Anther Size Research Articles

The genus Scilla (Hyacinthaceae) in Armenia (an updated review)

The genus Scilla is represented by eight species in Armenia: S. rosenii K. Koch, S. mischtschenkoana Grossh., S. hohenackeri Fisch. & C. A. Mey., S. winogradowii Sosn., S. monanthos K. Koch, S. armena Grossh., S. siberica Haw. and S. caucasica Miscz. There is a great deal of discussion surrounding species growing in Armenia. The scientific literature presents conflicting views on the independence of the species Scilla siberica, S. armena, S. caucasica, S. monanthos and S. winogradowii. The species S. siberica, S. armena, and S. caucasica exhibit morphological similarities that have led to differing interpretations by various authors. Other similar species are S. monanthos and S. winogradowii. The occurrence of S. hohenackeri on the territory of Armenia is uncertain. Consequently, an attempt has been made to clarify the species composition of the Scilla species growing in Armenia and to compile a key for identifying these species. A morphological study of specimens of representatives of the genus Scilla growing on the territory of Armenia revealed previously unnoticed, systematically significant characteristics, such as the colouring of staminal filaments and styles, irregularity of perianth colouring, and anther size. Refinements and additions were made to the morphological descriptions of species of the genus Scilla in the flora of Armenia. Consequently, the species composition of the genus within the territory of Armenia has been considerably updated. According to the results of the obtained data, the independence of the species S. winogradowii, is not accepted, it is considered a synonym of S. monanthos. The independent status of the controversial species S. caucasica and S. armena is maintained. A new population of S. armena has been identified from Mount Aragats, which exhibits morphological and karyological differences from specimens of S. armena from other habitats. The evidence about the presence of S. hohenackeri is considered to be unsubstantiated. It confirmed that six species of the genus Scilla are present in the flora of Armenia: S. armena, S. siberica, S. caucasica, S. monanthos, S. mischtschenkoana and S. rosenii. Additionally, the variety S. siberica var. alba was also identified. A new key for species identification in the Armenian flora was compiled based on the morphological characters.

Exploring genetic variability and molecular-cytogenetic profiling of rye-wheat derivatives

Interspecific plant hybridisation is a pivotal evolutionary process shaping speciation dynamics. In the context of bread wheat cultivation in India, stripe rust stands out as the predominant factor contributing to yield reduction. With the objective of improving stripe rust resistance and floral traits, diverse back-crossed population was meticulously developed through triticale-wheat crosses. The BC2F7 generation of rye-wheat derivatives underwent a comprehensive analysis encompassing genetic variability, trait associations, multiple regressions, and principal component, with a focus on floral and yield attributes. The meticulously chosen stripe rust-resistant derivative lines underwent comprehensive evaluation, including an assessment of chromosomal abnormalities, fluorescence in situ hybridisation, and rye genome-specific molecular markers analysis. The statistical analysis substantiates that the derived population exhibits significant variations for all the examined traits. Positive correlations were observed with anther size, pollen viability, tiller number, thousand kernel weight, and grain yield. Multiple regression analysis reveals that anther size, pollen viability, tiller number, and thousand kernel weights emerge as pivotal contributors influencing grain yield. Moreover, the three principal components exhibit more than one eigen-value, thereby signifying their capacity to encapsulate the maximum variability within the dataset. In addition, chromosomal abnormalities, encompassing univalent, multivalent, laggards, bridge chromosomes, and micronuclei, were observed within the PMCs of rye wheat derivative lines. Fluorescence in-situ hybridisation unequivocally demonstrated rye introgression by green signals. Furthermore, the affirmation of rye introgression was corroborated by rye genome-specific molecular markers. Hence, Comprehensive methods unveil promising traits in rye-wheat lines, advancing wheat breeding in India.

Fine Mapping of qAL5.2 Controlling Anther Length in Oryza sativa.

Anther length is the critical floral trait determining hybrid rice seed production and is controlled by many quantitative trait loci (QTL). However, the cloning of genes specifically controlling anther size has yet to be reported. Here, we report the fine mapping of qAL5.2 for anther size using backcross inbred lines (BILs) in the genetic background of Oryza sativa indica Huazhan (HZ). Gene chip analysis on the BC4F2 and BC5F1 population identified effective loci on Chr1, Chr5, and Chr8 and two genomic regions on Chr5, named qAL5.1 and qAL5.2. qAL5.2 was identified in both populations with LOD values of 17.54 and 10.19, which explained 35.73% and 25.1% of the phenotypic variances, respectively. Ultimately qAL5.2 was localized to a 73 kb region between HK139 and HK140 on chromosome 5. And we constructed two near-isogenic lines (NILs) for RNA-seq analysis, named NIL-qAL5.2HZ and NIL-qAL5.2KLY, respectively. The result of the GO enrichment analysis revealed that differential genes were significantly enriched in the carbohydrate metabolic process, extracellular region, and nucleic acid binding transcription, and KEGG enrichment analysis revealed that alpha-linolenic acid metabolism was significantly enriched. Meanwhile, candidate genes of qAL5.2 were analyzed in RNA-seq, and it was found that ORF8 is differentially expressed between NIL-qAL5.2HZ and NIL-qAL5.2KLY. The fine mapping of qAL5.2 conferring anther length will promote the breed improvement of the restorer line and understanding of the mechanisms driving crop mating patterns.

Two lineages of Lemna aequinoctialis (Araceae, Lemnoideae) based on physiology, morphology, and phylogeny.

Lemna aequinoctialis Welw. is a widely spread species that has diverse physiological and molecular properties. Flower characteristics are important factors in deducing taxonomical status; however, owing to the rarity of flowering observations in Lemna, studying them has been a prolonged challenge. In this study, physiological and morphological analyses were conducted by inducing flowering, and molecular analysis was done based on the two chloroplast DNA loci (matK, atpF-atpH intergeneric spacer) of L. aequinoctialis sensu Landolt (1986) from 70 strains found in 70 localities in Japan, Korea, Thailand, and the US. In total, 752 flowering fronds from 13 strains were observed based on axenic conditions. Two different trends in flower organ development-protogyny and adichogamy-were detected in these strains. Their physiological traits were divided into two groups, showing different morphological features based on frond thickness, root cap, and anther sizes. Molecular analysis showed two lineages corresponding to two physiological groups. These were identified as L. aequinoctialis sensu Beppu et al. (1985)and L.aoukikusa Beppu et Murata based on the description of the nomenclature of L. aoukikusa. These were concluded as independent taxa and can be treated as different species. Furthermore, the distribution of L. aoukikusa is not only limited to Japan.

Allium serpenticola (A. sect. Codonoprasum, Amaryllidaceae), a new species from Türkiye

Allium serpenticola Eker, a new species in sect. Codonoprasum, is described and illustrated from Adana, Türkiye. It is similar to Allium stamineum Boissier, but different in many morphological characters, especially including colors of perigone, pedicels and anthers, length of spathe valves and their ratio to umbel, length of filaments and their ratio to perigone, anther size, constant style length, number of leaves, proportion of sheats surrounding scape, outer tunic colour and seed ornamentation. A comprehensive description of this species is provided, including detailed illustrations and photographs, geographical distribution, habitat and ecology, and IUCN conservation status. Micromorphological characteristics of A. serpenticola and A. stamineum seeds are also examined and compared using stereomicroscope and SEM analyses.

Exploitation of Wheat Genome through Triticale x Wheat Cross for Improvement and Identification of Large Anther

Triticale is a man-made cereal crop that combines the rye and wheat genome in a single crop. Rye is a cross pollinated cereal crop that has large anther size in comparison of wheat. To improve wheat anther size, cross with triticale is a noble practice to combine the A, B, D and R genome. In the current investigation wheat (AABBDD) were crossed with triticale (AABBRR) with the help of Ph suppressor Chinese Spring. Subsequently triticale wheat derivative lines populations were developed. The BC2F7 generations of the derived population were planted in alpha lattice design to further evaluation. With the help of fixative, the fresh spikes were collected from individual derivative lines to measure anther the size. The anther size was measured in millimeter by the help of ocular micrometer. Twenty-two triticale wheat derivative lines were identified with grater anther size in comparison of triticale anther. The TWD26 (5.7mm) has larger anther size followed by TWD18 (5.4mm) and TWD36 (5.3mm). These derivative lines may use as a donor parent in hybrid wheat breeding programme.

Effects of Functional Materials and Fertilizer Application on the Growth and Physiological Indicators of Pearl Apricot

In order to study the effects of different amount of functional materials (FM) on pearl oil apricot, the study set up 0 g (control), 50 g (FM50), 200 g (FM200) and 300 g (FM300) of functional materials, and mixed with 2 kg of compound fertilizer as the base fertilizer. The growth and physiological indexes of pearl oil apricot and soil physicochemical properties were measured. Results showed that FM treatment significantly improved the pollen viability especially under FM300 treatment. FM200 and FM300 treatments significantly improved leaf carotenoids, anther size and anther quality of 100 seeds compared with the control. The anther width was significantly increased by 0.13 mm at FM300. However, physiological indexes such as filament length, anther length, pistil development type, hundred leaves length, hundred leaves width, hundred leaves thickness, hundred leaves weight and pollen fullness were not affected by FM. It can be seen that FM had a greater effect on growth and physiology indicators of pearl oil apricot, while the effect on soil physicochemical properties was smaller.

Stamen and pollen heteromorphism linked to the division of labour in Melastomataceae species

The occurrence of stamen heteromorphism within pollen flowers (or heteranthery) has been mostly explained by a division of labour hypothesis, which suggests that some anthers produce pollen for pollination (pollinating anthers) while others are specialized in attracting and rewarding floral visitors (feeding anthers). Despite more than 20.000 species presenting stamen heteromorphism, the morphological and functional traits associated with it have been poorly investigated, especially at the pollen level. Here we evaluated the structural and possible functional roles of stamen and pollen heteromorphism in 16 Melastomataceae species belonging to four tribes. We investigated how a number of traits associated with floral heteromorphisms - anther size, pollen quantity and quality, pollen volume and exine ornamentation - might interact with pollination efficacy and pollinator feeding behaviour. Our results showed morphological differences between anthers and pollen grains that might affect pollinating and feeding functions in the studied species. Pollinating anthers were larger and produced more numerous and more viable pollen grains than feeding anthers. Pollen grain volume between the anther sets was mostly similar in the analysed species, with the exception of three species. Three species of tribe Microlicieae and one from the Marcetieae presented differences in pollen exine ornamentation between pollinating and feeding anthers. Overall, our findings support the division of labour hypothesis for some, but not all, species included in our study. We showed that stamen heteromorphism on the 16 studied species may lead to subtle and specific differences in anthers and pollen morphology which may contribute to their functional role.

A bifunctional selectable marker for wheat transformation contributes to the characterization of male-sterile phenotype induced by a synthetic Ms2 gene.

An engineered selectable marker combining herbicide resistance and yellow fluorescence contributes to the characterization of male-sterile phenotype in wheat, the severity of which correlates with expression levels of a synthetic Ms2 gene. Genetic transformation of wheat is conducted using selectable markers, such as herbicide and antibiotic resistance genes. Despite their proven effectiveness, they do not provide visual control of the transformation process and transgene status in progeny, which creates uncertainty and prolongs screening procedures. To overcome this limitation, this study developed a fusion protein by combining gene sequences encoding phosphinothricin acetyltransferase and mCitrine fluorescent protein. The fusion gene, introduced into wheat cells by particle bombardment, enabled herbicide selection, and visual identification of primary transformants along with their progeny. This marker was then used to select transgenic plants containing a synthetic Ms2 gene. Ms2 is a dominant gene whose activation in wheat anthers leads to male sterility, but the relationship between the expression levels and the male-sterile phenotype is unknown. The Ms2 gene was driven either by a truncated Ms2 promoter containing a TRIM element or a rice promoter OsLTP6. The expression of these synthetic genes resulted in complete male sterility or partial fertility, respectively. The low-fertility phenotype was characterized by smaller anthers than the wild type, many defective pollen grains, and low seed sets. The reduction in the size of anthers was observed at earlier and later stages of their development. Consistently, Ms2 transcripts were detected in these organs, but their levels were significantly lower than those in completely sterile Ms2TRIM::Ms2 plants. These results suggested that the severity of the male-sterile phenotype was modulated by Ms2 expression levels and that higher levels may be key to activating total male sterility.

ZmMs33 promotes anther elongation via modulating cell elongation regulators, metabolic homeostasis, and cell wall remodeling in maize

Plant cell elongation depends on well-defined gene regulations, adequate nutrients, and timely cell wall modifications. Anther size is positively correlated with the number and viability of pollen grains, while little is known about molecular mechanisms underlying anther cell elongation. Here, we found that properly activated cell elongation regulators at transcriptional levels in loss-of-function ZmMs33 mutant (ms33-6038) anthers failed to promote maize anther elongation. ZmMs33 deficiency disrupted metabolic homeostasis mainly by inhibiting both photosynthesis in anther endothecium and lipid accumulation in anther tapetum. Importantly, ms33-6038 anthers displayed ectopic, premature and excessive secondary cell wall thickening in anther middle layer, which constrained cell elongation structurally and blocked nutrient flows across different anther wall layers. The metabolic disorder was only found in ms33-6038 mutant rather than several representative male-sterility lines at transcriptional and post-translational levels. Collectively, the disordered metabolisms and blocked nutrient flows defeated the activated cell elongation regulators, and finally inhibited anther elongation and growth with a unique “idling effect” in ms33-6038 mutant.

Research and utilization of mixed seed production technology for two-line hybrid wheat

<p indent="0mm">China’s Two-line Hybrid Wheat Technology System is an important achievement resulting from novel domestic use of sterile lines to realize agroindustrial application of hybrid wheat. However, compared with hybrid rice and maize, the industrial application level of hybrid wheat is still in its early stage. The unstable production of hybrids, as well as their high cost and the large sowing amount of seeds required for their cultivation, have always limited the rapid industrialization of two-line hybrid wheat. Two-line hybrid wheat research and cultivation show that high-efficiency seed production is the core key technology for the successful industrialization of hybrid wheat. Moreover, the outcrossing performance of wheat photo-thermo sensitive sterile lines is the key to the success of seed production. Wheat photo-thermo sensitive sterile lines can change from selfing to outcrossing under seed production conditions, and their seed production characteristics are affected by various factors of both sterile lines and restorer lines. Breeding sterile lines and restorer lines with high combining ability and excellent outcrossing traits can effectively improve the seed setting rate and yield of outcrossing in seed production and also greatly reduce the cost of wheat hybrid seed production. In our study, the influencing factors and results of the seed production process were assessed based on related seed production experiments with two-line hybrid wheat conducted from 2016 to 2020. Outcrossing traits, such as female bloom traits of floret opening size and stigma exposure rate and male fertility traits of pollen dispersal distance, anther size, anther exposure rate, and pollen amount were significantly correlated with outcrossing performance. In the pollination stage, larger pollen amounts, shorter pollen dispersal distances, longer pollination durations of the restorer line, higher stigma exposure rates, and larger floret opening angles of the sterile line can greatly improve the outcrossing seed setting rate, production yield, and quality of the sterile line. The flowering period of male parents was 2–3 days later than that of female parents, which could be utilized to realize the effective preparation of temporal-spatial and physiological synergy. With the male parent comprising 5% of a mixed population, the yield of mixed seed production was significantly increased by 28.2% compared with even row ratio seed production. From 2019 to 2021, large-scale mixed seed production in the Nanyang area has achieved excellent results with large-scale seed production of BS1453/JS1 reaching 5273.4 kg/hm². The establishment of a simple, scientific, safe, and efficient technology system for large-scale mixed seed production has solved the technical bottleneck of large-scale seed production of two-line hybrid wheat, providing theoretical and technical support for the popularization and widespread application of two-line hybrid wheat.

Hydroxyproline-O-Galactosyltransferases Synthesizing Type II Arabinogalactans Are Essential for Male Gametophytic Development in Arabidopsis.

In flowering plants, male reproductive function is determined by successful development and performance of stamens, pollen grains, and pollen tubes. Despite the crucial role of highly glycosylated arabinogalactan-proteins (AGPs) in male gamete formation, pollen grain, and pollen tube cell walls, the underlying mechanisms defining these functions of AGPs have remained elusive. Eight partially redundant Hyp-galactosyltransferases (named GALT2-GALT9) genes/enzymes are known to initiate Hyp-O-galactosylation for Hyp-arabinogalactan (AG) production in Arabidopsis thaliana. To assess the contributions of these Hyp-AGs to male reproductive function, we used a galt2galt5galt7galt8galt9 quintuple Hyp-GALT mutant for this study. Both anther size and pollen viability were compromised in the quintuple mutants. Defects in male gametogenesis were observed in later stages of maturing microspores after meiosis, accompanied by membrane blebbing and numerous lytic vacuoles. Cytological and ultramicroscopic observations revealed that pollen exine reticulate architecture and intine layer development were affected such that non-viable collapsed mature pollen grains were produced, which were devoid of cell content and nuclei, with virtually no intine. AGP immunolabeling demonstrated alterations in cell wall architecture of the anther, pollen grains, and pollen tube. Specifically, the LM2 monoclonal antibody (which recognized β-GlcA epitopes on AGPs) showed a weak signal for the endothecium, microspores, and pollen tube apex. Pollen tube tips also displayed excessive callose deposition. Interestingly, expression patterns of pollen-specific AGPs, namely AGP6, AGP11, AGP23, and AGP40, were determined to be higher in the quintuple mutants. Taken together, our data illustrate the importance of type-II AGs in male reproductive function for successful fertilization.

Size-dependent sex allocation in Solanum lycocarpum St. Hil. (Solanaceae).

Resource allocation to reproduction can change depending on size, as predicted by the size-dependent sex allocation. This theory is based on the fact that small individuals will invest in the allocation of sex with lower cost of production, usually male gender. In plants, there are some andromonoecy species, presence of hermaphrodite and male flowers in the same individual. Andromonoecy provides a strategy to optimally allocate resources to male and female function, evolving a reproductive energy-saving strategy. Thus, our objective was to investigate the size-dependent sex allocation in Solanum lycocarpum St. Hil. We tested the hypothesis that plants with larger size will invest in the production of hermaphrodite flowers, because higher individuals have greater availability of resources to invest in more complex structures involving greater energy expenditure. The studied species was S. lycocarpum, an andromonoecious species. From June 2016 to March 2017 the data were collected in 38 individuals, divided in two groups: the larger plant group (n=18; height=3-5 m) and the smaller plant group (n=20; height=1-2 m).Our data show that there was effect of plant size on the flower production and the sexual gender allocation. The larger plants showed more flowers and higher production of hermaphrodite flowers. Furthermore, in the flower scale, we observed allometric relationship among the flower's traits with proportional investments in biomass, anther size and gynoecium size. Our results are in agreement with size-dependent sex allocation theory and andromonoecy hypothesis related to mechanisms for optimal resource allocation to male and female function.

Eggplant Anther Culture: Association Between Bud/Anther Size and Microspore Developmental Stage in Different Eggplant Genotypes

Anther culture is a valuable method for obtaining haploid and doubled haploid (DH) plants from microspores and there are several factors influencing the induction of androgenesis such as genotype and microspore development stage. The aim of the present work was, therefore, to identify the bud stages, with maximum amount of young microspores (YM) and mid microspores (MM), thought to be most responsive to embryogenesis induction in anther cultured, and to investigate the influence of genotype on embryogenesis. In this work, first of all anthers and buds containing the highest percentage of YM and MM in four different F1 eggplant genotypes were identified. Results revealed that a certain bud/ anther size group in each genotype might correspond to different microspore / pollen development stage in different genotypes. After determining the best anther length in order to increase the presence of YM and MM corresponding anthers were collected for four genotypes and cultured. Embryo and regenerated plantlet production were taken into consideration to evaluate the response to anther culture for each genotype. Embryos were obtained in all 4 genotypes with variable percentages, ranging from 3,57% to 40.67 %. As a conclusion, related bud and anther length determined for each genotype could be used as fast and reliable criteria to determine the most responsive microspore/pollen developmental stage, which has maximum amount of YM and MM, to increase the efficiency in eggplant anther culture.

Distinct pollen release dynamics between stamens generate division of labour in pollen flowers of two Pleroma species (Melastomataceae)

Flowers that provide only pollen to pollinators should maximize pollen release for reproduction while minimizing pollen loss through consumption by bees. In flowers that are polymorphic for stamen type, the number of pollen grains produced as well as stamen morphology likely influences pollen release dynamics and favor the division of labor between stamens with different functions. However, few studies have evaluated such predictions. In this study, we tested the “division of labor hypothesis” considering not only the stamen morphology of pollen flowers but also their pollen release dynamics. Stamen morphology as well as the amount and viability of pollen were characterized in two Melastomataceae species, Pleroma granulosum and Pleroma raddianum. Using artificial vibrations, we estimated pollen release dynamics throughout anthesis in the anthers of short and long stamens from flowers of both species. P. granulosum flowers presented low heteranthery (i.e., anthers differed by only about 1 mm in length) and short stamens produced fewer pollen grains in both species. We also found similarly high viability of pollen from all anthers of both species. Although pollen grain release increased in all anthers over the flower´s lifespan, their dynamics were different between the two stamen sets in both species. Anthers of shorter stamens tended to release fewer and proportionally lower quantities of pollen grains at each time interval than anthers of longer stamens. Our study suggests that the number of pollen grains produced, as well as stamen morphology (beyond anther size) may control pollen release dynamics, leading to a division of labor between stamens in these pollen flowers.

Pollination efficiency and pollen limitation in bistaminate vs tetrastaminate Lamiaceae

AbstractThe evolution of bilabiate flowers in Lamiaceae has several times led to a reduction in stamen number. It is generally assumed that stamen reduction goes along with decreasing pollen production. One should, therefore, expect that bistaminate flowers have either a more efficient pollen transfer mechanism or a higher selfíng rate than tetrastaminate species to adapt to the stamen reduction. We tested this hypothesis in a community of Lamiaceae including three bistaminate and three tetrastaminate species. The results of selfing experiments, extra‐pollination, counting pollen number, and stigmatic pollen load analysis were used to calculate the autonomous selfing index, the pollen limitation index, and the pollination efficiency index. The results indicate a significantly lower pollen number in bistaminate flowers than in tetrastaminate flowers of similar anther size. Bistaminate species shared a higher selfing rate which was related to their structural adaptation to delayed selfing. In Ziziphora clinopodioides, the delayed selfing was accompanied by low pollination efficiency, and plants suffered from pollen limitation at the location studied. However, in Salvia sclarea and Salvia hypoleuca, which benefited from a relatively high pollination efficiency, no pollen limitation was observed. Our results reveal a close association between adaptive mechanisms such as increasing precision of pollen transfer and evolution of delayed selfing with stamen reduction in bistaminate Lamiaceae.

Association of flower color with pollen reward may explain increased bumblebee visitation to the Scotch broom yellow morph

Given that pollinators usually visit flowers for hidden rewards, they need to rely on floral traits that indicate reward status (“honest signals”). However, the relationship between pollination, honest signals, and floral rewards is little documented in natural conditions. The Scotch broom (Cytisus scoparius) is an invasive shrub with polymorphism in the color of its flowers that can be yellow, orange, or red. In three areas dominated by the Scotch broom, we described the abundance of the floral morphs and estimated bumblebee (Bombus terrestris) visitation rate. We examined whether bumblebee visitation to the floral morphs was related to pollen reward. We collected flowers and classified their stamens according to their function: reward or pollen export. Then, we measured anther size and estimated pollen quantity. The yellow morph was more abundant and more visited by bumblebees than the orange and red morphs. The yellow flowers did indeed offer more pollen than the other morphs and this occurred only for rewarding anthers, suggesting that bumblebees could use yellow color as an honest signal to visit the most rewarding flowers. We discuss whether innate and/or learned preferences of bumblebees can explain why the yellow morph is more visited, pollinated, and abundant, while the other morphs are maintained at a lower frequency. This is one of the few field works that shows that variation in intra-specific floral traits is associated with variation in floral reward and pollinator visitation rate, helping to understand the foraging preferences of pollinators and the coexistence of floral morphs in nature. Clinical trials registration: Not applicable.

Development and structure of four different stamens in Clematis macropetala (Ranunculaceae): particular emphasis on staminodes and staminal nectary.

The stamens of angiosperms are diverse in number, colour and structure. The morphological and structural changes of stamens show important evolutionary significance for improving pollination efficiency. In Clematis macropetala, the androecium consists of fertile stamens and tepaloid staminodes. However, studies on the developmental features, structures and possible functions of stamens are few. In this study, the stamen ontogeny, micromorphology and nectary structure of C. macropetala were studied by scanning electron microscopy, light microscopy and transmission electron microscopy. The results indicate that the stamens can be divided into four forms according to shape and anther size: tepaloid staminode (St1), spatulate staminode (St2), linear-spatulate fertile stamen (St3) and linear fertile stamen (St4). The characteristics of stamen development are similar in the early stage but gradually differentiate in the later stage. St1 has delayed development and no anther differentiation. St2 develops abnormally at the early stage of anther differentiation. St3 and St4 are fertile, but their anther sizes are different. Nine epidermal cell types were observed in stamens, with only 4 types in St1 and 6-7 types in St2, St3 and St4. Nectary tissue appears on the adaxial side of the filament base. The nectary is composed of only one layer of secretory epidermal cells, which have a large nucleus, dense cytoplasm and well-developed wall ingrowth. Nectar is released through micro-channels in the cuticle of the outer wall. In Ranunculaceae, the staminal nectary is often located on fertile or sterile stamens, and the position, structure and micromorphology of secretory tissues of the stamen within Ranunculales are discussed.

Phenotyping Anther Extrusion of Wheat Using Image Analysis

Phenotyping wheat (Triticum aestivum L.) is time-consuming and new methods are necessary to decrease labor. To develop a heterotic pool of male wheat lines for hybrid breeding, there must be an efficient way to measure both anther extrusion and the size of anthers. Five hundred and ninety-four soft red winter wheat lines in two replications of randomized complete block design were phenotyped for anther extrusion, a key trait for hybrid wheat production. A device was constructed to capture images using a mobile device. Four heads were sampled per line when anthesis was evident for half the heads in the plot. The extruded anthers were scraped onto a surface, their image was captured, and the area of the anthers was taken via ImageJ. The number of anthers extruded was estimated by counting the number of anthers per image and dividing by the number of heads sampled. The area per anther was taken by dividing the area of anthers per spike by the number of anthers per spike. A significant correlation (R=0.9, p&lt;0.0001) was observed between the area of anthers per spike and the number of anthers per spike. This method is proposed as a substitute for field ratings of anther extrusion and to quantitatively measure the size of anthers.

Morphological Variability of Nitraria Species in Central and Southern Kazakhstan

The variability of metric traits has been studied in 20 Kazakhstan populations of three Nitraria species (N. schoberi L., N. sibirica Pall., and N. komarovii Iljin & Lava ex Bobrov). According to the results, N. sibirica differs from N. schoberi and N. komarovii in small leaves, fruits, and seeds, as well as in the structural features of inflorescences and flowers. N. sibirica is characterized by a greater number of flowers per inflorescence (25–66 on average) than N. schoberi and N. komarovii (14–28 on average). Additionally, N. sibirica differs from N. schoberi by narrower (1.3×) petals and smaller anthers (1.46× in length and 1.2× in width) and pistils (1.25× in length and 1.44× in width). N. komarovii differs from N. schoberi by narrower leaves (1.7×). N. komarovii is characterized by relatively large (especially in width) size of anthers that, together with smaller petals, makes it possible to distinguish this species during flowering. Flowers of N. komarovii are bright yellow, while those in N. schoberi and N. sibirica are white and light purple, respectively. N. komarovii fruits are orange, pale red, or bright red. Fruits of N. schoberi and N. sibirica are dark burgundy and black, respectively. At the intraspecific level, most of the studied metric traits (except for the habitus of N. sibirica plants) are stable and do not depend on the 16 climatic parameters of plant habitats. At the same time, a number of morphological features have been revealed in N. sibirica plants from the Ili Depression. In these populations, N. sibirica plants form shrubs up to 1.8 m in height with a large (up to 90) number of flowers per inflorescence, large petals (3.5 mm in length and 2.2 mm in width on average), small (~0.6 mm) anthers, small (5–5.5 mm in length) fruits, and small (~4 mm in length) narrow ovate stones. These features indicate the ecological–geographical differentiation of N. sibirica under the extra-arid conditions of the stony desert of the depression and evidence a separate taxonomic rank of these populations.