Hormonal interactions underlying parthenocarpic fruit formation in horticultural crops

In some horticultural crops, such as Cucurbitaceae, Solanaceae, and Rosaceae species, fruit set and development can occur without the fertilization of ovules, a process known as parthenocarpy. Parthenocarpy is an important agricultural trait that can not only mitigate fruit yield losses caused by environmental stresses but can also induce the development of seedless fruit, which is a desirable trait for consumers. In the present review, the induction of parthenocarpic fruit by the application of hormones such as auxins (2,4 dichlorophenoxyacetic acid; naphthaleneacetic acid), cytokinins (forchlorfenuron; 6-benzylaminopurine), gibberellic acids, and brassinosteroids is first presented. Then, the molecular mechanisms of parthenocarpic fruit formation, mainly related to plant hormones, are presented. Auxins, gibberellic acids, and cytokinins are categorized as primary players in initiating fruit set. Other hormones, such as ethylene, brassinosteroids, and melatonin, also participate in parthenocarpic fruit formation. Additionally, synergistic and antagonistic crosstalk between these hormones is crucial for deciding the fate of fruit set. Finally, we highlight knowledge gaps and suggest future directions of research on parthenocarpic fruit formation in horticultural crops.

Phenology of Gymnospermium odessanum (DC.) Takht. in the M. M. Gryshko National Botanical Garden of NAS of Ukraine

The aim is to find out the peculiarities of the phenology of the rare endemic species Gymnospermium odessanum (DC.) Takht. in the conditions of introduction on the botanical-geographical plot “Steppes of Ukraine” of the M. M. Gryshko National Botanical Garden, National Academy of Sciences of Ukraine in 2021. Methods — field stationary and cameral. It is established that the vegetation period of G. odessanum in 2021 lasted from March 24 to May 22 and amounted to 60 days. 10 phenological phases are singled out and characterized: 1) the beginning of vegetation and budding, 2) mass budding and beginning of flowering, 3) mass flowering and completion of budding, 4) flowering peak, 5) mass flowering and the beginning of fruit formation, 6) completion of flowering and mass fruit formation, 7) fruit growth, 8) fruit opening, 9) ripening of seeds in open capsules, 10) dissemination and completion of the vegetation. It was found that during the mass formation of fruits, a significant number of fruits stopped their growth and development and did not form seeds in the future. This could be due to the night frosts on the eve or the difference in the conditions of the region of introduction from the natural habitats of the species. Budding and flowering (in total) account for a smaller part (30%) of the vegetation period. Most (70%) of the vegetation period is associated with fruits and seeds. A significant proportion of the vegetation period is the phenophase of ripening of seeds in open capsules (27%).

Description of buckwheat cultivars from Belarus and Ukraine in the environments of Leningrad Province

Background. Buckwheat is an extremely valuable groat crop in demand both in Russia and abroad. The buckwheat collection held by VIR is the largest in the world. Studying and systematizing knowledge about the conserved diversity of the genus Fagopyrum Mill. representatives cannot be efficient without switching to the use of the most detailed descriptors containing plant characters least dependent on differences in growing conditions.Materials and methods. Seventeen buckwheat cultivars from Ukraine and Belarus and two references from Russia were studied in Leningrad Province. The methodological basis of the study included the IPGRI buckwheat descriptors and personal recommendations of N. V. Fesenko. Statistical data processing was performed according to P. F. Rokitsky.Results. The cultivars formed their typical plant habitus and demonstrated good fruit setting − an average score was 3.3–4.9 out of five. The determinant stem growth was observed in 10 cultivars. The stem developed 2.7−6.7 generative nodes and 4–6 vegetative ones, while 1.9–4.7 generative and 0.8−2.3 vegetative nodes were formed on the two upper branches.Conclusion. The study confirmed that medium-ripening buckwheat can be grown in Leningrad Province. The modal value of the number of vegetative nodes for the studied cultivars was 4−5, which is an indicator of intermediate ripening. The results of studying the metamerism of the stem and the two upper branches, expressed by modal values, were recorded in the “agricultural fitness” passport for the tested cultivars as follows: determinant stem; branching zone 4+1+2; fruit-forming zone 3+3+3; average score of fruit formation 4.8. The presented data format most fully characterizes a cultivar in terms of the potential of its earliness and productivity. Depending on the task, indicators for the main stem or for the two upper branches can be used. Recording values in the form of a formula is convenient and does not imply any other meanings.

Flowering phenology and fruit formation of Capparis micracantha in the Bogor Botanic Gardens

Capparis micracantha is a Capparaceae family member. Generally, studies on the phenology of this species have not been widely reported. Current research focuses on the chemical composition and its potential as a medicinal plant. Additionally, another interesting phenomenon of C. micracantha is the presence of black ants. This study aims to ascertain the development of flower and fruit formation, as well as the ant-C. micracantha symbiosis. The observation was conducted from January 2017 until January 2020, twice a week at 08.00, 11.00 a.m, and 02.00 p.m., including the development of the branch, leaves, flowers, and fruit. The results indicated that C. micracantha is a shrub with beautiful flowers, both perfect and imperfect flowers. The number of imperfect flowers is approximately 80% greater than the number of perfect flowers. The fruit is round, green when immature, and red fully mature. The development period from bud into ripe fruit was between 90 and 100 days. February-April, June-August, and October-December are the fruiting seasons. The black ants coexist with this plant in a mutualistic symbiosis.

Changes in physiological and biochemical parameters during the growth and development of guava fruit (Psidium guajava) grown in Vietnam

This research examined the ripening time of guava fruit to provide a scientific basis for better harvesting and preservation of these fruits. Biochemical research methods were used to analyse changes in physiological and biochemical parameters according to the growth and development of guava fruit. The fruit took 14 weeks after anthesis to reach its maximum size in terms of length and diameter. The chlorophyll content in guava peel peaked after 10 weeks, decreasing until week 15. The content of carotenoids, which was low at fruit formation, rose rapidly until fruit ripening, while the vitamin C and reducing sugar contents increased continuously and peaked at week 14. A gradual increase was seen in the starch and total organic acid contents from the beginning of fruit formation, with peaks at 10 weeks, followed by a moderate downward trend. The pectin content showed the same trend, as it declined gradually after peaking at 12 weeks. The first 4 weeks showed an increase in the tannin content, which decreased afterward. The study results show that guava fruit should be harvested after physiological maturity and before ripening completely (14 weeks) to ensure that the nutritional value of the fruit is maintained during storage. Highlights• Xa Li guava at 14 week after anthesis to reach its maximum size in terms of length and diameter. • The chlorophyll content in guava peel peaked after 10 weeks, decreasing until week 15. The content of carotenoids, which was low at fruit formation, rose rapidly until fruit ripening.• The vitamin C and reducing sugar contents peaked at week 14. A gradual increase was seen in the starch and total organic acid contents and peaks at 10 weeks, followed by a moderate downward trend. • The pectin content showed the same trend, as it declined gradually after peaking at 12 weeks. The first 4 weeks showed an increase in the tannin content, which decreased afterward.

Productivity and grain quality indicators of white lupine (Lupinus albus L.) variety Degas when using sodium selenite

The aim of the research was to study the sodium selenite using various methods effect on the yield and quality of Degas variety white lupine grain. To solve these issues microfield experiment on the experimental plot of the Department of agronomic, biological chemistry and radiology of the Russian State Agrarian University - Moscow Timiryazev Agricultural Academy was carried out. Thus, it was found that the use of sodium selenite for foliar treatment of plants contributed to the greatest increase in the yield of white lupine plants. The increase in the grain yield of 27% compared to the control was obtained. The increase in the weight of the beans was revealed by almost 2 times. This indicates the influence of sodium selenite on the processes of fruit formation and the process of laying the seed productivity of lupine plants. The greatest effect of foliar treatment of plants with sodium selenite was found. In this variant, the largest increase in grain yield and the highest content of crude protein in the lupine grain were obtained. It is concluded that the use of selenium affects the formation of beans and grains in them, which determines the increase in plant yield.

ASPECTOS FLORAIS E REPRODUTIVOS DE Psychotria capitata RUIZ & PAVON (RUBIACEAE), UM CASO DE DISTILIA TÍPICA NO CERRADO

BREEDING SYSTEMS AND POLLINATION OF THE PSYCHOTRIA CAPITATA RUIZ & PAVON (RUBIACEAE): A CASE THE TYPICAL DISTYLY IN CERRADO: The phenotypic integration observed in flowers is an evolutionary strategy that aims to increase the pollen flow between individuals, favoring the crossing and maintenance of genetic variability. This success is directly related to the floral structure, such as hermaphroditism, and to the behavior of visitors, and can generate conflicts between the floral structures, being selected characteristics that reduce this conflict and amplify the pollen flow, as is the case of heterostyly. The objective of the study was to describe the floral characteristics, the reproductive system, and pollination in Psychotria capitata Ruiz & Pavon (Rubiaceae). For this purpose, the floral structures were measured and observed, controlled crossings were carried out, the floral visitors were observed and the nectar production was evaluated. Psychotria capitata is a typical dystylic species, shrub with a maximum height of 3 meters, with high rates of reciprocal hercogamy between the floral morphs. It has white tubular flowers, visited by a wide range of insects, including moths, bees, wasps and flies. There was higher fruit formation in intermorphic cross-pollination (> 60 %) and lower formation in intramorphic (< 20 %) and self-pollination (< 15 %), characterizing self and intramorphic incompatibility. These data were confirmed by the non growth of pollen tubes in self-pollinated pistils and intramorphic pollinators. Blooming is annual, and occurs between the months of October and January, with peak blooming in November and December. The reproductive data evaluated are similar to other Rubiaceae species in the Cerrado forest sub forest. These data enrich the reproductive knowledge of Rubiaceae's sub-forest species, so important for the maintenance of fauna in forest fragments.

Biology and distribution of Orchis purpurea subsp. caucasica (Regel) B. Baumann et al. (Orchidaceae Juss.) in the Sochi Black Sea region

Orchis purpurea subsp. caucasica (Regel) B. Baumann, H. Baumann, R. Lorenz et Ruedi Peter is widespreadin the Sochi Black Sea region. It occurs on forest edges and in secondary woodlands of the lower mountain zone. Thenumber in individual populations is from 3 individuals to several dozen, occasionally there are clusters of up to 400individuals. The abundance varies greatly depending on the weather conditions and other factors. The species is winterlate-spring-green with a summer-winter dormant period. The growing season lasts 4–4.5 months. The criterion foridentifying ontogenetic states is the number and size of leaves, the number of leaf veins. Ontogenetic spectra of populationsare single-peaked with a predominance of adults; in more favorable growing conditions, two-peaked with a maximum ofjuveniles. Populations are full-member, normal type, stable. Seed renewal. Fruit formation is about 37.3 %. The numberof seeds in one capsule is from 6 to 28 thousand, one individual produces up to 80 thousand complete seeds per season.Orchis-type seeds, club-shaped, about 0.4 mm long; the embryo is large, round in projection. The species is protected inthe Caucasian State Natural Biosphere Reserve and the Sochi National Park.

Fruit formation of the distylous species Jasminum fruticans L. (Oleaceae)

The article presents the results of a comparative analysis of the fruit formation of long-styled and short-styled plants Jasminum fruticans L. (Oleaceae). The long-styled flowers have larger ovaries and ovules than short-styled ones. Visual signs of degeneration and reduction of the structures of the ovules were not detected. At the same time, the morphs of J. fruticans differ in fruit formation. The proportion of dimeric fruits with two seeds is greater in long-styled plants. Three periods of abortion of fruits/seeds were identified: (1) 1-7 days after flowering correspond to the stage of pollination and fertilization; (2) 8-14 days are the proembryonic stage of embryogenesis; (3) 15-35 days are the stage of globular embryo. The periods of fruits abortion are the same for long- and short-styled plants. Statically significant difference between morph was revealed in the first period of abortion. Differences in morphs of fruits formation indicate less effective pollination and fertilization in short-styled plans. The fruits of J. fruticans mature three months after flowering.