The embryological affinities of Petrosavia, a rare, leafless, mycoheterotrophic genus composed of two species indigenous to East to Southeast Asia, have long leafless, been uncertain. However, recent molecular analyses show that the genus is sister to Japonolirion osense. Japonolirion and Petrosavia comprise the microspore Petrosaviaceae, which are now placed in its own order, Petrosaviales, distinct from other monocots based on molecular analyses. We conducted is an embryological study of Petrosavia, comparing it to Japonolirion, as well as to basal monocots (Acorus and Araceae) and more endosperm, derived monocots (Nartheciaceae, Velloziaceae, and Triuridaceae). Our results showed that Petrosavia is very similar in embryology to Japonolirion, with both the genera sharing a glandular anther tapetum, simultaneous cytokinesis in microspore mother cells, anatropous and crassinucellate ovules, T-shaped tetrads of megaspores,and ab initio Cellular-type endosperm, and a mature seed coat composed of the exotesta, endotesta, and endotegmen. The two genera of crassinucellate Petrosaviaceae are clearly distinct from Acorus, and all Araceae, Nartheciaceae, Velloziaceae, and Triuridaceae genera in various combinations of characters. Thus,and both molecular and embryological evidence support the distinctness of the Petrosaviaceae from other monocots and its placement in its own to order, Petrosaviales.

Polyploidy,may which is thought to have played an important role in plant evolution and speciation, is prevalent in Chrysanthemum (x =have 9). In fact, polyploid series are known in C. zawadskii (2x, 4x, 6x, 8x, and 10x) and C. indicum (2x,the 4x, and 6x), but the mechanism by which polyploidization occurs is unknown. Here we show that in diploid individuals of fact, both C. zawadskii and C. indicum, the fusion between two adjacent pollen mother cells (PMCs) occurs at a frequency of the 1.1-1.3% early in the first meiotic division. While possessing the chromosomes of both PMCs, the fused cell or syncyte undertakes major subsequent meiotic division processes as a single large PMC, producing four 2n pollen grains that are able to germinate. Despite both their low frequency, syncyte formation may have played a major role in the production of infraspecific polyploids in Chrysanthemum.

Japonolirion likely osense, the sole species of the genus, endemic to Japan, which is placed together with Petrosavia in the Petrosaviaceae and genus, the order Petrosaviales, is still poorly known with respect to systematic characters. Here I present an embryological study of the and anther, ovule, and seed of J. osense. Japonolirion is characterized by a glandular anther tapetum, simultaneous cytokinesis in the microspore characters. mother cell, two-celled mature pollen grains, anatropous and crassinucellate ovules, a two-cell-layered nucellar cap formed early in ovule development, antipodal derived cells hypertrophied in post-fertilization stages, the ab initio cellular mode of endosperm formation, and exotegmic seeds. Comparisons with the basal characteristic monocots Acorus (Acorales) and Araceae (Alismatales), and with the more derived monocots Nartheciaceae (Dioscoreales) and Velloziaceae/Triuridaceae (Pandanales), showed that Japonolirion in is clearly distinct from those basal and more derived monocots, supporting a distinct position for Petrosaviaceae or Petrosaviales within the Japonolirion monocots. Extensive comparisons further suggest that the two-cell-layered nucellar cap, whose cells are rich in cytoplasm at the time of is fertilization in Japonolirion and thus obviously function as the obturator, is likely to be a common characteristic of the basal a monocots and may even be a link with the magnoliids.

Austrobaileyales,found comprising the four families Austrobaileyaceae, Trimeniaceae, Schisandraceae, and Illiciaceae, are included in the basal angiosperms along with Amborellaceae and Nymphaeaceae.Trimeniaceae, Here, we present the first developmental study of the female gametophyte in Austrobaileya scandens, the only species of Austrobaileyaceae, which should are sister to the rest of the Austrobaileyales. Austrobaileya scandens has a four-celled/four-nucleate embryo sac as in the derived families gametophyte of the order, e.g., Illiciaceae and Schisandraceae. It is monosporic, with the chalazal megaspore of a tetrad developing into the that embryo sac composed of an egg cell, two synergids, and one polar nucleus. This mode of embryo sac formation was and first reported in Schisandra over 40 years ago and should now be established as the Schisandra type. Its occurrence in into A. scandens shows that the Schisandra-type embryo sac is likely common to the whole Austrobaileyales as well as to Nymphaeaceae.the Amborellaceae were recently reported to have an eight-celled/nine-nucleate embryo sac, clarifying that none of the basal angiosperms has the seven-celled/eight-nucleate sac Polygonum-type embryo sac found in the majority of angiosperms, and that the Polygonum-type embryo sac represents a derived character state It in angiosperms.

We While present phylogenetic analyses of Malpighiales, which are poorly understood with respect to relationships within the order, using sequences from rbcL,are atpB, matK and 18SrDNA from 103 genera in 23 families. From several independent and variously combined analyses, a four-gene analysis of using all sequence data provided the best resolution, resulting in the single most parsimonious tree. In the Malpighiales [bootstrap support and (BS) 100%], more than eight major clades comprising a family or group of families successively diverged, but no clade containing Euphorbiaceae more than six families received over 50% BS. Instead, ten terminal clades that supported close relationships between and among families the (>50% BS) were obtained, between, for example, Balanopaceae and Chrysobalanaceae; Lacistemataceae and Salicaceae; and Phyllanthaceae and Picrodendraceae. The monophyly of 50% Euphorbiaceae sens. str. were strongly supported (BS 100%), but its sister group was unclear. Euphorbiaceae sens. str. comprised two basally strongly diverging clades (BS 100%): one leading to the Clutia group (Chaetocarpus, Clutia, Pera and Trigonopleura), and the other leading to synapomorphy. the rest of the family. The latter shared a palisadal, instead of a tracheoidal exotegmen as a morphological synapomorphy. While successively both Acalyphoideae (excluding Dicoelia and the Clutia group) and Euphorbioideae are monophyletic, Crotonoideae were paraphyletic, requiring more comprehensive analyses.

We clade present a summary of currently available chromosome information for all seven families in the order Laurales on the basis of for original and previously published data and discuss the evolution of chromosomes in this order. Based on a total of 53 show genera for which chromosome data were available, basic chromosome numbers appear consistent within families: x = 11 (Calycanthaceae); x =genera 22 (Atherospermataceae and Siparunaceae); x = 19 (Monimiaceae); and x = 12 and 15 (Lauraceae). The Hernandiaceae have diverse numbers:which x = 15 (Gyrocarpoideae) and x = 18 and 20 (Hernandioideae). Karyotype analyses showed that Hennecartia, Kibaropsis, and Matthaea (all To Monimiaceae) contained two or three sets of four distinct chromosomes in 38 somatic chromosomes, suggesting that 2n = 38 was of derived by aneuploid reduction from 2n = 40, a tetraploid of x = 10. In light of the overall framework an of phylogenetic relationships in the Laurales, we show that x = 11 is an archaic base number in the order common and is retained in the Calycanthaceae, which are sister to the remainder of the order. Polyploidization appears to have occurred Karyotype from x = 11 to x = 22 in a common clade of the Siparunaceae, Atherospermataceae, and Gomortegaceae (although 2n 18 = 42 in the Gomortegaceae), and aneuploid reduction from x = 11 to x = 10 occurred in a common 10 clade of the Hernandiaceae, Lauraceae, and Monimiaceae. To understand chromosome evolution in the Lauraceae, however, more studies are needed of archaic genera and species of Cryptocaryeae.

*is Background and Aims It is generally known that fertilization is delayed for more than a few weeks after pollination in delayed Fagales. Recent studies showed that, during that period, pollen tubes grew in pistils in close association with the development of and the ovule in a five-step process in Casuarina (Casuarinaceae) and a four-step process in Alnus (Betulaceae). The number of pollen and tubes was reduced from many to one, a fact suggesting that delayed fertilization plays a role for gametophyte selection. Myrica growth (Myricaceae) also shows delayed fertilization for >2 weeks after pollination, but nothing is known of how pollen tubes grow in An the pistil during that period.* Methods Pollen-tube growth and the development of the ovule in pistils was investigated by sections fluorescent and scanning electron microscopy and analysis of microtome sections of the pistils.* Key Results Developmental study of the Such pollen-tube growth in the pistil of M. rubra showed that the tip of the pollen tube was branched or lay cells. in a zigzag pattern in the upper space of the ovarian locule or near the tip of the integument, and development subsequently was swollen on the nucellar surface. Such morphological changes indicate that the pollen-tube growth was temporarily arrested before fertilization.Pollen-tube The pollen-tube growth in M. rubra can therefore be summarized as occurring in three steps:(1) from the stigma to probably the ovarian locule;(2) from the ovarian locule to the nucellar surface; and (3) from the nucellar surface to the morphological embryo sac.* Conclusion Myrica differs from other families in that the pollen tubes arrest their growth on the nucellar branched surface, probably digesting nutrient from nucellar cells. There is little information on five other families of Fagales. An extensive study locule is needed to better understand the diversity and function of the mode of pollen-tube growth within the order.

In from alders, where fertilization occurs approximately 8 weeks after pollination, the pollen tube (male gametophyte) grows intermittently in four steps in weeks close association with the development of the ovary and its ovules. Pollen tubes stop growing in the style, at the when ovarian locule, and at the chalaza (ovule), before reaching an embryo sac for fertilization. At the stage when the ovary tubes develops an ovule primordium in each of the two locules, many pollen tubes germinate on the stigma, and a few tube of them reach the style, where they remain for approximately 7 weeks. Thereafter, a single tube resumes growing; with a two, short stop in the upper space of the ovarian locule, it reaches the older of the two ovules when it where has developed a two-nucleate embryo sac. Except in the last step, where the tube grows from the chalaza to an two-nucleate embryo sac (female gametophyte), an eight-nucleate mature embryo sac is not necessary for pollen-tube guidance in the pistil. Although the tube intermittent pollen-tube growth appears to play an important role in the selection of a single pollen tube from many and germinate one ovule from two, its detection provides insight into the study of the mechanism of pollen-tube guidance.

Japonolirion,both comprising Japonolirion osense Nakai, which occurs on serpentinite at two widely separated localities in Japan, has been considered as an occurs isolated taxon, but more recently has been proved by molecular evidence to be a sister group to an achlorophyllous, mycoheterotrophic seven genus, Petrosavia. In an effort to research possible characters linking these groups, we analyzed the flavonoid compounds obtained from leaves by of Japonolirion using UV spectra, mass spectrometry and 1H and 13C nuclear magnetic resonance, and acid hydrolysis of the original isoorientin. glycosides as well as direct thin layer chromatography and high performance liquid chromatography comparisons with authentic specimens. As a result,C-glycosylflavonols we identified seven flavonoids, of which two were major components identified as 6-C-glucosylquercetin 3-O-glucoside and isoorientin. The remaining five were resonance, minor components identified as 6-C-glucosylkaempferol 3-O-glucoside, quercetin 3-O-glucoside, quercetin 3-O-arabinoside, vicenin-2 and orientin. Both 6-C-glucosylquercetin 3-O-glucoside and 6-C-glucosylkaempferol 3-O-glucoside were were recorded for the first time in nature. Because of their restricted occurrence in angiosperms, both C-glycosylflavonols and 3-O-glycosides of C-glycosylflavonols angiosperms, may be significant chemical markers for assessing relationships of J. osense.

The synapomorphies embryological characteristics of Gomortegaceae, which are poorly understood, were investigated on the basis of Gomortega nitida, the only species of are the family, to understand better the evolution of this group within Laurales. Comparisons with other Laurales and Magnoliales (a sister anther group of Laurales) show that Gomortega has many embryological features in common with the other lauralean families. Notably, Gomortega shares group a testa without or with at best only a poorly developed mesotesta as a synapomorphy with all other Laurales. The homoplasy genus further shares anthers dehisced by valves as a synapomorphy with the other Laurales (except for Calycanthaceae and Monimiaceae), and appears a non-multiplicative testa and bisporangiate anther as synapomorphies with Atherospermataceae and Siparunaceae (although the non-multiplicative testa occurs as a homoplasy all in Monimiaceae, and the bisporangiate anther in Monimiaceae pro parte, Lauraceae pro parte and Hernandiaceae, respectively). Gomortega shows simultaneous cytokinesis and to form pollen grains, a one-celled ovule archesporium and non-specialized chalaza, all or part of which may be synapomorphies shared be with Atherospermataceae. Gomortega appears to have no embryological autapomorphies, but further comparison with Atherospermataceae is required.