Akebia The Coqui Ministry Groups Of Flowers And Leaves, Morphological And Phylogenetic Study

It is widely accepted that Lardizabalaceae is the basal family in Ranunculales which is the basal eudicots.Lardizabalaceae consists of nine genera including Sargentodoxa and seven of them occurr in China.Sargentodoxa,Decaisnea and Sinofranchetia show many primary characters in anatomy, structure,and other aspects,the three genera occupy the primary systematic position in Lardizabalaceae,and they are monotypic genus endemic to China.The ontogeny character of organs includes floral,ovule and leaf morphogenesis and development,the data of ontogeny is the key morphological character to the phylogeny of Lardizabalaceae,and it can supply some fundamental information to organ identity genes.Organ morphogenesis and development of Sargentodoxa,Decaisnea,Sinofranchetia,Akebia and Holboellia in Lardizabalaceae are observed in this paper,the results are as follows:1)Floral morphogenesis in LardizabalaceaeThe functionally unisexual flowers have a bisexual morphogenesis in the early developmental stages;the floral organs arise spirally(or whorled) and whorled arranged later in mature flower.In Sargentodoxa,â…°.the male,female and bisexual flower exist together;â…±.petal retarded;â…². carpels and androecia morphogenesis and development exhibit different pattern in female,bisexual and male flowers in later developmental stages,in the female flower,the floral primordia apex enlarged obviously and more than 90 carpels initiated,the floral apex is occupied totally,the first six carpel appeared as whorled and the numerous carpels occurred irregular later;on the other hand,in the male flower,the floral primordia apex does not enlarged and about 10 or none sterile carpels appeared unordered;the carpel initiation in the bisexual flower is as the same as it in the female flower,the number of the carpels is fewer than it in the female one;â…³.ascidiate carpel with short stalks,the mature carpels have decurrent and oblique stigmas;â…´.the perianth and staminodes number is variable in the female flowers;â…µ.the floral morphgenesis in uppermost flower is different from others.In Decaisnea,â…°.three stamens in the first whorl retarded;â…±.conduplicate carpels with headed stigma;â…².the remained floral apex exist after carpels formed;the staminodes in the female flowers are petaloid.In Sinofranchetia,â…°.petals and androecia are not come from the "common primordium",the petal primordium and the androecium primordium are different in shape,postion and time when they initiate;â…±.petals retarded;â…².three stamens of the first whorl retarded;â…³.conduplicate carpels without style,stigma formed in the upper parts of the carpel and approximately headed;â…´.the staminodes are smaller than the stamen in the male flower;â…µ.the remained floral apex exists after carpels formed.In Akebia,two whorls of sepals occured,and the inner whorl degenerated later;â…±.conduplicate carpels is initiated spirally,stigma formed in the upper parts of the carpel and approximately headed;â…².the staminodes are smaller than the stamen in the male flower.In Holboellia,the petal are differ from the androecium in primordium shape,initiation postion and time;â…±.petals retarded;â…².conduplicate carpels occurred successively with short style,stigma headed.2)Ovules morphogenesis of LardizabalaceaeMature ovules are anatropous,campylotropous to hemianatropous,bitegmic integument.The young ovule is hemisphere;the inner integument is arised annularly in the middle part of the ovule and developed into cup-shaped;the outer integuments formed with semi-annularly shape in Sargentodoxa,Decaisnea,Sinofranchetia,Akebia and Holboellia fargesii Reaub.,in which the outer integument is not formed in the ventral side of the funicle,or the outer integuments arised annularly in Holboellia grandiflora Reaub.and Holboellia latifolia Wall.;the outer integument developed into hood-shaped in the most genera,while Sargentodoxa has a copular-shaped outer integument;the micropyles is endostomic and formed late(the nucellus is not wrapped with integuments obviously in blooming);the raphe-shaped appendages arise in Sinofranchetia.3)Leaf ontogeny of LardizabalaceaeLardizabalaceae have compound leaf,pinnate in Decaisnea,ternate in Sinofranchetia and Sargentodoxa,palmate or trifoliolate in Akebia and Holboellia,rarely simple leaf(in Sargentodoxa, the leaf can be observed varies from ternate leaves to the simple leaf).The compound leaves formed in the leaf bud(or mix bud) with a equal interval gap between two leaf primordia,such as in Decaisnea,Sinofranchetia,Akebia,Holboellia and Stauntonia.The first fractionation of leaf primordium is ternate,and three equal parts formed in the early stage.Three developmental types formed as a result of ternation in compound leaves,ternate, ternate-acropetal and ternate-basipetal,â…°.ternate-acropetal growth in the pinnately compound leaf differentiation in Decaisnea,if the middle part of ternation,which develops further,a pinnate leaf would result,6 to 11 pairs of leaflets initiated from the basal to the upper in middle part,and the tip leaflet formed by the remain part of leaf primordia,the leaflet tissue differentiation is in the same direction in the following development;â…±.ternate-basipetal growth accompany with the palmate compound leaf in Holboellia,the tip leaflet formed by the middle part of ternation,and with short basipetal growth,1 to 4 pairs of leaflets initiated successively from upper to the basal below the middle part;â…².if the ternation does not develop further,three part formed the tip leaflet and two lateral leaflets,and results into ternate or trifoliolate compound leaf in Sinofranchetia,Akebia (Akebia trifoliata(Thunb.) Koidz.)and Sargentodoxa.4)Phylogeny analysisThe results based on 105 morphological characters show that Lardizabalaceae is monophyletic with a bootstrap support of 80%.Within Lardizabalaceae,Sargentodoxa is the most archaic genus which is sister to other genera of Lardizabalaceae with a bootstrap support of 80%,Decaisnea is another diverged at the base of the family with a support of 66%,and Sinofranchetia is the next basal genera with a support of 88%.Boquila Decne.and Lardizabala Ruiz & Pav.are not supported as sister group.Core Lardizabalaceae consists of Holboellia,Akebia,Stauntonia DC.and Archakebia Wu,Chen & Qin with a bootstrap support of 72%.Archakebia is sister to Akebia with a high bootstrap support of 89%.The two species of Akebia,Akebia trifoliata(Thunb.)Koidz.and Akebia trifoliata(Thunb.) Koidz.subsp,australis(Diels) T.Shimizu are well supported by a bootstrap support value of 90%.The results is consistent with the new classifications which combined molecular and morphological data,Sargentodoxa is different from other Lardizabalaceae and should be treated as a subfamilial rank within Lardizabalaceae.5)Character evolutionThe floral organ arised in whorl pattern,or initiated in whorl(three organs formed successively in each whorl) are plesiomorphy,the irregular pattern in Sargentodoxa is automorphic.The floral organs show destiny number is plesiomorphy,variety number in perianth,androecium,and abnormal increase carpels in Sargentodoxa is automorphic,as well as the reduce number in perianth and the increase number in carpels in Akebia.Bicyclic initiation of the sepal is plesiomorphy,whereas monocyclic or more than bicyclic are apomorphic.The petal is the results of many times evolution, the petal morphogenesis and development is the same in Sargentodoxa,Sinofranchetia and Holboellia,retarded development.Contrast to it,there is no petal primordium appeared in Decaisnea and Akebia.Six free androecia is plesiomorphy,and the filament connect into a tube is in Decaisnea apomorphic.Three conduplicate carpels is plesiomorphy,whereas more than 90 ascidium carpels in Sargentodoxa is automorphic.Outer integuments initiate semi-annularly is plesiomorphy,whereas the outer integuments initiate annularly in Holboellia is automorphic.The outer integument becomes hood-shaped in maturity is plesiomorphy,and the copular-shaped outer integument in Sargentodoxa is automorphic or apomorphic.The ovule without appendage is plesiomorphy,and the raphe-shaped appendage in Sinofranchetia is automorphic.The ternate fractionation of leaf primordium in the Lardizabalaceae is plesiomorphy,thus, ternate-acropetal and ternate-basipetal are apomorphic which are derived from the ternate.The ternate compound leaf in Sinofranchetia and Sargentodoxa is plesiomorphy,the pinnate compound leaf in Decaisnea and the palmate or trifoliolate compound leaf in Akebia and Holboellia are apomorphic.According to the results above,comparing the floral morphogenesis in Decaisnea and Sinofranchetia to other genera in Lardizabalaceae,there are many different developmental features between them,Decaisnea and Sinofranchetia are isolated basal group in Lardizabalaceae for their primary characters which imply their different evolutional and diverged route,Sargentodoxa showed more primary characters than Decaisnea and Sinofranchetia,and it is differ from other Lardizabalaceae in floral morphogenesis,ovule morphogenesis,leaf ontogeny and other aspects, such as numerous carpel,uniovulate etc.The three genera have isolated systematic position and are the basal group in Lardizabalaceae.Our observation,together with evidence from anatomy, morphology,palynology,embryology,and molecular data,we agree with the classification of Lardizabalaceae by Wang(2007),suggested give Sargentodoxa a subfamilial rank;Lardizabalaceae consist of Sargentodoxoideae(Hutch.) Thorne & Reveal and Lardizabaloideae Kostel, Lardizabaloideae includes Decaisneeae Reaub.,Sinofranchetieae H.N.Qin & Y.C.Tang,and Lardizabaleae.