Artificial Hybrids Research Articles

Phenotypic traits of reciprocal tetraploid hybrids derived from tetraploid Crassostrea gigas and tetraploid Crassostrea angulata

Allotetraploid has the potential to become an important germplasm resource for genetic breeding of organisms. Previously, autotetraploid oysters have played a great role in the worldwide triploid oyster industry by mating with diploids to produce triploid seeds. However, whether allotetraploid oysters can be produced and their performance is unknown. Here, we carried out an artificial interspecific cross between tetraploid Crassostrea gigas and teraploid C. angulata, forming 4 experimental groups, two autotetraploid groups (GGGG: tetraploid C. gigas♀ × C. gigas♂, AAAA: C. angulata♀ × C. anguata♂) and two allotetraploid groups (GGAA: C. gigas♀ × C. anguata♂, AAGG: C. angulata♀ × C. gigas♂). These two pure tetraploid species hybridized without barrier to gamete reproductive isolation, resulting in high fertilization rate (>93%) and acceptable hatching rate (>78%). Reciprocal tetraploid hybrid survival rates were higher than that of pure tetraploids. Some degree of growth heterosis was observed, especially for yearlings. Mid-parent heterosis of wet weight and shell height at day 360 was 31.58% and 16.11%, respectively, which were primarily influenced by egg origin and mating strategy. Overall, the order of performance of the four groups in the warm water area was as following: AAGG>GGAA>AAAA>GGGG. Our results demonstrate that artificial interspecific hybridization between two tetraploid oysters can produce heterosis and that teraploid hybrids have the potential to become new genetic resources for the improvement of polyploid oysters.

Selective miR-21 detection technology based on photocrosslinkable artificial nucleic acid-modified magnetic particles and hybridization chain reaction

Recently, microRNA (miRNA) detection in blood has attracted attention as a new early detection technology for cancer. The extraction of target miRNA is a necessary preliminary step for detection; however, currently, most extraction methods extract all RNA from the blood, which limits the detection selectivity. Therefore, a method for the selective extraction and detection of target miRNA from blood is very important. In this study, we utilized photocrosslinkable artificial nucleic acids and the hybridization chain reaction (HCR) in an attempt to improve upon the current standard method RT-qPCR, which is hampered by problems with primer design and enzymatic amplification. By introducing photocrosslinkable artificial nucleic acids to oligonucleotide probes modified with magnetic particles with a sequence complementary to that of the target miRNA and irradiating them with light, covalent bonds were formed between the target miRNA and the oligonucleotide probes. These tight covalent bonds enabled the capture of miRNA in blood, and intensive washing ensured that only the target miRNA were extracted. After extraction, two types of DNA (H1 and H2) modified with fluorescent dyes were added and the fluorescence signals were amplified by the HCR in the presence of the target miRNA bound to the photocrosslinkable artificial nucleic acids, allowing for isothermal and enzyme-free miRNA detection. The novel method is suitable for selective miRNA detection in real blood samples. Because the reaction proceeds isothermally and no specialized equipment is used for washing, this detection technology is simple and selective and suitable for application to point-of-care technology using microfluidic devices.

Stigma receptivity and flower development stage during emasculation in tomato affect artificial hybridization

ABSTRACT Determination of appropriate stages of flower emasculation and flower development when self-pollination occurs in tomato (Solanum lycopersicum L.) flowers is important to increase the degree of success of cross pollination. The experiment was conducted from July 2015 to June 2017. Seven tomato varieties (as female parents) and 1 genotype (as pollen source) were evaluated. Stages of flower emasculation (3 levels) were: 1) emasculation of immature flowers (light yellow petal) (Stage I); 2) emasculation of mature flowers (dark yellow petal, and/or petal not opened) (Stage II); and 3) emasculation of mature flowers (dark yellow petal, and/or petal partially opened) (Stage III). Complete success of cross fertilization was for the interaction of Stage II (dark yellow petal, and/or petal not opened) flower emasculation with pollination of emasculated flower after 24 h. The lowest (1.8%) percent of success of cross fertilization was at stage I (light yellow petal) flower emasculation with pollination of emasculated flower within 12 h. The low range, 1.8–5.3% of success of cross fertilization was at flower stage III (dark yellow petal, and/or petal partially opened) emasculation with no pollination of emasculated flower, indicating occurrence of an accidental self-fertilization. Stage of flower development stage I (light yellow petal) and pollination of emasculated flowers after 48 h could give the optimum percent of success of cross fertilization and avoid accidental self-pollination.

Dragon fruit farming by-products as an important source of several glycosylated flavonoids

Plants are globally used as an alternative for conventional drugs in treatment of many diseases. A significant proportion of medicinal properties of plants is addressed to antioxidant constituents as flavonoids and phenolic acids. The genus Selenicereus, known as dragon fruit, has about 15 species of epiphytic or hemiepiphytic cactus with hotspots in the tropical region of Mexico. Recently, these plants have been the focus of pharmacological studies due to the antioxidant activity of its fruits. Although many studies have investigated the biological activities of fruits, few studies investigated the chemical constituents and biological activities of cladodes. Despite the little knowledge about cladodes, it has been already observed to have higher antioxidant activities and other biological activities than the fruits. Besides this, cladodes are by-products resulting from the year-round pruning. Another important point about studies involving dragon fruit is that none of them identify the variety that is being used. As it is a commercial plant, it has many varieties created by artificial selection and hybridization such as many other food plants. In this study we found that varieties from the same species showed quantitative and qualitative differences in the metabolite profile using LC-MS. Metabolite profile from Cerrado (Selenicereus setaceus) was closer to Branca (Selenicereus undatus) than Thick King (S. setaceus), as well as Golden (S. undatus) was closer to Thick King than Branca. These results show that it is essential to identify varieties that are being used in the studies, whereas studies that attempt to replicate the experiments or use these plants for phytopreparations are prone to mislead.

Flowering Mechanism in Kodo Millet (Paspalum scrobiculatum)

Since kodo millet is a self-pollinated plant, it is essential to understand the factors that influence the length of the flowering period, pollination behaviour, and seed set in order to improve breeding programme effectiveness and yield stability while also boosting productivity. Kodo millet flowers remain closed because they are cleistogamous in nature. They have tiny florets. Emasculation and artificial hybridization are challenging because pollen is less readily available. There are also only a few sources of information. To get around this, the current inquiry was started. It aims to gather fundamental data from a variety of sources of literature, and then, with the use of fieldwork this text was prepared.

Novel molecular markers for Taxodium breeding from the chloroplast genomes of four artificial Taxodium hybrids.

Taxodium "Zhongshanshan" are a group of intraspecific Taxodium hybrids with superparental dominance and high ecological and economic value in southern China. Identifying the parentage of hybrids, especially the male parent, is critically important for genetic studies. However, the large nuclear genomes of members of the genus Taxodium pose a major challenge for the development of molecular markers. Here, we developed novel molecular markers by conducting a comparative analysis of the chloroplast genomes of four artificial Taxodium hybrids and their parents. The lengths of the whole chloroplast genome ranged from 131,942 to 132,128bp, and the total guanine (GC) content of the chloroplast genomes ranged from 34.6% to 35.81%. A total of 120 unique genes were identified, including 83 protein-coding genes, 33 transfer RNAs, and four ribosomal RNAs. There were 69-71 simple sequence repeats were detected in the four hybrids. Phylogenetic analysis revealed that these hybrids clustered with their paternal parents. Similar findings were obtained by analysis of the GC content of protein-coding genes. Molecular markers were developed using the highly variable regions of the chloroplast genomes, and polymerase chain reaction (PCR) assays revealed that these markers were effective for identifying the male parents of these hybrids. Our findings indicate for the first time that the chloroplast genomes of Taxodium are paternally inherited. Generally, these molecular markers could facilitate breeding and genetic studies of Taxodium.

Hybridizing Ti3C2Tx Layers with Layered Double Hydroxide Nanosheets at the Molecular Level: A Smart Electrode Material for H2O2 Monitoring in Cancer Cells.

Vertically stacked artificial 2D superlattice hybrids fabricated through molecular-level hybridization in a controlled fashion play a vital role in scientific and technological fields, but developing an alternate assembly of 2D atomic layers with strong electrostatic interactions could be much more challenging. In this study, we have constructed an alternately stacked self-assembled superlattice composite through integration of CuMgAl layered double hydroxide (LDH) nanosheets having positive charge with negatively charged Ti3C2Tx layers using well-controlled liquid-phase co-feeding protocol and electrostatic attraction and investigated its electrochemical performance in sensing early cancer biomarkers, i.e., hydrogen peroxide (H2O2). The molecular-level CuMgAl LDH/Ti3C2Tx superlattice self-assembly possesses superb conductivity and electrocatalytic properties, which are significant for obtaining a high electrochemical sensing aptitude. Electron penetration in Ti3C2Tx layers and rapid ion diffusion along 2D galleries have shortened the diffusion path and enhanced the charge transferring efficacy. The electrode modified with the CuMgAl LDH/Ti3C2Tx superlattice has demonstrated admirable electrocatalytic abilities in H2O2 detection with a wide linear concentration range and low real-time limit of detection (LOD) of 0.1 nM with signal/noise ratio (S/N) = 3. Practically, an electrochemical sensing podium based on the CuMgAl LDH/Ti3C2Tx superlattice has been effectively applied in real-time in vitro tracking of H2O2 effluxes excreted from different live cancer cells and normal cells after being encouraged by stimulation. The results exhibit that molecular-level heteroassembly holds great potential in electrochemical sensors to detect promising biomarkers.

Cytogenetic, molecular, and morphological characterization of Odocoileus pandora (Merriam, 1901) (Artiodactyla, Cervidae)

The Yucatan brown brocket deer was initially described as Mazama pandora Merriam, 1901. Phylogenetic analysis of mitochondrial DNA recovered the species as sister group of the genus Odocoileus and subsequently the species was repositioned to this genus naming Odocoileus pandora (Merriam, 1901). However, there is still a lack of taxonomic consensus that could assist in nomenclature definition of the species. We aim to clarify the taxonomy of O. pandora through an integrative assessment using morphological, cytogenetic, and molecular data from recently collected specimens. Morphological characterizations identified O. pandora as a medium-sized brocket deer. The skull shows an inflated auditory bulla and a narrow zygomatic arch. Males present long, broad, spike-like antlers converging inward, marked with deep longitudinal grooves. Odocoileus pandora shows a karyotype with 2 n = 60 FN = 74. Bacterial artificial chromosome clone hybridization showed that centric and tandem fusions, and inversions are involved in karyotypical divergences between O. pandora, S. gouazoubira, M. americana, and O. virginianus. Our phylogeny based on Bayesian Inference of mitogenome recovered O. pandora as monophyletic within the subtribe Odocoileina, with Odocoileus as sister taxa. Morphological and genetic characteristics of O. pandora agrees in differencing the Yucatan brown brocket from Mazama and Odocoileus genera. Therefore, a new generic name should be indicated for this taxon.

Influence of Sucrose, Boric Acid and Calcium Chloride on in vitro Pollen Germination and Tube Elongation of Alfalfa

Background: In a genetic breeding program, understanding the viability of pollen germination and pollen tube growth is an essential factor for artificial hybridization. Currently, little is known about the influence of sucrose, boric acid concentrations and calcium chloride on pollen viability in alfalfa. This study is valuable for providing information about pollen germination requirements to support further improvement of artificial pollination and breeding programs in alfalfa. Methods: The single-factor experimental and an orthogonal design method (L16 [4]3) was used to compare the effectiveness of key factors (e.g., concentrations of sucrose, boric acid and calcium chloride) to determine the pollen vigor of Medicago varia Martin. ‘Caoyuan No.1’and M. ruthenica L. Trautv. ‘zhilixing’ and to optimize the culture medium for in vitro pollen germination. Four different varieties were chosen to compare the diurnal variation of pollen vigor. Result: The four factors that influenced pollen germination in Medicago varia Martin. ‘Caoyuan No.1’and M. ruthenica L. Trautv. ‘zhilixing’ in order of significance are as follows: sucrose greater than H3BO3 greater than CaCl2. These variables influenced pollen tube growth in the following order: sucrose greater than H3BO3 greater than CaCl2. The optimal culture medium for promoting pollen vigor of Medicago varia Martin.‘Caoyuan No.1’ was 10% sucrose, 300 mon/L H3BO3 and 100 mon/L CaCl2; that of M. ruthenica L. Trautv. ‘zhilixing’ was 10% sucrose, 200 mon/L H3BO3 and 50 mon/L CaCl2. Among several species of alfalfa, ‘Caoyuan No.1’ shows the highest pollen vigor and the daily pollen activity curves of all varieties showed a single peak type.

Molecular Identification of Several Morphologically Distinct Flowerhorn Fish (Family) Using Mitochondrial <i>COI</i> Gene Marker

Flowerhorn fish has been known as a breed of fish produced by artificial hybridization between several cichlid fish. Other ornamental cichlid fish generally known to be crossed to make flowerhorn variant includes Amphilophus citrinelus, Amphilophus labiatus, Vieja melanurus, and Amphilophus trimaculatus. Our study identified a variety of flowerhorn samples with distinct morphotypes, dubbed as Cencu (LH1CC), Kamfa (LH2KF), Thai Silk (LH3TS), Kirin (LH4KR), Parrot (LH5PR), and Vieja (LH6VJ) using mtDNA COI-based DNA barcoding. Molecular analysis and phylogenetics showed that all sample had 0% genetic divergence and conspecific with A. trimaculatus sequence. Hence, we concluded that despite having varied morphotypes, all flowerhorn samples were identified as A. trimaculatus and were a variation of flowerhorn from A. trimaculatus lineage. The findings should be used as a precaution as the fish is identified as an invasive species.

Artificial hybridization techniques in small millets-A review.

Small millets are nutri-rich, climate-resilient food and fodder crops. They include finger millet, proso millet, foxtail millet, little millet, kodo millet, browntop millet, and barnyard millet. They are self-pollinated crops and belong to the family Poaceae. Hence, to widen the genetic base, the creation of variation through artificial hybridization is a prerequisite. Floral morphology, size, and anthesis behavior cause major hindrances in recombination breeding through hybridization. Manual emasculation of florets is practically very difficult; therefore, the contact method of hybridization is widely followed. However, the success rate of obtaining true F1s is 2% to 3%. In finger millet, hot water treatment (52°C) for 3 to 5min causes temporal male sterility. Chemicals such as maleic hydrazide, gibberellic acid, and ethrel at different concentrations aid in inducing male sterility in finger millet. Partial-sterile (PS) lines developed at the Project Coordinating Unit, Small Millets, Bengaluru are also in use. The percent seed set in crosses derived from PS lines ranged from 27.4 to 49.4, with an average of 40.10%. In proso millet, little millet, and browntop millet, apart from contact method, hot water treatment, hand emasculation, and the USSR method of hybridization are also followed. A newly developed modified crossing method known as the Small Millets University of Agricultural Sciences Bengaluru (SMUASB) method in proso and little millets has a success rate of 56% to 60% in obtaining true hybrids. Hand emasculation and pollination under the greenhouse and growth chamber in foxtail millet with a success rate of 75% seed set is suggested. In barnyard millet, hot water treatment (48°C to 52°C) for 5min followed by the contact method is often practiced. Kodo millet being cleistogamous, mutation breeding is widely followed to create variation. Most commonly, hot water treatment is followed in finger millet and barnyard millet, SMUASB in proso, and little millet. Although no specific method is suitable for all small millets, it is essential to identify a trouble-free technique that produces maximum crossed seeds in all the small millets.

Molecular markers in tea plant (Camellia sinensis): Applications to evolution, genetic identification, and molecular breeding

Tea plants have a long cultivation history in the world, and the beverage (tea) made from its leaves is well known in the world. Due to the characteristics of self-incompatibility, long-term natural and artificial hybridization, tea plants have a very complex genetic background, which make the classification of tea plants unclear. Molecular marker, one type of genetic markers, has the advantages of stable inheritance, large amount of information, and high reliability. The development of molecular marker has facilitated the understanding of complex tea germplasm resources. So far, molecular markers had played important roles in the study of the origin and evolution, the preservation and identification of tea germplasms, and the excellent cultivars breeding of tea plants. However, the information is scattered, making it difficult to understand the advance of molecular markers in tea plants. In this paper, we summarized the development process and types of molecular markers in tea plants. In addition, the application advance of these molecular markers in tea plants was reviewed. Perspectives of molecular markers in tea plants were also systematically provided and discussed. The elaboration of molecular markers in this paper should help us to renew understanding of its application in tea plants.

Human agricultural activities influence the flowering time of turnip in the Qinghai-Tibet Plateau

Tibetan turnip and oilseeds are the most important vegetables cultivated in the Qinghai-Tibet Plateau. Our field observations identified a dominant early-bolting phenotype at the vegetative growth stage in the Tibetan turnip, which was possibly due to cross-pollination contamination from nearby oilseeds. We performed genetic and molecular experiments to explore the main reason for early bolting. We first analyzed gene expression and genomic sequence variation of turnip and oilseed BraFLC2, a gene that acts as a key repressor of flowering in turnip in a dosage-dependent manner. We found that the differences in flowering time and life habits between turnip and oilseeds were closely correlated with the genetic variations in BraFLC2. We further identified that the early-bolting turnip was the hybrid between turnip and oilseeds by selecting BraFLC2 as a testing gene. Furthermore, using an artificial hybridization experiment, we found that the heterozygote and low levels of BraFLC2 expression promoted early bolting in hybrid plants. These findings indicate that early-bolting in turnip is caused by cross-pollination contamination from oilseeds under human agricultural activities. We propose a strategy of strict seed screening, cultivation isolation and turnip breeding to ensure high quality and yield.

MALDI-TOF: A new tool for the identification of Schistosoma cercariae and detection of hybrids.

Schistosomiasis is a neglected water-born parasitic disease caused by Schistosoma affecting more than 200 million people. Introgressive hybridization is common among these parasites and raises issues concerning their zoonotic transmission. Morphological identification of Schistosoma cercariae is difficult and does not permit hybrids detection. Our objective was to assess the performance of MALDI-TOF (Matrix Assistated Laser Desorption-Ionization-Time Of Flight) mass spectrometry for the specific identification of cercariae in human and non-human Schistosoma and for the detection of hybridization between S. bovis and S. haematobium. Spectra were collected from laboratory reared molluscs infested with strains of S. haematobium, S. mansoni, S. bovis, S. rodhaini and S. bovis x S. haematobium natural (Corsican hybrid) and artificial hybrids. Cluster analysis showed a clear separation between S. haematobium, S. bovis, S. mansoni and S. rodhaini. Corsican hybrids are classified with those of the parental strain of S. haematobium whereas other hybrids formed a distinct cluster. In blind test analysis the developed MALDI-TOF spectral database permits identification of Schistosoma cercariae with high accuracy (94%) and good specificity (S. bovis: 99.59%, S. haematobium 99.56%, S. mansoni and S. rodhaini: 100%). Most misidentifications were between S. haematobium and the Corsican hybrids. The use of machine learning permits to improve the discrimination between these last two taxa, with accuracy, F1 score and Sensitivity/Specificity > 97%. In multivariate analysis the factors associated with obtaining a valid identification score (> 1.7) were absence of ethanol preservation (p < 0.001) and a number of 2-3 cercariae deposited per well (p < 0.001). Also, spectra acquired from S. mansoni cercariae are more likely to obtain a valid identification score than those acquired from S. haematobium (p<0.001). MALDI-TOF is a reliable technique for high-throughput identification of Schistosoma cercariae of medical and veterinary importance and could be useful for field survey in endemic areas.

Comparative Analysis of Phenotypic and Molecular Data on Response to Main Pear Diseases and Pest Attack in a Germplasm Collection

The pear is an important fruit tree in temperate areas, but due to its sensitivity, fruit yield and quality are often affected by disease and pest attacks. Pear genotypes from a germplasm collection comprising 13 Pyrus species, 17 Romanian varieties, and 50 non-Romanian varieties from a worldwide assortment were investigated in this study. Throughout four years, response to attack of the principal pathogens and pests was investigated phenotypically under natural conditions of infection and infestation. SSR markers were used to analyze the genetic diversity of the genotypes. A standardized method for the evaluation of responses to biotic stressors was proposed, which highlighted significant differences between genotypes. The species and varieties with the lowest degrees of attack (DA%), calculated based on the frequency and intensity of attack, were identified for pear scab (Venturia pyrina), septoria (Septoria pyricola), fire blight (Erwinia amylovora), and psyllids (Psylla sp.). These accessions could provide valuable sources of genes of interest to develop resistant varieties in new pear breeding programs. By combining phenotypic and molecular analyses, significant information was obtained that can be exploited to generate high variability for selection through artificial hybridization by harnessing accessions with complementary molecular fingerprints and high genetic distances.

Master-Key Regulators of Sex Determination in Fish and Other Vertebrates-A Review.

In vertebrates, mainly single genes with an allele ratio of 1:1 trigger sex-determination (SD), leading to initial equal sex-ratios. Such genes are designated master-key regulators (MKRs) and are frequently associated with DNA structural variations, such as copy-number variation and null-alleles. Most MKR knowledge comes from fish, especially cichlids, which serve as a genetic model for SD. We list 14 MKRs, of which dmrt1 has been identified in taxonomically distant species such as birds and fish. The identification of MKRs with known involvement in SD, such as amh and fshr, indicates that a common network drives SD. We illustrate a network that affects estrogen/androgen equilibrium, suggesting that structural variation may exert over-expression of the gene and thus form an MKR. However, the reason why certain factors constitute MKRs, whereas others do not is unclear. The limited number of conserved MKRs suggests that their heterologous sequences could be used as targets in future searches for MKRs of additional species. Sex-specific mortality, sex reversal, the role of temperature in SD, and multigenic SD are examined, claiming that these phenomena are often consequences of artificial hybridization. We discuss the essentiality of taxonomic authentication of species to validate purebred origin before MKR searches.

Prediction of fracture density in a gas reservoir using robust computational approaches

One of the challenges that reservoir engineers, drilling engineers, and geoscientists face in the oil and gas industry is determining the fracture density (FVDC) of reservoir rock. This critical parameter is valuable because its presence in oil and gas reservoirs boosts productivity and is pivotal for reservoir management, operation, and ultimately energy management. This valuable parameter is determined by some expensive operations such as FMI logs and core analysis techniques. As a result, this paper attempts to predict this important parameter using petrophysics logs routinely collected at oil and gas wells and by applying four robust computational algorithms and artificial intelligence hybrids. A total of 6067 data points were collected from three gas wells (#W1, #W2, and #W3) in one gas reservoir in Southwest Asia. Following feature selection, the input variables include spectral gamma ray (SGR); sonic porosity (PHIS); potassium (POTA); photoelectric absorption factor (PEF); neutron porosity (NPHI); sonic transition time (DT); bulk density (RHOB); and corrected gamma ray (CGR). In this study, four hybrids of two networks were used, including least squares support vector machine (LSSVM) and multi-layer perceptron (MLP) with two optimizers particle swarm optimizer (PSO) and genetic algorithm (GA). Four robust hybrid machine learning models were applied, and these are LSSVM-PSO/GA and MLP-PSO/GA, which had not previously used for prediction of FVDC. In addition, the k-fold cross validation method with k equal to 8 was used in this article. When the performance accuracy of the hybrid algorithms for the FVDC prediction is compared, the revealed result is LSSVM-PSO &amp;gt; LSSVM-GA &amp;gt; MLP-PSO &amp;gt; MLP-GA. The study revealed that the best algorithm for predicting FVDC among the four algorithms is LSSVM-PSO (for total dataset RMSE = 0.0463 1/m; R2 = 0.9995). This algorithm has several advantages, including: 1) lower adjustment parameters, 2) high search efficiency, 3) fast convergence speed, 4) increased global search capability, and 5) preventing the local optimum from falling. When compared to other models, this model has the lowest error.

Speciation of &lt;i&gt;Viola albida&lt;/i&gt; var. &lt;i&gt;takahashii&lt;/i&gt; based on both artificial and natural hybridization between &lt;i&gt;V. albida&lt;/i&gt; var. &lt;i&gt;albida&lt;/i&gt; and &lt;i&gt;V. albida&lt;/i&gt; var. &lt;i&gt;chaerophylloides&lt;/i&gt;

The study aims are to examine the characteristics of artificial and natural hybrids between &lt;i&gt;Viola albida&lt;/i&gt; var. &lt;i&gt;albida&lt;/i&gt; (= &lt;i&gt;albida&lt;/i&gt;, from below) and &lt;i&gt;V. albida&lt;/i&gt; var. &lt;i&gt;chaerophylloides&lt;/i&gt; (= &lt;i&gt;chaerophylloides&lt;/i&gt;, from below), and to confirm if hybrids could be fertile and make populations in their native habitats. The 1st filial (= F&lt;sub&gt;1&lt;/sub&gt;, from below) leaf shape produced by artificial crossing between &lt;i&gt;albida&lt;/i&gt; and &lt;i&gt;chaerophylloides&lt;/i&gt; was the same as that of &lt;i&gt;V. albida&lt;/i&gt; var. &lt;i&gt;takahashii&lt;/i&gt; (= &lt;i&gt;takahashii&lt;/i&gt;, from below), and F&lt;sub&gt;1&lt;/sub&gt; bore also both chasmogamous and cleistogamous flowers. F&lt;sub&gt;1&lt;/sub&gt; seed number was 9.6 per cleistogamous pods, which was remarkably less than the average of 38.2 for &lt;i&gt;albida&lt;/i&gt; and &lt;i&gt;chaerophylloides&lt;/i&gt;, but the germination rate was all similar. The leaf type of self-crossed 2nd offsprings (= F&lt;sub&gt;2&lt;/sub&gt;, from below) showed all leaf types found in the &lt;i&gt;Viola albida&lt;/i&gt; complex, but the ratio of &lt;i&gt;chaerophylloides&lt;/i&gt; leaf type was relatively low. Individuals whose F&lt;sub&gt;2&lt;/sub&gt; leaf type was restored to &lt;i&gt;albida&lt;/i&gt; produced an average of 31.4 seeds per capsule, meaning that fertility was restored. On the other hand, individuals of F&lt;sub&gt;2&lt;/sub&gt; &lt;i&gt;takahashii&lt;/i&gt; leaf type come to fruition a low average of 10.4 seeds per capsule, which is similar to that of &lt;i&gt;takahashii&lt;/i&gt;. The results of crossbreeding experiment, where is their native habitats, were similar to that of laboratory. Both &lt;i&gt;albida&lt;/i&gt; and &lt;i&gt;chaerophylloids&lt;/i&gt; in Mt. Bulmyeong distribute extensively, but &lt;i&gt;takahashii&lt;/i&gt; make a small population only in places where &lt;i&gt;albida&lt;/i&gt; and &lt;i&gt;chaerophylloides&lt;/i&gt; grow together. Summarizing the above results is suggesting that the speciation of &lt;i&gt;takahashii&lt;/i&gt; was done by hybrid between &lt;i&gt;albida&lt;/i&gt; and &lt;i&gt;chaerophylloides&lt;/i&gt;, and these have been maintained with relatively small population by cleistogamous capsules.

Meiosis and male fertility in F1 interspecific hybrids (Passiflora vitifolia vs. Passiflora hatschbachii)

Interspecific hybrids can be studied using methodologies in which the male gamete with high reproduction potential, viability, and fertility is prioritized. Passiflora species, with lush, showy, and exotic colors, have great potential for the ornamental plant market. In addition, artificial Passiflora hybrids were developed without many difficulties because of weak reproductive barriers. Thus, meiotic and post-meiotic behaviors were analyzed with 2% acetic carmine staining. Confirmation of interspecific hybridization was performed using SSR markers and GISH technique was used to detect genomic differentiation. The pollen viability of the parental and hybrids genotypes was tested using Alexander`s solution, fluorescein diacetate and in vitro germination tests were performed using culture medium. The meiotic behavior was regular and displayed haploid number n = 9 with nine bivalent (II) chromosomal, and pairing in 90% of the cells in diakinesis. There was a significant difference (p < 0.05) in terminal and interstitial chiasma frequencies. Meiotic irregularities observed were as follows: early and/or delayed chromosomes, disorientation of spindle fibers, transverse spindles, tripolar spindles, and asynchrony; and consequently irregular post-meiotic products were observed: monads, dyads, triads, and polyads. GISH was used in the interspecific hybrids and pairing between homeologous chromosomes, and bivalent and tetravalent formation were observed. From this study, we could conclude that hybrid genotypes are fertile and pollen grains are viable and can be used in breeding programs.

The taxonomic relevance of Naphthoquinones in tropical pitcher plants (Nepenthes L., Nepenthaceae)

The distribution of the naphthoquinones ramentaceone and plumbagin was studied among 50 taxa of the genus Nepenthes. Naphthoquinone patterns support classifications based on homology of plastid and/or nuclear genes to some extent, with plumbagin predominant in sections Nepenthes, Urceolatae, Tentaculatae, and Regiae, ramentaceone predominant in sections Insignes and Villosae, and both isomers present without clear predominance in sections Pyrophytae and Montanae. Only 9 of 96 studied species contained both isomers in the same plant. Naphthoquinone data from artificial hybrids of known parentage allowed conclusions on the biosynthesis of these compounds and the heredity of the respective enzymatic steps.