33(1):10-12.]
CRUDEN RW,1977.Pollen-ovule rations:A conservative indicator of breeding systems in flowering plants[J].Evolution,31:32-46.
DAFNI A,1992.Pollination biology-practical approach[M].New York:Oxford University Press:1-57.
FANG ZQ,LI CH,YU DP,et al.,2017.Report on biodiversity monitoring and assessment of Mount Emei[J][方志强,李策宏,余道平,等,2017.峨眉山生物多样性监测与评估报告].
FU YB,CHEN SY,WU T,2010.Comparison of floral traits and breeding system of endangered plant Manglietia grandis and non-endangered plant Manglietia hookeri[J].J NE Fort Univ,38(4):6-10.[付玉嫔,陈少瑜,吴涛,2010.濒危植物大果木莲与中缅木莲的花部特征及繁育系统比较[J].东北林业大学学报,38(4):6-10.]
HU XS,ZHENG WJ,1951.A new genus-Parakmeria Hu et Cheng of Magnoliaceae in the Southwest of China[J].Acta Phytotax Sin,1(1):1-3.[胡先骕,郑万均,1951.拟克抹丽木,中国西南部木兰科一新属[J].植物分类学报,1(1):1-3.]
LAN JY,PAN CL,QIN WG,et al.,2007.Pollination ecology of rare and endangered species Kmeria septentrionlis[J].Guihaia,27(5):736-740.[赖家业,潘春柳,覃文更,等,2007.珍濒危植物单性木兰传粉生态学研究[J].广西植物,27(5):736-740.]
LIU KL,WANG YL,ZHANG SZ,2013.Flowering biology and pollen germination of Magnolia championii[J].Subtrop Plant Sci,42(4):293-296.[刘坤良,王亚玲,张寿洲,2013.香港木兰开花生物学研究[J].亚热带植物科学,42(4):293-296.]
LIU YH,XIA NH,YANG HQ,1995.The origin,evolution and phytogeography of magnoliaceae[J].J Trop Subtrop Bot,3(4):1-12.[刘玉壶,夏念和,杨惠秋,1995.木兰科的起源、进化和地理分布[J].热带亚热带植物学报,3(4):1-12.]
MENG X,WANG RH,XIE L,et al.,2011.Flowering dynamics and dichogamous mechnism in Magnolia grandiflora[J].J Beijing For Univ,33(4):63-69.[孟希,王若涵,谢磊,等,2011.广玉兰开花动态与雌雄异熟机制的研究[J].北京林业大学学报,33(4):31-33.]
PAN LQ,HAO J,XU JM,et al.,2018.Flowering dynamics and dichogamy characteristics of Manglietia glauca for twotime flower opening and closure[J].J Zhejiang A&FUniv,35(1):96-103.[潘丽琴,郝建,徐建民,等,2018.灰木莲二次开合开花动态与雌雄异熟特征[J].浙江农林大学学报,35(1):96-103.]
QIAN YF,LI YX,CHEN LY,et al.,2015.Pollination biology of Michelia maudiae[J].Guihaia,35(1):35-41.[钱一凡,黎云祥,陈兰英,等,2015.深山含笑传粉生物学研究[J].广西植物,35(1):35-41.]
SUN Y,2015.Study on reproductive biology of the rare andprotected plant-Magnolia dawsoniana[D].Chengdu:Sichuan Agricultural University:1-55.[孙燕,2015.珍稀保护植物光叶木兰生殖生物学研究[D].成都:四川农业大学:1-55.]
WANG RH,JIA H,ZHANG ZX,et al.,2010.Flowering and pollination patterns of Magnolia denudata with emphasis on anatomical changes in ovule and seed development[J].Flora,205(4):259-265.
WANG YB,LIANG HW,MO NB,et al.,2011.Flower phenology and breeding system of rare and endangered Dayaoshania cotinifolia[J].Acta Bot Sin,31(5):861-867.[王玉兵,梁宏伟,莫耐波,等,2011.珍稀濒危植物瑶山苣苔开花生物学及繁育系统研究[J].西北植物学报,31(5):861-867.]
XU FX,2002.Study on pollen morphology of Parakmeria lotungensis[J].Guihaia,22(2):157-159.[徐凤霞,2002.乐东拟单性木兰花粉形态观察[J].广西植物,22(2):157-159.]
XU JH,LI DX,LI YY,2002.Biological and ecological characteristics of Parakmeria yunnanensis and its role in urban afforesting and greening[J].West For Sci Technol,(2):31-33.[徐加汉,李达孝,李玉媛,2002,云南拟单性木兰生物生态学特性及其城市绿化的作用[J].西部林业科技,(2):31-33.]
YANG XL,2013.Studies on conservation biology of endangered species Manglietia pachyphylla[D].Beijing:University of Chinese Academy of Sciences:1-74.[杨晓丽,2013.濒危植物厚叶木莲的保护生物学研究[D].北京:中国科学院大学:1-74.]
YANG X,YANG ZL,WANG J,et al.,2012.Flora syndrome and breeding system of endangered species Magnolia officinalis subsp.biloba[J].Chin J Ecol,31(3):551-556.[杨旭,杨志玲,王洁,等,2012.濒危植物凹叶厚朴的花部综合特征和繁育系统[J].生态学杂志,31(3):551-556.]
YU DP,LI CH,2017.Resuming Parakmeria omeiensis,an critically endangered species endemic to Sichuan,China[J].Greentianfu,(9):26-27.[余道平,李策宏,2017.极度濒危植物峨眉拟单性木兰的拯救保护[J].绿色天府,(9):26-27.]
YU DP,LI CH,DING J,et al.,2011.Preliminary report on character of seed and seed culture in virto of Parakmeria omeiensis[J].Resour Dev Mark,27(3):197-198.[余道平,李策宏,丁健,等,2011.峨眉拟单性木兰种子特性及离体培养初报[J].资源开发与市场,27(3):197-198.]
YU SH,2017.The preliminary study on characteristics of reproductive biology in Magnolia sieboldii in Shenyang[D].Shenyang:Sichuan Agricultural University:1-41.[于思桦,2017.沈阳地区天女木兰生殖生物学特性的初步研究[D].沈阳:沈阳农业大学:1-41.]
ZHANG P,LIU RY,LIANG KH,1993.A preliminary study on phytocoenological characteristics of Parakmeria omeiensis community[J].Guihaia,13(1):61-69.[庄平,刘仁英,梁开和,1993.峨眉拟单性木兰群落特征的初步研究[J].广西植物,13(1):61-69.]