Single Flower Research Articles

The MADS-box gene PpPI is a key regulator of the double-flower trait in peach.

Double flower is an invaluable trait in ornamental peach, but the mechanism underlying its development remains largely unknown. Here, we report the roles of ABCE model genes in double flower development in peach. A total of nine ABCE regulatory genes, including eight MADS-box genes and one AP2/EREBP gene, were identified in the peach genome. Subcellular localization assay showed that all the ABCE proteins were localized in the nucleus. Four genes, PpAP1, PpAP3, PpSEP3, and PpPI, showed a difference in expression levels between single and double flowers. Ectopic overexpression of PpPI increased petal number in Arabidopsis, while transgenic lines overexpressing PpAP3 or PpSEP3 were morphologically similar to wild-type. Ectopic overexpression of PpAP1 resulted in a significant decrease in the number of basal leaves and caused early flowering. These results suggest that PpPI is likely crucial for double flower development in peach. In addition, double flowers have petaloid sepals and stamens, and single flower could occasionally change to be double flower by converting stamens to petals in peach, suggesting that the double-flower trait is likely to have evolved from an ancestral single-flower structure. Our results provide new insights into mechanisms underlying the double-flower trait in peach.

Effect of grafting on the growth and flowering of sprays chrysanthemums

To study the effect of grafting on the growth and flowering of spray chrysanthemum, Artemisia annua was used as the rootstock and eight spray chrysanthemum varieties 'Zhongshan Jinyang' ('ZSJY'), 'Zhongshan Xinmolian' ('ZSXML'), 'Zhongshan Xuerong' ('ZSXR'), 'Zhongshan Yinggui' ('ZSYG'), 'Zhongshan Zaohong' ('ZSZH'), 'Zhongshan Zhiying' ('ZSZY'), 'Zhongshan Zisongguo' ('ZSZSG'), and 'Zhongshan Ziwei' ('ZSZW') were used as the scions. The plant survival ratio, growth index (crown width, crown circumference, and biomass), and flowering characteristics (total inflorescences per plant, flower diameter, fresh and dry weight of single flowers, and flowering period) were studied after grafting. We found that for variety ‘ZSYG’, the grafted plants showed a 58.4% increase in crown width, a 68.7% increase in crown circumference, a 61.8% increase in the dry weight of the scion, a 108.4% increase in the dry weight of root, a 72.3% increase in the total dry weight, a 28.3% increase in root/shoot, and a 135.2% increase in the total inflorescences per plant compared to those in the own-rooted plants. Grafting can not only promote plant growth and increase plant biomass, and the total inflorescences per plant of spray chrysanthemum but also lengthen the ornamental period of spray chrysanthemum by advancing flowering and delaying the final flowering period. The budding period can be advanced by 13 d, the final flowering period can be delayed by 4 d, and the ornamental period can be increased by 10 d. Therefore, grafting facilitates the growth of spray chrysanthemums, advances flowering, and prolongs the ornamental period.

Tropidogyne euthystyla sp. nov., a new small-flowered addition to the genus from mid-Cretaceous Myanmar amber

Tropidogyne euthystyla, described here, is the fourth species of this fossil genus to have been reported from amber deposits in northern Myanmar. The species are alike in features of the calyx, the shape and venation of the inferior ovary, and the absence of petals. They differ in the number and form of the styles, the lobing of the epigynous disc, and whether the flowers are apparently bisexual or unisexual. In the one species for which several flowers are available for study, T. pentaptera, floral diameters vary from 3.5 to 5.0 mm. The present species, known only from a single flower, is the smallest in the genus, with a floral diameter of only 2 mm. It differs from the 3 previously described species in having 2 stout, erect styles bearing a terminal stigma, whereas the other species have 2 or 3 short or long, arching styles that are decurrently stigmatic along the adaxial surface.

Short Communication: Analysis of the chromosome numbers of Zinnia elegans Jacq. in single, double, and pom-pom flowers

Abstract. Saifudin, Shafira S, Dwiranti A, Salamah A. 2021. Short Communication: Analysis of the chromosome numbers of Zinnia elegans Jacq. in single, double, and pom-pom flowers. Biodiversitas 22: 2771-2777. Zinnia elegans Jacq. is highly valued as an ornamental plant with a variety of flower colors, sizes, and shapes. Polyploidization has been reported in Z. elegans with pom-pom flowers, nevertheless, the variation in chromosome numbers of various flower shapes has yet to be investigated. This study aimed to analyze the chromosome numbers of Z. elegans Jacq. cultivar “California Giant,” “Lilliput,” and “Cactus Flowered Mix” with single, double, and pom-pom flowers to determine their variations and identify the morphology of the flowers. Chromosomes were prepared using the squashing method, and images were analyzed using the Chromosome Image Analyzing System (CHIAS) IV. The minimum of 5 slides was prepared for each flower type from each cultivar. The results show that the three cultivars are diploid plants (2n = 24) with varying flower morphology. The single and double flowers of Z. elegans “Lilliput” and the single flower of “Cactus Flowered Mix” showed no variation in chromosome numbers. In contrast, chromosome number variation was found in the pom-pom flower of Z. elegans “California Giant” (2n = 22, 24, 48) and the double flower of “Cactus Flowered Mix” (2n = 9, 13, 15, 24). Two cultivars, Z. elegans “California Giant” and Z. elegans “Cactus Flowered Mix,” were successfully analyzed using CHIAS IV. Statistical analysis using a t-test (? = 0.05) showed that the total chromosome length of Z. elegans “California Giant” (2n = 24) was significantly greater than that of Z. elegans “Cactus Flowered Mix” (2n = 24). Chromosome satellites were found in both cultivars.

Artabotrys pachypetalus (Annonaceae), a new species from China.

Artabotrys pachypetalussp. nov. is described from Guangdong, Guangxi, Guizhou, Hunan and Jiangxi in China. A detailed description, distribution data, along with a color plate and a line drawing are provided. In China, specimens representing this species were formerly misidentified as A. multiflorus or A. hongkongensis (= A. blumei). Artabotrys blumei typically has a single flower per inflorescence, whereas both Artabotrys pachypetalus and A. multiflorus have multiple flowers per inflorescence. In addition, A. pachypetalus is readily distinguished from A. multiflorus in having thicker and shorter petals, and connivent and somewhat trigonal or terete inner petal blades. Artabotrys pachypetalus is most similar to A. punctulatus because both have multi-flowered inflorescences and similar petal length, but A. pachypetalus differs in having cream petals in vivo, connivent inner petal blades, and a short, raised rim above the inner petal claw. Artabotrys multiflorus should be excluded from the flora of China because none of the Chinese specimens of Artabotrys collected so far fall within the variation of A. multiflorus.

Flowering characteristics and reproductive biology of Nymphaea hybrid, a precious water lily

Nymphaea hybrid is a precious aquatic plant of the family Nymphaeaceae that has esthetic, economic, medicinal, and ecological values. Owing to its spectrum of color, especially that of the rare blue strain of the genus Nymphaea, it has gained importance in the breeding of water lilies. However, the lack of research on its flowering characteristics and reproductive biology has severely hindered the reproduction and breeding of superior water lily varieties. In this study, the flowering phenology, floral characteristics, and flower-visiting insects of N. hybrid were assessed. The microstructures of stigmata and pollen grains were observed and the stigma receptivity was determined. Pollen viability was measured by an in vitro germination experiment. We also evaluated the breeding system by measuring the pollen/ovule (P/O) ratio, determining the outcrossing index (OCI), and performing field pollination experiments. The N. hybrid population flowered from late May to mid-November, with a flowering period of approximately 160 days. The florescence of a single flower ranged for 3‒5 days from June‒August and for 5‒10 days from September‒November. Inverse herkogamy and protogyny were exhibited by N. hybrid flowers. Stigmata were wet with papillae distributed on their surface, and the pollen grains were oblate with granular ornamentation of different sizes on their surface. The pollen germination rate was highest when they were deposited in a medium containing 5% sucrose, 0.001% boric acid, 1% agar, and 20 mg/L calcium chloride and cultured at 30 °C. Stigma receptivity was the strongest on the 1st day of floral anthesis, and pollen viability was the highest between 9:30 a.m. and 11:30 a.m. on the 2nd day of floral anthesis. The P/O ratio suggests that xenogamy is the main reproductive system. Artificial pollination results indicated that N. hybrid favored outcrossing and required the participation of pollinators, such as Bombus lucorum L. and Xylocopa s.str. valga Gerstaecker, both of which are effective bee pollinators. These results can aid in formulation and implementation of strategies for N. hybrid hybridization programs, and can also improve the controlled pollination efficiency for agronomic and ornamental purposes.

Generalization of Foraging Experience Biases Bees Toward Flowers With Complex Morphologies

The importance of pollinators as selective agents for many floral traits is well established, but understanding their role in the evolution of complex floral shapes remains challenging. This is because pollinators often need much practice to efficiently handle morphologically complex flowers and extract their food rewards. What induces foragers to persistently visit and pollinate complex flowers despite their initial low profitability? We previously found that naive bumblebees, and unsuccessful feeding attempts of experienced ones, contribute to the pollination of complex flowers. Here we tested a complementary hypothesis, positing that successful foraging on flowers of one complex shape prepares pollinators to visit other species of different complex morphologies. We trained bumblebees to computer-controlled artificial flowers that were either simple, complex or both simple and complex. We then recorded their feeding choices and handling times on a second array of simple and complex flowers that had different shapes and required another handling technique. Bees trained on a single flower type (whether simple or complex) preferred flowers of the same type in the testing array. The foragers’ preferences after training on both flower types depended on the reward schedule during training: when both flower types rewarded equally, simple flowers were preferred at the test phase; when complex flowers provided higher reward during training, they became the preferred flower type during testing. These results suggest that successful foraging on complex flowers, especially when highly rewarding, can indeed induce insect pollinators to attempt additional flower species with other complex shapes.

Reproductive effort of Caragana microphylla under long‐term grazing exclusion in a semi‐arid grassland

AbstractGrazing exclusion is a commonly used method to protect and recover herbaceous plants in grasslands, and woody expansion is a common phenomenon in grasslands. However, the effects of grazing exclusion on shrub reproduction remain poorly understood. We investigated the effects of long‐term grazing exclusion (0, 8, 30 and 34 years) on reproductive effort of Caragana microphylla in the semi‐arid Inner Mongolia Steppe. Our results showed that the 8‐year grazing exclusion significantly increased the number of flowers, juvenile pods, mature pods and seed (seed number increased 33.5%) of C. microphylla, however, the 30‐ to 34‐year grazing exclusion significantly decreased seed production (seed number decreased 77.9% and 88.1%) of C. microphylla. The 8‐year grazing exclusion had no significant effect on the single flower weight, while the 30‐ to 34‐year grazing exclusion significantly decreased (31.7% and 38.7%) the single flower weight. The grazing exclusion had no significant effect on the seed number per pod. The 8‐year grazing exclusion significantly increased sexual allocation (31.6%), and it had no significant effect on sexual allocation efficiency; however, the 30‐ to 34‐year grazing exclusion significantly decreased the sexual allocation (50.4% and 70.4%) and sexual allocation efficiency (55.5% and 60.1%). The 8‐year grazing exclusion significantly increased seed weight and seed vigor (seed weight increased 18.7%, seed vigor index increased 28.7%), whereas the 30‐ to 34‐year grazing exclusion decreased these indexes (seed weight decreased 14.2% and 21.0%, seed vigor index decreased 9.1% and 14.7%). These results indicated that the 8‐year grazing exclusion increased reproductive effort of C. microphylla, while the 30‐ to 34‐year grazing exclusion sharply decreased the reproductive effort of this shrub species. Our study suggests long‐term grazing exclusion limited the expansion of shrubs in grassland by decreasing sexual reproduction and thus inhibiting population growth of shrubs.

Mechanism of Leaf Vein Coloration and Inheritance of Leaf Vein Color, Flower Form, and Floral Symmetry in Gloxinia

Double-flowered gloxinia (Sinningia speciosa) cultivars with foliar variegation might have a greater market appeal as flowering foliage plants. Crosses were made among 16 gloxinia cultivars and their progenies were analyzed to determine the inheritance of leaf vein color, flower form, and floral symmetry. All plants from self-pollinating white-veined cultivars or crosses between white-veined and green-veined cultivars produced white veins. Progeny derived from self-pollinating plants of white-veined cultivars × green-veined cultivars segregated into a ratio of 3 white-veined:1 green-veined. All plants from self-pollinating or cross-pollinating single-flowered cultivars produced single flowers. Progeny of self-pollination or crosses between double-flowered cultivars segregated into a ratio of 3 double flowers:1 single flower. Contingency chi-square tests revealed that leaf vein color and flower form were inherited independently. New gloxinia progenies with homozygous white veins and double flowers were successfully developed from the F2 segregating population. Plants from self-pollinating or cross-pollinating cultivars with actinomorphic flowers produced actinomorphic flowers. A single dominant gene expressed in the homozygous or heterozygous state resulted in the zygomorphic flowers. Independent inheritance was observed between vein color and floral symmetry. Air spaces between the epidermis and the mesophyll cells were observed in the white, but not in the green, leaf vein portions. Net photosynthesis did not differ significantly between the white vein and adjacent green portion of the same leaf.

Differences in Pollination Efficiency Among Three Bee Species in a Greenhouse and Their Effects on Yield and Fruit Quality of Northern Highbush ‘Bluecrop’ Blueberry

Different pollinators exhibit different adaptability to plants. Here, we compared the performance in visiting frequency and pollination efficiency among three bee pollinators (Bombus terrestris, Apis cerana, and Apis mellifera) on greenhouse-grown northern highbush ‘Bluecrop’ blueberry plants and evaluate their effects on yield and fruit quality. Our results indicated that the duration of daily flower-visiting of B. terrestris was 24 and 64 minutes longer than that of A. cerana and A. mellifera, respectively, and the visiting time of a single flower for B. terrestris was substantially shorter than the other two bee species, and pollen deposition on the stigma from single visit by B. terrestris was twice and three times that of A. cerana and A. mellifera, respectively. The yield of individual plants pollinated by B. terrestris showed an increase of 11.4% and 20.0% compared with the plants pollinated by A. cerana and A. mellifera, respectively, with the rate of Grade I fruit (>18 mm diameter) reaching 50.8%, compared with 32.9% and 22.5% for A. cerana and A. mellifera groups, respectively. Moreover, the early-to-midseason yield of plants pollinated by B. terrestris was higher, and the ripening time was 3 to 4 days earlier. An artificial pollination experiment demonstrated that seed set of high (≈300), medium (90–110), and low (20–30) pollination amounts were 43.0%, 42.5%, and 10.5%, respectively, and the corresponding mean weights of single fruits (related to the seed number inside) were 2.8, 2.7, and 1.2 g, respectively. The highly efficient pollination of B. terrestris was attributed to its behavior of buzz-pollination. Therefore, it is preferential for pollination of ‘Bluecrop’ blueberry in the greenhouse.

RESPONSE OF PLANT GROWTH REGULATORS ON THE GROWTH, FLOWERING AND YIELD ATTRIBUTES OF AFRICAN MARIGOLD (TAGETES ERECTA. L)

Tagetes is a genus of annual, perennial or herbaceous plant in the family Asteraceae. Most of the species have pinnate green leaves. Blooms are naturally occurring in golden, orangeyellow, and white colour, often with maroon highlights. Floral heads are 4 to 6 cm in diameter, generally with both ray florets and disc florets. The present study was conducted at the post graduate research laboratory at Department of Horticulture, Faculty of Agriculture, Annamalai University to find out the “Effect of plant growth regulators on flowering and yield of African marigold (Tagetes erecta Linn)”. The experiment was laid out in Randomized Block Design with three replications. There were ten treatments, viz., GA3 100 ppm, GA3 200 ppm and GA3 300 ppm, NAA 100 ppm, NAA 200 ppm, NAA 300 ppm, Ethrel 50 ppm, Ethrel 100 ppm, and Ethrel 150 ppm and control. Among the growth regulators tried, GA3 200 ppm as foliar application on 30 and 60 days after transplanting registered the highest values for plant characters like plant height (47.1 cm), number of branches ( 35.1), days taken to first flower bud appearance (39.3 days), days taken to flower opening (37.6 days), longevity of flower (11.17 days), stalk length (12.1 cm), diameter of flower (7.8 cm), number of flowers per plant (40.3), weight of the single flower (9.1 g), yield of flowers per plant (337 g) and flower yield per plot (11.1 kg). From the present study, it is recommended that spraying of GA3 200 ppm on 30 and 60 days after transplanting improved yield and quality of African marigold flowers.

Use of Direct Perception in Understanding The Lost Secret Language of Plants

Every single plant, tree, herbs and flowers symbolize emotions, ideas and actions. Every plant in nature signifies the things that you want or value in your life. These have a capacity to create a positive environment and spread happiness all over. Understanding the symbolism of plants helps in picking the right gifts that give a meaning to life. Picking the plants and flowers for the biggest moments of life is like a true symbol adding to the life’s purpose. One can learn to speak the language of plants. They have their own individual and unique energy which can be used for medicinal purpose. When a particular plant or flower is selected, its different colors have their own meanings. It helps to develop a connection with the natural world and to bring back the lives into balance. Each human being has a special relationship to the plants.

The Dioecious Adenia natalensis W.J.de Wilde (Passifloraceae): Discovery and Description of the Female

Adenia natalensis W.J.de Wilde, rediscovered recently in the lower Thukela River Valley in central KwaZulu-Natal, South Africa has now been identified from the Mngeni River system to the south, from three additional sites. A single flowering and fruiting female plant has been observed at Botha's Hill near Durban, allowing for a complete description of this dioecious species.

Morpho-physiological features of Stephanotis floribunda inconditions of greenhouse culture

Stephanotis floribunda Brongn. is an ornamental pot-plant characterized with intensive growth, profuse flowering, stability in interior conditions. We studied the growth and developmental rhythm of the shoot system of the experimental plant, investigated its biomorphological features, compared the physiological and biochemical characteristics of the assimilating organs of Stephanotis floribunda during the growing season in phases: budding, mass flowering, flowering end, single flowering, slow growth and relative peace. The system of stephanotis shoots is characterized by a plagiotropic growth direction and all its vegetative-generative areas are structurally homogeneous. Due to its ability to take root in each node, the structural unit – metamer – retains autonomy and is able to restore the entire individual. The indicators of the pigment composition throughout the whole observation period indicate the stability of the photosynthetic system, and confirm the significant adaptation potential of Stephanotis floribunda in protected ground conditions.

Investigation on reproductive characteristics of Polygonatum cyrtonema

The study is aimed to investigate the reproductive biology characteristics of Polygonatum cyrtonema, especially including phenology, flower bud differentiation, flowering timing, floral traits, pollen vigor and stigma receptivity. The results showed that P. cyrtonema forms inflorescence before the leaves spread. In the wild, P. cyrtonema is mainly pollinated by insects such as bumblebees, with a seed setting rate of 65.12%. The seed setting rate of indoor single plant isolation or self-pollination enclosed by parchment paper bag is 0, indicating that it is self-incompatible. In Lin'an city, seedlings begin to emerge from mid-March to early April(the temperature is higher than 7.5 ℃), buds begin to emerge from the end of March to mid-April, and then undergo the full bloom stage from mid-to-late April, and the final flowering stage from the end of April to mid-May. The whole flowering period lasts 36 to 45 days. There are obvious differences in the phenology of different provenances. The flowers come into bloom from the base to the top along the aboveground main axis, which usually contain 4-22 inflorescences with(2-) 4-10(-21) flowers per inflorescence. The flowering pe-riod for a single plant is 26-38 days. The single flower lasts about 20-25 days from budding to opening and withers 2 days after pollination, and then the ovary will gradually expand. If unpollinated, it will continue to bloom for 3-5 days and then wither. Flower development period is significantly related to pollen vigor and stigma remittance. The pollen viability is the highest when the flower is fully opened with anthers gathering on the stigma, and the receptivity is the strongest when the stigma protrudes out of the perianth and secretes mucus. The fruits and seeds ripen in October, and proper shading can ensure the smooth development and maturity of the seeds. This study provides a basis for the hybrid breeding and seed production of P. cyrtonema.

Response of plant growth regulators and multi micronutrient on growth, yield and quality of chrysanthemum cv. Ratlam selection

The present experiment entitled “Interaction Response of Plant growth regulators and Multi micronutrient on Growth, Yield and Quality of Chrysanthemum cv. Ratlam Selection” was carried out at Jamuvadi Farm, Department of Horticulture, College of Agriculture, Junagadh Agricultural University, Junagadh, during October 2018 to February 2019 and October 2019 to February 2020. The experiment was laid out in Randomized Block Design with Factorial concept (FRBD) consisting two factors with three replications. The treatment comprised with five plant growth regulators and three treatments of multi micronutrient. The results indicated that the foliar application of GA3 @ 150 ppm with multi micronutrient (grade-IV) @ 0.75% foliar spray at 30 & 45 DAT after transplanting in addition to recommended dose of fertilizers (120: 60: 60 kg/ha NPK) produced better growth and yield characters viz., plant height, plant spread, number of branches, stem thickness, number of flowers per plant, number of flowers per plot, weight of single flower, flower yield per plot and flower yield per hectare as well as quality characters viz., vase life of cut flowers, shelf life of loose flowers, in situ longevity of flowers, flower stalk length and flower diameter in chrysanthemum cv. Ratlam Selection.

Global transcriptional profiling between inbred parents and hybrids provides comprehensive insights into ear-length heterosis of maize (Zea mays)

BackgroundMaize (Zea mays) ear length, which is an important yield component, exhibits strong heterosis. Understanding the potential molecular mechanisms of ear-length heterosis is critical for efficient yield-related breeding.ResultsHere, a joint netted pattern, including six parent-hybrid triplets, was designed on the basis of two maize lines harboring long (T121 line) and short (T126 line) ears. Global transcriptional profiling of young ears (containing meristem) was performed. Multiple comparative analyses revealed that 874 differentially expressed genes are mainly responsible for the ear-length variation between T121 and T126 lines. Among them, four key genes, Zm00001d049958, Zm00001d027359, Zm00001d048502 and Zm00001d052138, were identified as being related to meristem development, which corroborated their roles in the superior additive genetic effects on ear length in T121 line. Non-additive expression patterns were used to identify candidate genes related to ear-length heterosis. A non-additively expressed gene (Zm00001d050649) was associated with the timing of meristematic phase transition and was determined to be the homolog of tomato SELF PRUNING, which assists SINGLE FLOWER TRUSS in driving yield-related heterosis, indicating that Zm00001d050649 is a potential contributor to drive heterotic effect on ear length.ConclusionOur results suggest that inbred parents provide genetic and heterotic effects on the ear lengths of their corresponding F1 hybrids through two independent pathways. These findings provide comprehensive insights into the transcriptional regulation of ear length and improve the understanding of ear-length heterosis in maize.

Characterization of the FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 Homolog SlFKF1 in Tomato as a Model for Plants with Fleshy Fruit.

FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 (FKF1) is a blue-light receptor whose function is related to flowering promotion under long-day conditions in Arabidopsis thaliana. However, information about the physiological role of FKF1 in day-neutral plants and even the physiological role other than photoperiodic flowering is lacking. Thus, the FKF1 homolog SlFKF1 was investigated in tomato, a day-neutral plant and a useful model for plants with fleshy fruit. It was confirmed that SlFKF1 belongs to the FKF1 group by phylogenetic tree analysis. The high sequence identity with A. thaliana FKF1, the conserved amino acids essential for function, and the similarity in the diurnal change in expression suggested that SlFKF1 may have similar functions to A. thaliana FKF1. CONSTANS (CO) is a transcription factor regulated by FKF1 and is responsible for the transcription of genes downstream of CO. cis-Regulatory elements targeted by CO were found in the promoter region of SINGLE FLOWER TRUSS (SFT) and RIN, which are involved in the regulation of flowering and fruit ripening, respectively. The blue-light effects on SlFKF1 expression, flowering, and fruit lycopene concentration have been observed in this study and previous studies. It was confirmed in RNA interference lines that the low expression of SlFKF1 is associated with late flowering with increased leaflets and low lycopene concentrations. This study sheds light on the various physiological roles of FKF1 in plants.

Phenology of Pentaphylloides representatives in the Mari El Republic

Representatives of the genus Pentaphylloides are low ornamental shrubs that are valued for long abundant flowering, compact size and unpretentiousness to growing conditions. P. fruticosa is a valuable plant that has not only decorative value, but also food, medicinal, soil protection. For medicinal purposes, young flowering shoots are used, harvested during budding and flowering. The article presents the results of phenological observations in 2018-2020. The objects of the study were plants of 8 kinds of Pentaphylloides in the collection of the Botanical Garden-Institute of Volga State University of Technology (Yoshkar-Ola, Mari El Republic). The studied plants undergo most phases of seasonal development, with the exception of the mass end of shoot growth, complete lignification of shoots, mass ripening of fruits, mass leaf fall. Species and cultivars vegetated from the end of April – the beginning of May to the end of October in a short time. The vegetation period was 177-182 days. There was no significant difference in the timing of the passage of phenophases between the taxa. Plants of Р. × friedrichsenii and P. mandschurica passed most of the phenophases earlier than the average dates for the genus, and 'Goldfinger' and 'Klondike' – later. The earliest and longest flowering was characterized by P. friedrichsenii (65 d.), the latest and shortest – P. fruticosa (28 d.). All plants of P. fruticosa cultivars bloomed for a longer period than the species. After mass flowering, single flowers were observed in representatives of Pentaphyloides until mid-October.

Comparison of two criteria on the essential number calculation of Andrena camellia.

Andrena camellia Wu is one of the primary pollinators of Camellia oleifera A. in China. In this paper, the essential number of individuals for efficient pollination by this species was calculated via two criteria, based on various indicators including counts of pollen grains in provisions, from single visits, and from single foraging trips overall; single flower visit duration; single flight period duration; number of eggs laid by a single female over their lifetime; and the average number of flowers per plant. Based on the number of pollen grains collected per flower visit, the essential number of females necessary is 2107 in a 1-ha Camellia oleifera garden with 1800 plants, while only 1998 female individuals are essentially needed when estimated based on the mean number of pollen grains collected in a single flight period. We argue that the essential number estimated by the former method is more reasonable and accurate for practical applications.