Fertilization Following Pollination Predominantly Decreases Phytocannabinoids Accumulation and Alters the Accumulation of Terpenoids in Cannabis Inflorescences

In the last decades, growing evidence showed the therapeutic capabilities of Cannabis plants. These capabilities were attributed to the specialized secondary metabolites stored in the glandular trichomes of female inflorescences, mainly phytocannabinoids and terpenoids. The accumulation of the metabolites in the flower is versatile and influenced by a largely unknown regulation system, attributed to genetic, developmental and environmental factors. As Cannabis is a dioecious plant, one main factor is fertilization after successful pollination. Fertilized flowers are considerably less potent, likely due to changes in the contents of phytocannabinoids and terpenoids; therefore, this study examined the effect of fertilization on metabolite composition by crossbreeding (-)-Δ9-trans-tetrahydrocannabinol (THC)- or cannabidiol (CBD)-rich female plants with different male plants: THC-rich, CBD-rich, or the original female plant induced to develop male pollen sacs. We used advanced analytical methods to assess the phytocannabinoids and terpenoids content, including a newly developed semi-quantitative analysis for terpenoids without analytical standards. We found that fertilization significantly decreased phytocannabinoids content. For terpenoids, the subgroup of monoterpenoids had similar trends to the phytocannabinoids, proposing both are commonly regulated in the plant. The sesquiterpenoids remained unchanged in the THC-rich female and had a trend of decrease in the CBD-rich female. Additionally, specific phytocannabinoids and terpenoids showed an uncommon increase in concentration followed by fertilization with particular male plants. Our results demonstrate that although the profile of phytocannabinoids and their relative ratios were kept, fertilization substantially decreased the concentration of nearly all phytocannabinoids in the plant regardless of the type of fertilizing male. Our findings may point to the functional roles of secondary metabolites in Cannabis.

Anatomical Characteristics of Petalized Anther Abortion in Male Sterile Camellia oleifera Plants

Petalized anther abortion is an important characteristic of male sterility in plants. The male sterile plants (HB-21) evincing petalized anther abortion previously discovered in a clone population of the Camellia oleifera cultivar Huashuo by our research group were selected as the experimental material in this study. Using plant microscopy and anatomic methods and given the correspondence between external morphology and internal structure, we studied the anatomic characteristics of petalized anther abortion (with a fertile plant as the control group) in various stages, from flower bud differentiation to anther maturity, in hopes of providing a theoretical basis for research on and applications of male sterile C. oleifera plants, a new method for the selection of male sterile C. oleifera cultivars, and improvements in the yield and quality of C. oleifera. In this study, the development of anthers in C. oleifera was divided into 14 stages. Petalized anther abortion in male sterile plants was mainly initiated in the second stage (the stage of sporogenous cells). Either the petalized upper anther parts did not form pollen sacs, or the entire anthers did not form pollen sacs. The lower parts of some anthers could form deformed pollen sacs and develop, and these anthers could be roughly divided into two types: fully and partially petalized anthers. Abnormal callose and the premature degradation of the tapetum occurred in the pollen sacs formed by partially petalized anthers during the development process, resulting in the absence of inclusions in the pollen grains formed. Small quantities of mature pollen grains withered inward from the germinal furrows, exhibiting obvious abortion characteristics. The relative in vitro germination rate of the pollen produced by the partially petalized anthers of sterile plants was 11.20%, and the relative activity of triphenyltetrazolium chloride was 3.24%, while the fully petalized anthers did not generate pollen grains. Either the petalized anthers in male sterile plants did not produce pollen, or the vitality of the small amounts of pollen produced by sterile plants was very low compared with that of fertile plants. Such male sterile plants could be used to select correct clones and have good prospects for application in production.

Weltrichia magna sp. nov., a new record for the Middle Jurassic of Oaxaca, México

The Jurassic locality San Juan Mixtepec (Zorrillo Formation in the state of Oaxaca) contains fossil plants of the order Bennettitales, mainly of the genus Zamites, as well as reproductive structures of the genera Williamsonia, Williamsoniella and Weltrichia, but male reproductive structures of the latter genus are scarce and almost restricted to the south of Mexico; they have also been reported in the Triassic of the north of Mexico. Here we report a new record for this locality and a new species of male reproductive structure of the genus Weltrichia. We recovered half of an adpression in fine-grained sandstone with the positive and negative of the adaxial part of the male reproductive structure, which when open measures 22.6 cm in diameter. A reconstruction suggests the presence of ten centrifugal rays that become thinner towards the acute apex and are fused in a central basal cup. The structure exhibits complete centrifugal rays with basal structures that are interpreted as insertion sites for pollen sacs. We employed acetate peel, mechanical separation and hydrofluoric acid (HF) maceration techniques for extraction of anatomical samples. We compared 13 morphological and 10 anatomical characters with previous records from localities in México, Europe, Asia and other parts of the world. We observed epidermal cells and syndetocheilic stomatal apparatuses, which corroborate an epidermal affinity to the Bennettitales. This new record would be the largest male reproductive structure found in the region thus far, and increases the distribution of Weltrichia in the Jurassic of Oaxaca.

Valviloculus pleristaminis gen. et sp. nov., a Lauralean fossil flower with valvate anthers from mid-Cretaceous Myanmar amber

The flower described here as Valviloculus pleristaminis, a new genus and species of fossil angiosperms, was obtained from Myanmar amber deposits dating to the mid-Cretaceous period. The flower is staminate, with an ovoid, hollow floral cup. The perianth consists of 6 tepals, one of which was lost prior to preservation. Numerous helically arranged stamens are borne at the summit of the flower. The anthers are bilocular, with pollen sacs that dehisce by laterally hinged valves. The tip of the connective bears a cup-shaped appendage. The gynoecium is represented only by a cluster of vestigial styles centered among the stamens. The fossil is provisionally assigned to order Laurales, its closest affinities being with the families Monimiaceae and Atherospermataceae.

IMPACT OF PHYSICAL MUTAGENS ON THE MALE GAMETOPHYTE OF THE TEA PLANT FOR ITS FURTHER USE IN HYBRIDIZATION

The migration of the radioisotopes - P32 and S35 from the soil to the tea plant (flowers) was studied. It is shown that their accumulation intensity in pollen sacs increases in proportion to the dose and reaches its maximum in the P32 variant after using a 8.0 MBq / ml dose. The migration intensity was the lowest in the 2.0 MBq / ml variant (0.14-0.223 MBq / 100 mg). It is estimated that P32 and S35 have significantly affected the vitality of tea plant pollens through the anomalies of their development. After using 2.0 and 4.0 MBq / ml doses, the vitality of the pollen is reduced in proportion to the dose and the development anomalies increase. Particulalry, the viability of pollen decrease compared to the control group, but the frequency and range of development anomalies increases. These include the slow development of the plant or the acceleration of the development of the primary nucleus, polyspermia, undeveloped pollen tube, etc. The use of processed P32 and S35 tea pollens in hybridization significantly increases the frequency of new formations and results in variability in the domination of signs. Among the new formations include the induction of haploids and triploids.

A new species of Amentotaxus (Taxaceae) from China, Vietnam, and Laos

A new species Amentotaxus hekouensis L.M. Gao is described as new to science from Hekou, Yunnan of China, Lao Cai of Vietnam and Xiang Khouang of Laos. The new species is similar to A. argotaenia (Hance) Pilg. in linear or linear-lanceolate leaves, stomatal bands white and microsporophylls 6–8, each with 4–6 pollen sacs, but differs from the latter by its larger leaf size with 8–12.5 cm × 0.9–1.4 cm (vs. 2–11 cm × 0.5–1.1 cm in A. argotaenia), long acuminate leaf apex (vs. rounded to sharply triangular in A. argotaenia), stomatal bands with 25–30 rows (vs. 15–25 rows in A. argotaenia), stomatal bands equal to or slightly narrower than marginal bands (vs. narrower than marginal bands in A. argotaenia); pollen-cone racemes borne 1–2 (vs. 2–4 (10) in A. argotaenia), cones in 12–16 pairs (vs. ca. 12 pairs in A. argotaenia). Its distinctive nature has also been confirmed through DNA barcoding analysis of this genus. The new species is provisionally assessed as endangered (EN) due to its restricted distribution, small population size and the prevalence of habitat destruction within its range.

Timing of Reproductive Organs Maturity in Proterandrous Malva sylvestris L.

Flower development of protandrous species Malva sylvestris L. was divided into 12 stages, as revealed by applying histological and scanning electron microscope techniques. Flower development started with the conversion of apical meristem into floral meristem. Initiation of male organ primordia started before that of female organ. Five rounded structures called corolla/androecium units differentiated from floral meristem, on which stamen primordia emerged. When pollen mother cells exist in the pollen sacs, initiation of carpels starts from floral meristem. Concurrent with the termination of meiosis in pollen mother cells, ten loculed ovary comed in view. Simultaneously with the occurrence of vacuoleted pollen grains, megaspore mother cell becomes visible in the nucellar tissue. Concominant with the existence of two celled-pollen grains, the style was formed and ovule becomes anatropous. When pollen grains are shed in male phase, ten branched stigma appeared on the upper part of the style, but receptive surface was not fully formed to accept pollen grains. Female phase is characterized by the opening of stigmatic branches with papillate receptive surface. Timing of reproductive organs maturity overlapped for a while, thus, the reproductive stragey of M. sylvestris was incomplete proterandry.

Cecilanthus polymerus, a novel multiparted flower from the mid-Cretaceous Rocky Point locality, Maryland

A flower from the early Cenomanian of northeastern Maryland, Cecilanthus polymerus gen. et sp. nov., is described using SEM and synchrotron X-ray microtomography. The flower has >20 strap-shaped tepals, ca. 50 spatulate stamens with embedded adaxial pollen sacs and possibly H-valvate dehiscence, and ca. 100 more-or-less plicate carpels. Floral phyllotaxis is whorled, with >10 parts per whorl, but slightly irregular. Pollen and ovules are not preserved, but locule shape suggests that the carpels are uniovulate. Similar characters occur in extant Magnoliales and the basal ANITA grade, but never in combination. In an attempt to resolve these ambiguities, we performed morphological phylogenetic analyses, with the arrangement of extant taxa constrained to trees based primarily on molecular data. With anther dehiscence and ovule number treated as unknown, Cecilanthus has several most-parsimonious positions: nested in Nymphaeales, nested in Magnoliales, sister to Laurales, and sister to Chloranthaceae. However, scoring anther dehiscence as H-valvate and ovule number as = 1, increases support for a position in Magnoliales. Cecilanthus demonstrates that the early radiation of angiosperms produced floral morphotypes unlike those in any surviving taxa, and it illustrates the value of characters such as pollen morphology and seed anatomy for phylogenetic placement of floral mesofossils.

Structure of anther heads in some Trifolium L. species

The species of the genus <i>Trifolium</i> differ by the number of pollen sacs in stamen heads. Some have only two, other four and in some species there arę two, three or four pollen sacs. The opinion of some authors (Schnarf 1931, Davis 1966) that from this point of view this genus is uniform is wrong. There is some dependence between the chromosome number (2n) and the number of pollen sacs. For two species - <i>T. carmeli</i> and <i>T. desvauxii</i> - the chromosome numbers 2n=14 were established for the first time.

Pilostyles boyacensis, a new species of Apodanthaceae (Cucurbitales) from Colombia

Pilostyles boyacensis, a new Apodanthaceae from Colombia, is described and illustrated. The species was found between 2000 and 2415 m elevation, parasitizing Dalea cuatrecasasii (Fabaceae:Papilionoideae) in dry interandean valleys of the Colombian Eastern Cordillera. The species can be distinguished from its congeners by the monoecious condition, the small size (1.5–2.5 mm in diameter) of the almost cleistogamous and tubular flowers, and the presence of five or six white petals and three to four rows of pollen sacs. The locations of the new species are among the highest for the genus in the Americas, and are altitudinally isolated from the tetrapetalous P. thurberi, from S United States and Mexico, P. mexicana from Mexico, Honduras and Guatemala, P. blanchetii from Jamaica, Cayman Islands, Costa Rica, Panama, Venezuela, Brazil and N Argentina, and P. berteroi from Peru, Bolivia, Chile and Argentina, none of which (except P. thurberi) parasitizes Dalea. The Dalea-host life style suggests that P. boyacensis is closely related to P. thurberi. As in other Pilostyles, the new species exhibits isophasic growth, but unlike most species of the genus, both staminate and carpellate flowers are often found adjacent in the same flower row. The species sets flowers and fruits continuously at least from late November to late March, which corresponds to the driest months of the year in these areas. Camponotus ants and a black shield bug are frequent visitors to flowers and fruits, and might play an active role in seed dispersal.