Polymorphism of traits of flower and fruit of the Tsumi apple tree (Malus zumi (Matsum.) Rehder)

The Tsumi apple tree is a valuable crop due to the presence of a gene for resistance to powdery mildew, abundant annual fruiting and a special decorative effect during flowering and fruiting. Its breeding potential has been little studied; therefore, it is necessary to study the morphometric characteristics of a flower and a fruit and establish connections between them. The collection of flowers and fruits of the Tsumi apple tree was carried out in the laboratory of cultivated plants of the Tsytsin Main Botanical Garden in 2021. The coefficients of variation and correlation according to Spearman were determined. It was found that the polymorphism of flower traits is at a very low level (from 4.4% to 14.2%). The number of flowers per inflorescence varies within 15.9%, which corresponds to the average level of polymorphism, as well as in the weight of the fruit (17.3%) and in the weight of seeds (19.5%). Variations in the length of the peduncle, the number of seeds, the length of the fruit, and the diameter of the fruit are at a very low level (6.9-13.6%). A significant number of reliable inverse (negative) correlations were found between signs of moderate strength (0.5 <r <0.6): a strong relationship between fruit weight and anther length (r = -0.73), fruit length and filament length (r = -0.71). A strong positive relationship was found between the following traits: fruit weight and fruit diameter (r = 0.79), seed weight. Keywords: POLYMORPHISM, FLOWER, CRABAPPLES, SORBOMALUS, MALUS ZUMI, TSUMI APPLE TREE, VARIABILITY, MORPHOLOGY

Naïve and Experienced Honeybee Foragers Learn Normally Configured Flowers More Easily Than Non-configured or Highly Contrasted Flowers

Angiosperms have evolved to attract and/or deter specific pollinators. Flowers provide signals and cues such as scent, colour, size, pattern, and shape, which allow certain pollinators to more easily find and visit the same type of flower. Over evolutionary time, bees and angiosperms have co-evolved resulting in flowers being more attractive to bee vision and preferences, and allowing bees to recognise specific flower traits to make decisions on where to forage. Here we tested whether bees are instinctively tuned to process flower shape by training both flower-experienced and flower-naïve honeybee foragers to discriminate between pictures of two different flower species when images were either normally configured flowers or flowers which were scrambled in terms of spatial configuration. We also tested whether increasing picture contrast, to make flower features more salient, would improve or impair performance. We used four flower conditions: (i) normally configured greyscale flower pictures, (ii) scrambled flower configurations, (iii) high contrast normally configured flowers, and (iv) asymmetrically scrambled flowers. While all flower pictures contained very similar spatial information, both experienced and naïve bees were better able to learn to discriminate between normally configured flowers than between any of the modified versions. Our results suggest that a specialisation in flower recognition in bees is due to a combination of hard-wired neural circuitry and experience-dependent factors.

Nectar Chemistry or Flower Morphology—What Is More Important for the Reproductive Success of Generalist Orchid Epipactis palustris in Natural and Anthropogenic Populations?

The aim of this study was to determine the level of reproductive success (RS) in natural and anthropogenic populations of generalist orchid Epipactis palustris and its dependence on flower structure and nectar composition, i.e., amino acids and sugars. We found that both pollinaria removal and female reproductive success were high and similar in all populations, despite differences in flower traits and nectar chemistry. Flower structures were weakly correlated with parameters of RS. Nectar traits were more important in shaping RS; although, we noted differentiated selection on nectar components in distinct populations. Individuals in natural populations produced nectar with a larger amount of sugars and amino acids. The sucrose to (fructose and glucose) ratio in natural populations was close to 1, while in anthropogenic ones, a clear domination of fructose and glucose was noted. Our results indicate that the flower traits and nectar composition of E. palustris reflect its generalist character and meet the requirements of a wide range of pollinators, differing according to body sizes, mouth apparatus, and dietary needs. Simultaneously, differentiation of nectar chemistry suggests a variation of pollinator assemblages in particular populations or domination of their some groups. To our knowledge, a comparison of nectar chemistry between natural and anthropogenic populations of orchids is reported for the first time in this paper.

Response of Apple Trees (cv. Ibrahimi) to the Time of Foliar Application with Zinc and Boron

The study was conducted in one of the private orchards in the Saqlawiya area - Fallujah during the 2020 growing season. The foliar spray was used to study the effect of the timing of foliar spraying (three sprays, the first at the beginning of flowering, second at the stage of full flowers blooming, and the third at the stage of petal fall), Presented with symbols (D1, D2 and D3), respectively. The second factor consisted of spraying with boron and zinc with the following concentrations (0,1, and 3 gm. L-1), mentioned as (S0, S1, S2, S3), respectively. these elements were used singly or in the form of a mixture with the same concentrations. This study aims to study the effect of the two factors on the growth and setting of apple trees, cv. Ibrahimi. Therefore, (36) five-year-old apple trees with homogeneous vegetative growth were selected as much as possible. The results revealed that foliar application with boron and zinc for the Ibrahimi apple trees improved the quality of the fruits and their vegetative and flowering traits. The results revealed that spraying with micronutrients at the stage of petal fall had a significant effect on flower traits and yield especially the media culture (M3) which presented the best results for the traits. The results revealed that spraying with micronutrients at the stage of petal fall had a significant effect on flower traits and yield especially the time (D3) which presented the best results for the traits (leaf area, Rate of increase in the length of the branches, Rate of increase in branch diameters, Fruits set Percentage, Percentage of fallen fruits and Percentage of remaining fruits, which reached (24.25cm2, 56.77cm, 0.42cm, 26.65%, 45.25%, 54.75%), respectively. On the other hand, spraying with micronutrients achieved significant effect, especially (S3), that gave the highest values for the traits (Rate of increase in branch diameters, Fruits set Percentage, Percentage of fallen fruits and Percentage of remaining fruits), which were (37.50 cm, 0.42%, 26.65%, and 46.71 gm L-1).

Floral Nectar Chemistry in Orchids: A Short Review and Meta-Analysis

Nectar is one of the most important flower traits, shaping plant–pollinator interactions and reproductive success. Despite Orchidaceae including numerous nectariferous species, nectar chemistry in this family has been infrequently studied. Therefore, the aim of this study is to compile data about nectar attributes in different orchid species. The scarcity of data restricted analyses to sugar concentration and composition. Our results suggest that the most important factor shaping nectar traits in orchids is the pollinator type, although we also found differentiation of nectar traits according to geographical regions. In spurred orchids, the length of the spur impacted nectar traits. We recommend the development of studies on nectar chemistry in orchids, including a wider range of species (both in taxonomic and geographical contexts), as well as extending the analyses to other nectar components (such as amino acids and secondary metabolites). The nectar biome would be also worth investigating, since it could affect the chemical composition of nectar. This will enrich the understanding of the mechanisms of plants–pollinators interactions.

Identification of QTLs and Candidate Genes Related to Flower Traits and Bolting Time in Raphanus sativus

Radish flower color, bolting time, and flowering time are important traits for attracting certain pollinators and affect fleshy root quality. In this study, an analysis of the anthocyanidins in radish flowers by high-performance liquid chromatography revealed that differences in the cyanidin content are likely to be associated with the variability in radish flower colors (i.e., purple and white petals). A quantitative trait loci (QTL) analysis identified nine QTLs on three Raphanus sativus linkage groups. Three QTLs—qRFC1, qRBT1, and qRFT1—which were consistently detected and explained a high proportion of the observed variation (10.30% to 34.57%), were considered as the major QTLs responsible for flower color, bolting time, and flowering time, respectively. A total of 16 and 11 candidate genes within the major QTL regions for flower color and bolting/flowering times, respectively, were preliminarily annotated. Six genes (Rs018140, Rs018950, Rs019220, Rs020080, Rs020590, and Rs021450) related to flower color were differentially expressed in the parental lines. On the basis of nucleotide and amino acid sequence diversity between the parental lines, Rs314940, Rs315000, Rs315310, and Rs315960 were identified as candidate genes mediating the radish bolting and flowering times. This study revealed the genetic complexity of the radish flower color, bolting time, and flowering time traits. The identified candidate genes in the QTL regions may be useful for radish breeding programs and also for functional characterization in radish.

Inbreeding in a dioecious plant has sex- and population origin-specific effects on its interactions with pollinators

We study the effects of inbreeding in a dioecious plant on its interaction with pollinating insects and test whether the magnitude of such effects is shaped by plant individual sex and the evolutionary histories of plant populations. We recorded spatial, scent, colour and rewarding flower traits as well as pollinator visitation rates in experimentally inbred and outbred, male and female Silene latifolia plants from European and North American populations differing in their evolutionary histories. We found that inbreeding specifically impairs spatial flower traits and floral scent. Our results support that sex-specific selection and gene expression may have partially magnified these inbreeding costs for females, and that divergent evolutionary histories altered the genetic architecture underlying inbreeding effects across population origins. Moreover, the results indicate that inbreeding effects on floral scent may have a huge potential to disrupt interactions among plants and nocturnal moth pollinators, which are mediated by elaborate chemical communication.

Evolution of Bird and Insect Flower Traits in Fritillaria L. (Liliaceae)

Pollinators are often perceived as a primary selective agent influencing flower traits such as colour, size, and nectar properties. The genus Fritillaria L. (Liliaceae), comprising approximately 150 species, is described as generally insect pollinated. However, there are at least three exceptions: two hummingbird-pollinated North American species and one passerine-pollinated Asian species. Despite this variation in pollination, little is known about flower traits that may accompany this shift in fritillaries. In this study, we aimed to assess the attractiveness of the floral traits for (new) pollinators and track the evolution of flowers traits in the context of a shift in the principal pollinator. Therefore, we studied 14 flower traits related to the pollination in 60 Fritillaria species and traced the evolutionary trajectory of these traits. We used a phylogenetic tree of the genus, based on five DNA markers (matK, rpl16, and rbcL, 18S, and ITS) to reconstruct the ancestral state of studied flower traits. The results show that in bird-pollinated species several new traits evolved. For example, flower colouration, nectar sugar, and amino acid concentration and composition fulfil the criteria of ornithophilous flowers, although flower traits do not exclude insect pollinators in bird-pollinated fritillaries. Interestingly, we recorded potential reversals from bird to insect pollination. Our analysis, showing a broad study of flower traits among closely related species in the context of pollinator shift, serves as a starting point for future work exploring the genetic and physiological mechanisms controlling flower traits in the genus Fritillaria.

How Are the Flower Structure and Nectar Composition of the Generalistic Orchid Neottia ovata Adapted to a Wide Range of Pollinators?

Plant-pollinator interactions significantly influence reproductive success (RS) and drive the evolution of pollination syndromes. In the context of RS, mainly the role of flower morphology is touched. The importance of nectar properties is less studied, despite its significance in pollination effectiveness. Therefore, the aim of this study was to test selection on flower morphology and nectar chemistry in the generalistic orchid Neottia ovata. In 2019–2020, we measured three floral displays and six flower traits, pollinaria removal (PR), female reproductive success (FRS), and determined the soil properties. The sugars and amino acids (AAs) were analyzed using the HPLC method. Data were analyzed using multiple statistical methods (boxplots, ternary plot, one-way ANOVA, Kruskal-Wallis test, and PCA). Variation of flower structure and nectar chemistry and their weak correlation with RS confirms the generalistic character of N. ovata. In particular populations, different traits were under selection. PR was high and similar in all populations in both years, while FRS was lower and varied among populations. Nectar was dominated by glucose, fructose, and included 28 AAs (Ala and Glu have the highest content). Sugars and AAs influenced mainly FRS. Among soil parameters, carbon and carbon:nitrogen ratio seems to be the most important in shaping flower structure and nectar chemistry.