Silene | |
---|---|
Silene dioica (red campion) | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Order: | Caryophyllales |
Family: | Caryophyllaceae |
Genus: | Silene L. |
Species | |
Synonyms [1] | |
List
|
Silene is a genus of flowering plants in the family Caryophyllaceae. Containing nearly 900 species, [1] it is the largest genus in the family. [2] Common names include campion and catchfly. Many Silene species are widely distributed, particularly in the northern hemisphere. [2]
Members of this genus have been the subject of research by preeminent plant ecologists, evolutionary biologists, and geneticists, including Charles Darwin, Gregor Mendel, Carl Correns, Herbert G. Baker, and Janis Antonovics. Many Silene species continue to be widely used to study systems, particularly in the fields of ecology and evolutionary biology. [3] The genus has been used as a model for understanding the genetics of sex determination for over a century. Silene species commonly contain a mixture of hermaphroditic and female (or male-sterile) individuals (gynodioecy), and early studies by Correns showed that male sterility could be maternally inherited, [4] [5] an example of what is now known as cytoplasmic male sterility. Two independent groups of species in Silene have evolved separate male and female sexes (dioecy) with chromosomal sex determination that is analogous to the system found in humans and other mammals. [6] [7]
Silene flowers are frequently visited by flies, such as Rhingia campestris . [8] Silene species have also been used to study speciation, host-pathogen interactions, biological species invasions, adaptation to heavy-metal-contaminated soils, metapopulation genetics, and organelle genome evolution. [3] Notably, some members of the genus Silene hold the distinction of harboring the largest mitochondrial genomes ever identified. [9]
Silene is the feminine form of Silenus, an Ancient Greek woodland deity who was a companion and tutor to the wine god Dionysus. [10]
Silene was originally described by Linnaeus. [1] Divisions of the genus into subgenera or sections before 2003 do not seem to be well-supported by molecular evidence. [2]
The genus Lychnis is closely related to (and sometimes included in) Silene. [11] [12] When treated as a distinct genus, it can often be differentiated by the number of flower styles (five in Lychnis' and three in Silene), the number of teeth of the seed capsule (five in Lychnis' and six in Silene), and by the sticky stems of Lychnis.
Sexual systems vary across species. Most Silene species are hermaphroditic representing 58.2% of Silene species, 14.3% are dioecious, 13.3% gynodioecious, and 12.2% are both gynodioecious and gynomonoecious. Trioecy, andromonoecy, and gynomonoecy have also been reported but are extremely rare. [13]
Lychnis is also the common name of Hadena bicruris , a species of noctuid moth. The larva of this moth feeds on Silene (formerly Lychnis) species, as do some other Lepidoptera including cabbage moths (recorded on Silene chalcedonica ), grey chi and case-bearers of the genus Coleophora including C. albella (feeds exclusively on Silene flos-cuculi ).
Many species of Silene are in cultivation for perennial gardens. [14] Some have gained the Royal Horticultural Society's Award of Garden Merit, including Silene flos-jovis and Silene schafta . [15]
Silene undulata (syn. S. capensis) is known as iindlela zimhlophe ("white paths") by the Xhosa of South Africa. A Xhosa diviner identifies and collects the plant from the wild. The roots are ground, mixed with water, and beaten to a froth, which is consumed by novice diviners during the full moon to influence their dreams. They also take it to prepare for various rituals. The root has such a strong, musky essence that the diviners who consume it exude the scent in their sweat. [16]
Silene vulgaris , or bladder campion, is eaten in some Mediterranean countries. Young leaves may be eaten raw, and mature leaves are boiled, fried, stewed or mixed into dishes such as risotto.
Fossil †Silene microsperma seeds from the Chattian stage of the Oligocene have been found in the Oberleichtersbach Formation in the Rhön Mountains of central Germany. [17]
Sex is the trait that determines whether a sexually reproducing organism produces male or female gametes. Male organisms produce small mobile gametes, while female organisms produce larger, non-mobile gametes. Organisms that produce both types of gametes are called hermaphrodites. During sexual reproduction, male and female gametes fuse to form zygotes, which develop into offspring that inherit traits from each parent.
Selfish genetic elements are genetic segments that can enhance their own transmission at the expense of other genes in the genome, even if this has no positive or a net negative effect on organismal fitness. Genomes have traditionally been viewed as cohesive units, with genes acting together to improve the fitness of the organism. However, when genes have some control over their own transmission, the rules can change, and so just like all social groups, genomes are vulnerable to selfish behaviour by their parts.
A sex-determination system is a biological system that determines the development of sexual characteristics in an organism. Most organisms that create their offspring using sexual reproduction have two common sexes and a few less common intersex variations.
A sex ratio is the ratio of female to males in a population. As explained by Fisher's principle, for evolutionary reasons this is typically about 1:1 in species which reproduce sexually. However, many species deviate from an even sex ratio, either periodically or permanently. Examples include parthenogenic species, periodically mating organisms such as aphids, some eusocial wasps, bees, ants, and termites.
Haldane's rule is an observation about the early stage of speciation, formulated in 1922 by the British evolutionary biologist J. B. S. Haldane, that states that if — in a species hybrid — only one sex is inviable or sterile, that sex is more likely to be the heterogametic sex. The heterogametic sex is the one with two different sex chromosomes; in therian mammals, for example, this is the male.
Silene chalcedonica, the Maltese-cross or scarlet lychnis, is a species of flowering plant in the family Caryophyllaceae, native to central and eastern Russia, Kazakhstan, Mongolia and northwestern China. Other common names include flower of Bristol, Jerusalem cross and nonesuch.
Dioecy is a characteristic of certain species that have distinct unisexual individuals, each producing either male or female gametes, either directly or indirectly. Dioecious reproduction is biparental reproduction. Dioecy has costs, since only the female part of the population directly produces offspring. It is one method for excluding self-fertilization and promoting allogamy (outcrossing), and thus tends to reduce the expression of recessive deleterious mutations present in a population. Plants have several other methods of preventing self-fertilization including, for example, dichogamy, herkogamy, and self-incompatibility.
Male is the sex of an organism that produces the gamete known as sperm, which fuses with the larger female gamete, or ovum, in the process of fertilization. A male organism cannot reproduce sexually without access to at least one ovum from a female, but some organisms can reproduce both sexually and asexually. Most male mammals, including male humans, have a Y chromosome, which codes for the production of larger amounts of testosterone to develop male reproductive organs.
Silene acaulis, known as moss campion or cushion pink, is a small mountain-dwelling wildflower that is common all over the high arctic and tundra and in high mountains of Eurasia and North America. It is an evergreen perennial flowering plant in the carnation family Caryophyllaceae.
The ZW sex-determination system is a chromosomal system that determines the sex of offspring in birds, some fish and crustaceans such as the giant river prawn, some insects, the schistosome family of flatworms, and some reptiles, e.g. majority of snakes, lacertid lizards and monitors including Komodo dragons. It is also present in some plants, where it has probably evolved independently on several occasions. The letters Z and W are used to distinguish this system from the XY sex-determination system. In the ZW system, females have a pair of dissimilar ZW chromosomes, and males have two similar ZZ chromosomes.
The mechanisms of reproductive isolation are a collection of evolutionary mechanisms, behaviors and physiological processes critical for speciation. They prevent members of different species from producing offspring, or ensure that any offspring are sterile. These barriers maintain the integrity of a species by reducing gene flow between related species.
Cytoplasmic male sterility is total or partial male sterility in hermaphrodite organisms, as the result of specific nuclear and mitochondrial interactions. Male sterility is the failure to produce functional anthers, pollen, or male gametes. Such male sterility in hermaphrodite populations leads to gynodioecious populations.
A sex chromosome is a chromosome that differs from an ordinary autosome in form, size, and behavior. The human sex chromosomes, a typical pair of mammal allosomes, carry the genes that determine the sex of an individual created in sexual reproduction. Autosomes differ from allosomes because autosomes appear in pairs whose members have the same form but differ from other pairs in a diploid cell, whereas members of an allosome pair may differ from one another and thereby determine sex.
Caenorhabditis is a genus of nematodes which live in bacteria-rich environments like compost piles, decaying dead animals and rotting fruit. The name comes from Greek: caeno- ; rhabditis = rod-like. In 1900, Maupas initially named the species Rhabditis elegans, Osche placed it in the subgenus Caenorhabditis in 1952, and in 1955, Dougherty raised Caenorhabditis to the status of genus.
Gynodioecy is a rare breeding system that is found in certain flowering plant species in which female and hermaphroditic plants coexist within a population. Gynodioecy is the evolutionary intermediate between hermaphroditism and dioecy.
Teucrium racemosum, also commonly referred to as either the grey germander or forest germander, is a species of flowering plant in the family Lamiaceae. It is endemic to Australia and is found in all mainland states, the Northern Territory and the Australian Capital Territory. It grows in floodplains, dry lake beds and open woodlands. A perennial herb, it has four-sided, densely hairy stems, narrow egg-shaped leaves, and white flowers usually arranged singly in leaf axils. It grows to be between 15 and 40 cm tall.
Silene conica is a species of flowering plant in the family Caryophyllaceae known by the common names striped corn catchfly and sand catchfly. It grows in dunes and sandy soils and is widespread in Europe and western Asia. It has an annual life history and produces self-compatible hermaphroditic flowers and occasional male-sterile flowers. Like other members of Silene section Conoimorpha, S. conica is readily recognizable based on its bright pink petals and the prominent, parallel veins on its calyx. In contrast to most flowering plants, S. conica appears to have a very rapid rate of mitochondrial mutation, and has the largest mitochondrial genome ever identified.
Silene is a flowering plant genus that has evolved a dioecious reproductive system. This is made possible through heteromorphic sex chromosomes expressed as XY. Silene recently evolved sex chromosomes 5-10 million years ago and are widely used by geneticists and biologists to study the mechanisms of sex determination since they are one of only 39 species across 14 families of angiosperm that possess sex-determining genes. Silene are studied because of their ability to produce offspring with a plethora of reproductive systems. The common inference drawn from such studies is that the sex of the offspring is determined by the Y chromosome.
Gynomonoecy is defined as the presence of both female and hermaphrodite flowers on the same individual of a plant species. It is prevalent in Asteraceae but is poorly understood.
Silene stockenii is a species of flowering plant in the Caryophyllaceae first described in 1973. The specific epithet is named after Christopher Maitland Stocken, who discovered it in 1962 in Bornos. It is native to Spain, where it is endemic to grasslands growing in calcareous soil on formations made from calcarenite west of Cádiz in Andalusia. It is currently listed as critically endangered. In 1993, the number of individuals belonging to this species was estimated to be below 2000.