Perfect Flowers Research Articles

Andromonoecy, flowering and pollination biology of <I>Dorema microcarpum</I> (Apiaceae) in the conditions of the Ferghana Valley (Uzbekistan)

Andromonoecy was described and anthecological features were identified for the first time in Dorema microcarpum, a perennial monocarpic plant endemic to the Western Tien Shan and Northern Pamir-Alai. The research was carried out in the natural conditions of the Chust-Pap adyrs of the Fergana Valley in 2021–2023. The floral unit is shown to be an open tiered raceme of tiered racemes of simple umbels. In powerfully developed plants, paracladia are formed in the lower part of the synflorescence. The duration of flowering of an individual is 10–15 days. Simple umbels in different parts of the synflorescence can form only perfect flowers, or perfect and staminate flowers, or only staminate flowers. In poorly developed plants, simple umbels of lateral racemes from the 6th node form perfect flowers and 1 to 5 staminate flowers; simple umbels of 2–3 lower lateral racemes form only staminate flowers. In powerfully developed plants in the middle and upper parts of synflorescence, almost all simple umbels form only perfect flowers; staminate flowers are observed only on paracladia. The flowering of an individual begins with simple umbels on the lateral racemes located in the middle floral unit, namely from the 6th to the 9th nodes and occurs divergently: first, the middle and upper parts of the synflorescence completely fade, then the staminate flowers open on the lateral racemes of the lower parts (from the 3rd to the 5th nodes). The opening of flowers on lateral racemes occurs acropetally, and within simple umbels centripetally. D. microcarpum is a plant with a morning flowering rhythm: the opening of flowers begins early in the morning (about 5–6 a. m.) and continues until 9–10 a. m. Perfect flowers are characterized by strictly pronounced protandry. The flowering time of a perfect flower is 3–4 days, of a staminate flower – 1 day. The flowers are mainly visited by insects of two orders, Hymenoptera and Diptera. The presence of both perfect and staminate flowers, different times of their maturation and a strict synchrony of flowering of the perfect flowers of upper lateral racemes contribute to geitonogamy and also ensure cross-pollination of other individuals. Staminate flowers of lower lateral racemes or paracladia provide cross-pollination between individuals in different flowering phases.

Trioecy in <i>Ranunculus auricomus</i> (Ranunculaceae)

Trioecy is here described for the first time in the perennial herbaceous polycarpic Ranunculus auricomus L. (goldilocks buttercup) in the Moscow Region. The study has shown that R. auricomus produces three types of flowers, differing in the structure of both the androecium and gynoecium: perfect flowers (with fertile stamens and carpels), pistillate flowers (complete absence of stamens), and staminate flowers (with fertile stamens and reduced nonfunctional carpels). The perfect flowers and their parts are larger than those of the staminate and pistillate flowers. The seven studied populations included five types of plants, forming: 1) perfect flowers (76.9–80.8% of the total number of generative plants); 2) staminate flowers (2.8–3.9%); 3) pistillate flowers (1.0–3.9%); 4) perfect and staminate flowers (10.8–15.9%); 5) perfect and pistillate flowers (1.0–3.0%). Over the five years of observations (2019–2023), plants of different sexual forms did not change the sex of flowers, and the sex ratio in the populations remained stable, with minor fluctuations.

Duplicate MADS-box genes with split roles and a genetic regulatory network of floral development in long-homostyle common buckwheat

The classic ABC model postulates how three classes of floral homeotic genes (A, B and C) work in a combinational way to confer organ identity to each whorl that make up a perfect flower in core eudicot plants. Fagopyrum esculentum (Polygonaceae) produces dimorphic flowers with single whorl showy tepals, representing a considerable difference with most core eudicots flowers. Here, we explain in detail the function of a duplicated pair of floral homeotic genes involved in the formation of tepals and stamens in the LH F. esculentum. FaesAP1_1 and FaesAP1_2 work together to specify tepal identity. FaesAP3_1/2 or FaesPI_1/2 have redundant function in specifying filament identity, while FaesAP3_2 and FaesPI_2 also retain a conserved role in specifying anther development and gain novel function in style length determination. However, FaesPI_1 gain novel function in floral color formation. In addition, FaesAG can directly regulate stamen and pistil development or binds to the CArG-box of pFaesPI_1 to indirectly regulate stamen and pistil development by a gene regulatory pathway involving FaesAP1_1/2, FaesAP3_1/2 and FaesPI_1/2. Moreover, FaesAP1_1/2 can directly or indirectly regulate B-class gene (FaesAP3_1/2 and FaesPI_1/2) expression to be involved in floral development. Our work has led to detailed insights into the MADS-box gene regulatory networks that control floral developmental process in LH F. esculentum.

Androdioecy in Ranunculus ficaria ssp. ficaria (Ranunculaceae)

Androdioecy was for the first time studied in detail in the fibrous-rooted herbaceous ephemeroid polycarpic plant Ranunculus ficaria ssp. ficaria in the Moscow Region during 2019–2023. It has been established that this subspecies produces two types of flowers: perfect and staminate (remains of carpels with reduced non-functioning stigmas are preserved). Perfect flowers and their component parts are always larger than those of staminate flowers. Populations consist of three types of individuals: with perfect flowers exclusively, with perfect and staminate flowers, and with staminate flowers only. Synflorescence of R. ficaria ssp. ficaria is a closed thyrsus, the subunits of which are dichasia. In andromonoecious plants, perfect flowers are located on the top of the thyrsus axis and take a terminal position in paracladial dichasia, while staminate flowers are formed exclusively on the lateral axes of dichasia. In the five studied populations, plants with perfect flowers predominate (from 86.3 to 93.7%). Over a five-year observation period, individuals of different sexual forms did not change the sex of flowers, and the sex ratio in populations remained stable without sharp fluctuations.

Pollen morphology and reproductive biology of Calophyllum brasiliense Cambess. (Calophyllaceae)

Pollen morphology and the reproductive biology of Calophyllum brasiliense were investigated in Parque Estadual das Fontes do Ipiranga, São Paulo, Brazil. The study encompassed pollen analyses using light, scanning, and transmission electron microscopy. Additionally, we collected data on reproductive biology, main visitors/pollinators, fruit set, and seed germination. The species exhibits individuals with perfect flowers (hermaphrodites) as well as male individuals with staminate and perfect flowers. Flowering occurs in October and November, and flowers have diurnal anthesis and pollen as a floral resource. Pollen grains are monads of medium size, isopolar, oblate-spheroidal to prolate-spheroidal, 3-(4)-zonocolporate, with exine fossulate-perforate with supratectal microechini. Hermaphrodite individuals have the highest proportion of malformed pollen due to their reduced grain size. The pollen grains from the hermaphrodite individuals displayed a low viability (0.06%), while those from male individuals had higher viability (66.38% and 55.78% for perfect and staminate flowers, respectively). The stigma was receptive throughout the anthesis period. Cross-pollination between perfect flowers of male and hermaphrodite individuals resulted in 8.80% success in fruit set, but led to the development of one abnormal seedling. Cross-pollination between staminate flowers and perfect flowers of hermaphrodite individuals showed a 7.70% success rate and the control group showed an 8.00% success rate, both groups leading to the development of normal seedlings. This tree species shows relatively low reproductive success and relies on pollinators (mainly Apis mellifera, Paratrigona subnuda, Tetragonisca angustula, and Halictidae sp. 1) for the setting of fruits and seeds.

The ontogeny of flowers and inflorescences in the andromonoecious annual Iranian endemic Dicyclophora persica (Apiaceae)

Species of Apiaceae, despite uniform floral structure, show great variation in floral morphs and sexual distribution. In the present study, the ontogeny of the diclinous flowers within the cage‐shaped inflorescences of the andromonoecious Dicyclophora persica Boiss. was studied using scanning electron microscopy (SEM), to determine if they follow the same ontogenetic processes. The development of an interesting, unusual club‐like organ in the center of the umbel was also studied. Our findings show that the floral organs in diclinous flowers follow the same pattern. Petals initiate in a clockwise direction, while stamens form in a helical pattern. The perfect central sessile flower in the umbellet, despite sepal suppression, was synchronized with inner staminate flowers in the initiation of petals, stamens, and carpels. In staminate flowers, two prominent sepals initiate after the inception of the stamens. Ovules only get aborted in the late stages. The club‐like organ initiates from a naked receptacle that has no resemblances to umbellets or flowers. In perfect flowers, the delayed initiation and prolonged spatial constraints are caused by bracts and massive staminate flowers which suppress the sepals and make them sessile. Considering the ovule suppression, staminate flowers may be adapted to prevent the perfect flowers from being exposed to extreme environmental conditions.

Investigasi Miskonsepsi pada Materi Perkembangbiakan Tumbuhan Menggunakan Metode CRI (certainty of response index) di Sekolah Dasar

Science is material that is closely correlated with experiments and observations, as well as the complexity of living things and their lives, including plants. Plant reproduction is considered to be an area of material that is classified as difficult to convey because it is dense and requires long observations. This difficulty then becomes the trigger for misconceptions among students. This research aims to desCRIbe the level of misconceptions among elementary school students regarding plant reproduction material. This type of research is qualitative with a data collection method using a test instrument using the Certainty of Response Index (CRI) method, with a total of 25 questions that have been tested for validity and reliability, with a validity score of 0.468 and a reliability score of 0.60. The validity of this research was checked by testing the validity and reliability of the test instrument, checking the consistency of filling in the CRI values during the research, and using a formula to calculate the incidence of misconceptions. Based on the results of the discussion, it can be concluded that the questions can be declared valid and reliable. The research results showed that 32% had misconceptions, 28% knew the concept with certainty, 29% didn't know the concept correctly, and 4% guessed the answer. The percentage of misconceptions at 32% can be categorized as moderate. The highest misconception in the material explaining perfect flowers was 89%, while the lowest misconception in the material explaining the meaning of vegetative plant reproduction was 0%, which means that no students experienced misconceptions about the material.

Effect of Crown Layers on Reproductive Effort and Success in Andromonoecious Aesculus indica (Wall. ex Camb.) Hook (Sapindaceae) in a Temperate Forest of Garhwal Himalaya.

The andromonoecy is an unusual sex expression in trees in which an individual plant bears both functionally staminate and hermaphrodite flowers on the inflorescences. This study aims to investigate the effect of crown layers on the floral biology and reproductive effort of Aesculus indica (Wall. ex Camb.) Hook. The results revealed that the peak period of anthesis was between 06:00 and 08:00 h of the day. Male flower production was predominantly higher as compared to the perfect flowers on the inflorescences. There was no significant variation between total pollen production in staminate and perfect flowers. Features like protogyny and inter-level asynchrony promote xenogamy; however, intra-level asynchrony results in geitonogamy. Controlled pollination treatments revealed the existence of self-incompatibility in flowers. Pollination syndromes in flowers support ambophily. A trend of consistent improvement in reproductive success from lower canopy layers to upper crown layers in the analyzed trees was recorded. The crown layers have a significant impact on flower production, fruit, and seed set. An increase in male flower production due to the increment in the crown is a mechanism of reproductive assurance as a pollen donor and pollinator recipient and also due to the differential cost of expenditure of reproduction in crown layers. Andromonoecy in A. indica promotes self-incompatibility, and there was a tapering trend of reproductive success in the crown layers.

Morphological and Elemental Analysis of Cyathulaprostrata (L.) Blume using Atomic Absorption Spectroscopy

Cyathulaprostrata (L.) Blume. is a herb or under shrubs belongs to the family Amaranthaceae. It grows in loamy and sandy soils. It is commonly called small prickly chaff flower or pastures weed. It is used as a medicinal plant as well as food. The present study includes the morphological and elemental analysis of Cyathulaprostrata (L.) Blume. Cyathulaprostrata (L.) Blume consist of opposite, petiolate and entire leaves, with very small hermaphrodite flowers with bracts and bracteoles. The inflorescence is a raceme or a spike. The perianth of perfect flowers are scarious and five lobed. It has five stamens with filaments connate at the base. It has two celled anthers, obovoid and one celled ovary with a solitary ovule, simple style with capitulate stigma. The fruit is a membranous utricle enclosed in a perianth. The elemental composition of Cyathulaprostrata (L.) Blume. Leaves have been determined by using atomic absorption spectroscopy. Elements such as Ca2+, Fe2+, Mg2+, Mn2+, Na2+, Zn2+, Cd2+, Cr2+, Pb2+, Ni2+, Cu2+, Ag2+ were determined. The result of analysis showed that calcium has the highest concentration, which helps to build bones and keeps them healthy and also helps in blood clotting, muscle contraction, heart beat etc. The plant also contains other essential elements like iron, magnesium, manganese etc. The toxic metals like lead and cadmium also present in trace amount. The purpose of this study is to analyze the morphology, pharmacological potential and composition of elements in Cyathulaprostrata (L.)Blume.

Flower morphology and sexual phenotype of Capparis ovata Desf.

It was aimed to investigate the flower morphology and sexual phenotypes of Capparis ovata Desf. A C. ovata population inhabits in Çorum Osmancık Kumbaba locality. A total of 68 flower samples were collected from the population and their morphological characteristics and sexual phenotypes were investigated. According to the morphometric data, the coefficient of variation (CV) was calculated for the examined traits. Petal width (CV:3.11-20.26%) and sepal width (CV: 3.17-20.57%) showed the highest variation range. In terms of flower phenotype, 25 out of 68 flowers (36.76%) showed perfect flower and 43 (63.24%) showed male flower phenotype. The perfect flowers are hypogeynous flowers and have campylotropous type ovules. C. ovata has zygomorphic flower. C. ovata Desf. plants were defined as andromonoecious due to both the male flower and the perfect flower are present on the same plant. In conclusion, according to morphological analysis, a remarkably high variation was observed in flower morphological structures and the ratio of male flowers were found to be more common than perfect flowers in the C. ovata Desf. population. During evolutionary history, the protandry feature, in which male and female reproductive organs begin to develop at different times in perfect flowers, emerged in plants to prevent the depression of self-pollination, and inbreeding.

Gynodioecy of Origanum vulgare ssp. gracile (Lamiaceae) in Tajikistan

Gynodioecy has been identified to occur in the herbaceous polycarpic Origanum vulgare ssp. gracile growing in Tajikistan and is here described in detail for the first time. The investigated populations of O. vulgare ssp. gracile form two types of flowers, perfect and pistillate, on different individuals. In pistillate flowers, stamens are represented by staminodes. The size of many parts of the corolla and androecium of perfect flowers is significantly larger than in pistillate flowers. Four criteria have been identified that make it possible to reliably distinguish flowers of different sexual forms: the size of the corolla and its parts, the difference between calyx tube length versus corolla tube length, the position of the anthers, and the rate of development of stamens. Perfect flowers are characterized by strictly pronounced protandry. According to the pollen/ovule ratio (from 825 to 953), O. vulgare ssp. gracile is facultatively xenogamous. Hermaphrodites predominated (from 58.9 to 76.2%) in five of the investigated populations. The frequency of females in O. vulgare ssp. gracile was shown to be most dependent on annual precipitation. Finally, we discuss the presence and distribution of gynodioecy within the genus Origanum and its adaptive significance for the existence of populations of O. vulgare ssp. gracile.

Recent Advances in Natural Deastringency and Genetic Improvement of Chinese PCNA Persimmon (Diospyros kaki)

Persimmon (Diospyros kaki) is a worldwide fruit cultivated mainly in the East Asia, Mediterranean, Caucasus, Latin America, and Oceania regions. This fruit contains abundant proanthocyanidins (PAs, also called condensed tannins), whose biosynthesis is the main cause of fruit astringency. As the original centre and top producing country, China has discovered a unique type with desirable natural deastringency, the Chinese pollination-constant non-astringent (C-PCNA) persimmon. Studies have revealed that the C-PCNA trait is controlled by a single and dominant locus, which differs from that of another type, the Japanese PCNA type, with recessive loci. In the C-PCNA type, accumulating evidence has shown that the astringency removal process involves two pathways (“dilution effect” and “coagulation effect”). Moreover, molecular marker-assisted selection (MAS) for the natural deastringency trait locus in C-PCNA has been used to test the non-astringency/astringency trait of hybrid offspring at the seedling stage. Importantly, persimmon can bear male flowers, female flowers, and perfect flowers, but sex-linked MAS has been developed for female-only persimmon. This sex-linked MAS, together with astringency-linked MAS and embryo rescue technology, may even shorten the conventional cross-breeding period of about 2–3 years. In addition, recently studies have established a stable genetic transformation system for persimmon transgenic improvement. Despite these efforts, how synthetic PAs and metabolism pathways lead to a deastringent trait remains unclear for persimmon. Thus, our review summarizes the latest research progress on the natural deastringency mechanism in C-PCNA, and we provide a new viewpoint for the genetic improvement of persimmon breeding in China.

Agro-climatic requirements and reproductive potentials of pistachio pollinator specimens grown in warm area in North Africa

The success of pistachio production depends on the best selection of female and male trees combined with perfect flowering synchronization. In warm areas, flowering is highly affected by climate change and selecting an appropriate pollinator for a female cultivar is challenging. In this study, seventeen local pistachio pollinators were under study in the arid Central Tunisian region. Bloom timing and chilling and heat requirements were determined based on 17 years of phenology records and using the Partial Least Squares (PLS) regression. Pollen production and quality were assessed. Three pollinator groups as early-, intermediate- and late-flowering ones were delineated and their median bloom dates spanned from DOY84 to DOY110, with bloom dates spread over 27 and 37 days, allowing perfect coverage of the bloom period of the female cultivar Mateur. Within the three groups, the most interesting candidates were H23a and H26a as intermediate-flowering males, H3a, H3b, H18, H23b and H26b as late-flowering ones and H30 as an early-flowering male covering the first flowers blooming. The pollen viability was high in all the studied pollinators (92–98 %). However, great differences existed in inflorescence density (in the range of 2–4) and pollen production per inflorescence (in the range of 191–424 mg). Based on flowering synchronization, the suitable ones had less variable chilling requirements in the range of 33–37 Chill Portions (CP) in warm areas against a significant variability of the heat needs (8783–17,302 GDH). This supported the key role of increased heat accumulation to compensate for the lack of chill and when chilling requirements are not fully fulfilled in warm areas until the chill threshold value of 25 CP. A significant delayed flowering period occurred for all pistachio pollinators when chill accumulation dropped below 25 CP, which may cause asynchronous flowering, leading to poor pollination. In conclusion, bloom timing and pollen production are common variables to characterize pistachio pollinators. The agroclimatic needs could be a relevant tool for planning the best combination linked to local conditions, while estimation improvement is required for warm areas. However, pistachio cultivation in warmer areas will be viable until a certain chill level. Pistachio cultivars will be able to grow, while lack of chill will be overcome with heat accumulation key role for chill compensation until a threshold of 25CP. These findings are of high interest for the warmest orchards, which will cover many important fruit-growing regions with Mediterranean climates all over the world with the expected climate change.

Breeding system in Olea ferruginea Royle (Oleaceae): comparative performance of staminate and perfect flowers in reproductive assurance

ABSTRACT Olea ferruginea, a wild widely distributed species of the olive lineage, exhibits andromonoecy with protogynous perfect (hermaphrodite) and staminate (male) flowers. The present communication elucidates the differential performance of staminate and perfect flowers in reproductive assurance. The flowering chronology and function of perfect and staminate flowers in the breeding system were investigated to understand the breeding behavior of the species. In terms of breeding behavior, pollen from staminate and perfect flowers was used to establish their role in breeding system under different pollination treatments. Results indicate higher pollen viability, germination, and pollen tube growth of staminate than perfect flowers. Results from pollen counts and morphological investigations show slight differences in both types. The species is self-incompatible which is indicated by pollen germination, the average number of pollen tubes in the style, and the fruit set following self and cross-pollination. Hand cross-pollination improves natural fruit set, especially when pollen from staminate flowers was used. Although the relict role of attracting pollinators cannot be fully discarded, it is suggested that the main benefit supplied by the formation of staminate flowers in olives is to promote male fitness by raising pollen output at the population level.

ANDROMONOECY IN <i>GALIUM ODORATUM</i> (RUBIACEAE)

The manifestation of sexual polymorphism in the sweet woodruff Galium odoratum was studied in the Moscow region during 2021–2023. The plant is a common perennial herbaceous, long-rhizome, polycarpic sciophyte. We find that at low illumination (less than 15% of total sunlight) only perfect flowers are formed. With increasing illumination (to up to 60% of full sunlight in clear weather), both perfect and staminate flowers are formed on individual plants. The perfect flowers of G. odoratum are complete, actinomorphic, tetracyclic, and heteromeric. In contrast, in staminate flowers the gynoecium is reduced, but its rudiments are preserved in the form of sterile stigmas and very short stylodia. Perfect flowers are significantly larger than staminate ones. The inflorescence in G. odoratum is a panicle-shaped monotelic, heterocladial, conjunctive thyrsus. Staminate flowers in andromonoecious individuals are located only on shoots of order IV, and their proportion varies from 12% to 30%. We finally discuss the possible reasons for the manifestation of andromonoecy in flowering plants under the influence of various environmental factors.

Study of Morphological Qualitative and Quantitative Characterization of Different Traits in Tomato (Solanum lycopersicum L.) Genotypes

Tomato is classified as a warm-season crop and is characterized by two distinct plant growth habits: determinate and indeterminate. The flowers of tomatoes are typically bisexual and possess both male and female reproductive structures, making them perfect flowers. The stigma of the flower is surrounded by a protective anther cone, which promotes self-pollination. This self-pollination trait in tomato plants facilitates their maintenance breeding, and simple selection methods can be employed to effectively improve the crop. The current investigation involved the characterization of twenty-five tomato germplasm genotypes. The experimental was carried out during rabi season 2021-2022 and 2022-2023 at Horticulture Research Centre, College of Horticulture, Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut. Seedlings of tomato were transplanted at spacing of 60 x 45 cm in randomized block design with three replications. Data was collected based on eight qualitative traits, namely, plant growth habit, leaf colour, flower colour, fruit size, fruit shape, fruit colour, fruit surface, and stem end fruit shape. The tomato genotypes demonstrated significant variability in all qualitative traits, with the exception of the fruit surface trait. This highlights the importance of focusing on these traits in future crop improvement programs for tomato.

Screening of Early Flowering Lotus (Nelumbo nucifera Gaertn.) Cultivars and Effects of Different Cultivars on Flowering Period.

Flowering time is an important trait that determines the breeding process of ornamental plants. The flowering period of lotus (Nelumbo nucifera Gaertn.) is mainly concentrated in June-August. During this period, the weather is hot and there are few tourists, which made many lotus scenic spots difficult to operate. People have a strong demand for early flowering lotus cultivars. In this paper, 30 lotus cultivars with high ornamental value were selected as materials and their phenological periods were observed for two consecutive years in 2019 and 2020. A number of cultivars with early flowering potential and stable flowering periods, such as 'Fenyanzi', 'Chengshanqiuyue', 'Xianghumingyue' and 'Wuzhilian', were screened by K-Means clustering method. The relationship between accumulated temperature and flowering time of 19 lotus cultivars at different growth stages was analyzed. It was found that lotus cultivars with early flowering traits could adapt well to the changes of early environmental temperature and were not affected by low temperature. On the other hand, by analyzing the relationship between different traits and flowering time of three typical cultivars, such as rhizome weight, phenological period, etc., it shows that the nutrient content of the rhizome and the early morphology of plants will affect the flowering time. These results provide a reference for the formation of a systematic lotus early flowering cultivar breeding mechanism and the establishment of a perfect flowering regulation technology system, which can further improve the ornamental value of lotus and promote industrial development.

Study of Flowering Phenology of West Sumatera Local Jamblang (Syzygium cumini (L.) Skeels)

The flower of the jamblang plant (Syzygium cumini (L.) Skeels) is a type of compound flower. The jamblang flowers have a panicle like shape with branches that are far apart. The phenology study has practical importance for planning the plant breeding program, including if there will be the development of superior jamblang varieties. The purpose of this study was to determine the development and biological characteristics of jamblang flowers. The observation was conducted on the duration of the flower initiation phase, the small bud phase, the large bud phase, and the complete blooming phase (anthesis), and also flower biological characteristics. This research was carried out in Padang City from February to May 2022 using a survey method with purposive sampling. There are three of plant genotypes that were used as object in this study. The development of jamblang flowers in each phase has a different time for each flower genotype. The characteristics of flowers have similarities in each of their genotypes. Jamblang plant is classified as plants that have a complete flower structure and a perfect flower because it has two penitals on one flower.

SEXUAL POLYMORPHISM OF <i>RANUNCULUS CASSUBICUS</i> (RANUNCULACEAE) IN MOSCOW REGION

For the first time, gynodioecy is described in a perennial herbaceous polycarpic plant Ranunculus cassubicus L. (Kashubian buttercup) in the Moscow Region. It was revealed that R. cassubicus forms three types of flowers differing in the androecium structure: perfect (with fertile stamens and carpels), partially male-sterile (the number of stamens varies greatly and is much less than in perfect flowers), and pistillate ones (stamens completely missing). The sizes of flowers and their parts decrease in many studied parameters in the following row: perfect – partially male-sterile – pistillate. The studied 12 populations included six types of individuals forming: 1) only perfect flowers (83.1–89.2% of the total number of generative plants); 2) perfect and partially male-sterile flowers (4.0–6.5%); 3) only partially male-sterile flowers (2.8–3.9%); 4) perfect and pistillate flowers (1.4–2.6%); 5) pistillate and partially male-sterile flowers (1.2–2.9%); 6) only pistillate flowers (0.6–1.5%). It is established that over three years of observations (2020–2022), individuals of different sexual forms did not change the sex of flowers, and the sexual structure of populations remained stable, without sharp fluctuations.

GYNODIOECY IN <i>NEPETA GONTSCHAROVII</i> (LAMIACEAE)

Gynodioecy is described for the first time in Nepeta gontscharovii, an endemic herbaceous polycarpic plant from the Hissar Darvaz mountains (Tajikistan). N. gontscharovii forms the flowers of two types: perfect and pistillate, on different plants. Both types of flowers are median zygomorphic, tetracyclic, and heteromeric: pentameric in the perianth, tetrameric in the androecium, and dimeric in the gynoecium. The stamens in pistillate flowers have transformed into staminodes. We have observed that the values of the vast majority of the studied morphological traits in perfect flowers are larger than in the pistillate ones. Three criteria have been identified which allow to distinguish reliably the flowers of different sexual forms: the size of flowers and their parts, the ratio of the length of corolla tube and calyx, and the position of anthers. The perfect flowers are characterized by pronounced protandry. According to the determined pollen/ovules ratio (from 1286 to 1657), N. gontscharovii is to be considered as a facultative xenogamous species. Females were rare (6.6%) in the studied population. We discuss the presence and distribution of gynodioecy within the genus Nepeta and section Macronepeta and its adaptive significance for the N. gontscharovii population.