The Study On Systematic Position Of Paeoniaceae

Eight groups of Paeoniaceae and one group of Pinaceae were studied roundly about the relationship between carpel and carpellary disc, the relationship between ovuliferous scale and bract scale, relationship between stamen and leaf, the morphological characters and The developmental process of the tubiform petal from stamen primordia , etc.. The results show:(1) In the highflower of prolification flower, each carpel is always accompanied by itself carpellary disc, they have common basic tissue that differs from the tissue of receptacle, and they have common system of vascular bundle. When the carpellary primordia heteromorphically develop into sepal or tepal, the heteromorphical carpellary discs or its trances can often be found in the dorsal base of the organs. In lowerflower of prolification flower and non-prolification flower, the carpellary discs of 5 carpels usually connect into ringlike structure, but the discs of the two neighboring carpels do not fuse completely and there is a small split between each them at the early stage of carpel ontogeny. After researching the morphology, anatomy and development process of carpel and carpellary disc, we put forward a viewpoint that the carpellary disc of Paeonia is appendant organ of carpel instead of protuberantia of receptacle.In the female cone of Pinus. tabulaeformis Carr., each ovuliferous scale is always accompanied by itself bract scale, i. e. one ovuliferous scale and it's barct scale make of separated group. At the initial stage of ovuliferous scale ontogeny, it's primordium is developed from the two or three layer's cells at surface of surface. And they have common basic tissue that differs from the tissue of axis. Further more, there is special cavea in the common basic tissue of ovuliferous scale and bract scale. This cavea structure is mutual. After researching the morphology, anatomy and development process of the ovuliferous scale and the barct scale In the female cone of Pinus, we have a conclusion that the the bract scale of Pinus. tabulaeformis Carr. is appendant organ of the ovuliferous scale.Contrast morphology and development process of the carpel and carpellary disc in Paeonia with the ovuliferous scale and bract scale in Pinus,we have some conclusion as follow:①The carpel and carpellary disc in Paeonia and the ovuliferous scale and bract scale in Pinus respectively developed from a primordium.②The carpel and carpellary disc in Paeonia differed from the ovuliferous scale and bract scale in Pinus on process of differentiation and development.③They have similar structure at mature stage.Based on all of above, we can concluded that there is some relationship between Paeonia and Pinus. There is three states: First is that the plants of Paeonia derived from the plants of Pinus. Which is to say, the carpel and carpellary disc in Paeonia respectively derived form the ovuliferous scale and bract scale in Pinus. The second is that Paeonia and some gymnosperm (such as Pinus) derived from the same ancestor, and preserved the similar reproductive organ structure of ancestor. The third possibility is the convergent evolution. But this possibility can be precluded because of similarity of their development process. And we do incline towards the second theory.(2) The stamen have a series of remarkable characters in genus Paeonia.①There is the phenomenon that all stamens of one flower congregate into obvious five or six group in genus Paeonia.②The anatomic structure is bifurcated vascular bundle in basic tissue of one group of stamens.③The mode, rate, time and position of the stamen primordia differ distinctly from its neighboring organ, such as petal primordia and carpel primordial in genus Paeonia。④The variety range among number of stamen. And stamen can heteromorphically develop into sepal. On the basis of a series of result, contrast them to constitution, structure and development process of leaves , indeterminacy of leaflit's number, divaricator pattern of nerve. And contrast with mode, rate, time and position of petal primordial and carpel primordial in the round. We put forward a viewpoint that a stamen equate to a leafit, and a group of stamens is evolved from a leaf. The relationship between stamen and leaf is distinct. The distinct relationship imply that Paeonia is barbarous on evolution。(3) In this study, the morphological characters of tubiform petals from stamen primordia in Paeonia suffruticosa, P. rockii, P. ludlowii, P.decomposita, P.ostii, P.qiui, P.delavayi and P. lactiflora have carefully been surveyed. Furthermore, the quantity of tubiform petals from stamen primordia only occurred in P. suffruticosa, P. rockii and P. lactiflora have been measured, and their anatomic construction have been examined. The results as following:①The rate of tubiform petals from stamen primordia is quite low and it's morphological characters is simple in the flowers of P. suffruticosa and P. rockii. By contrast, the rate of tubiform petals from stamen primordia is obviously higher and it's morphological characters is more complex in the flowers of P. lactiflora.②From bottom to top, there is a series transformation in the anatomic construction of tubiform petals from stamen primordia. In contrast to the anatomic construction of tubiform petals from stamen primordia in P. suffruticosa and P. rockii, P. lactiflora's is more diverse.③Sustained differentiation of the lateral meristem of the vascular bundle and the increase of the quantity of vascular bundle play a key role during the developmental process transformed the stamen primordium into tubiform petal.④The developmental process of the tubiform petal from stamen primordium can be divided into following four stages, i.e. the primordium differentiation, the transformation development, the formation of tubiform petal and the maturation of tubiform petal.⑤We only found tubiform petal in cultivar of Paeonia, such as Paeonia suffruticosa, P. rockii and P. lactiflora. It also show that the plants of the genus have synchronously barbarism and plasticity. i. e. they are at stage of consuming differentiation during the process of evolution.The relationship between the carpel and carpellary disc in Paeonia and the ovuliferous scale and bract scale in Pinus, the relationship between stamen and leaf in Paeonia , display that peaonia is primitive group. Of course, this also show the relation systematic position between peaonia and pinus. And connected with a series of embryological characters, we may consider that peaonia is one of most primal group, it's classification grade is subclass. And it should be at bottom of angiosperm's systematic tree. The third display that the plants of peaonia have a series of characters about organ translation. It's reproductive organ transform into phylloid organ. It looks that it is the backward transformation. Combined with the origin of angiosperm, ie the flower is a shrinkage branch, and all organs of flower are metamorphosis of leaf. For the higher evolution level groups, this reversible transformation is impossible, but it is not only frequent, but also very easy. So we consider that the transformation character preserved from the acrimony differentiation stage. So it display the primitives of peaoniaceae at another aspect.