Artificial Hybrids Research Articles

Interspecific hybridisation among diverse Saccharomyces species: A combined biotechnological solution for low-temperature and nitrogen-limited wine fermentations

Lack of the prezygotic barrier in the Saccharomyces genus facilitates the construction of artificial interspecific hybrids among different Saccharomyces species. Hybrids that maintain the interesting features of parental strains have been applied in industry for many beneficial purposes. Two of the most important problems faced by wine makers is nitrogen deficiency in grape must and low-temperature fermentation. In our study, hybrids were constructed by using selected low nitrogen-demanding cryotolerant S. eubayanus, S. uvarum strains and S. cerevisiae. The fermentation capacity of the hybrid strains was tested under four conditions by combining two temperatures, 12 °C and 28 °C, and two nitrogen concentrations, 60 mg/L and 300 mg/L. The hybrid strains obtained combined characters of both parental strains and conferred better fermentation rates under low-temperature or low-nitrogen conditions. The hybrid strains also produced larger amounts of acetate esters and higher alcohols, which increase aroma intensity and complexity in wine. Nitrogen sources were more rapidly consumed by the hybrid strains, which allows greater competition ability under nitrogen-deficiency conditions. Therefore, the interspecific hybridisation between low nitrogen-demanding cryotolerant strains and S. cerevisiae is a potential solution for low-temperature or low-nitrogen fermentations.

Variation of Pollination Rate on Eucalyptus grandis and E. tereticornis

The most widely used clones were all breed by artificial hybrids steps in China, therefore it is important to research on pollination rate. Three individual trees of E. grandis and E. tereticornis were selected as female while the pollen of hybrid clone DH32-29, E. grandis, E. pellita, E. tereticornis and E. urophylla were collected as male. The results indicated that E. grandis family 4 always had higher pollination rate with different male pollen than other E. grandis families. Family 116 had higher pollination rate with DH32-29 and E. urophylla than family 41 while family 41 had higher pollination rate with E. grandis and E. tereticornis than family 116. Though different families had different pollination rate, the studied E. grandis families all had higher pollination rate (above 75%) with different male pollen. E. tereticornis family 243-1 always had higher pollination rate (nearly 100%) with different male pollen than other E. tereticornis families while E. tereticornis family 238-2 always had lower pollination rate (nearly 60%) with different male pollen than other E. tereticornis families. All the male pollen had similar pollination rate with family 238-1 and 243-1. E. grandis pollen had higher pollination rate with family 238-2 than other male pollens.

Frequent intra- and inter-species introgression shapes the landscape of genetic variation in bread wheat

BackgroundBread wheat is one of the most important and broadly studied crops. However, due to the complexity of its genome and incomplete genome collection of wild populations, the bread wheat genome landscape and domestication history remain elusive.ResultsBy investigating the whole-genome resequencing data of 93 accessions from worldwide populations of bread wheat and its diploid and tetraploid progenitors, together with 90 published exome-capture data, we find that the B subgenome has more variations than A and D subgenomes, including SNPs and deletions. Population genetics analyses support a monophyletic origin of domesticated wheat from wild emmer in northern Levant, with substantial introgressed genomic fragments from southern Levant. Southern Levant contributes more than 676 Mb in AB subgenomes and enriched in the pericentromeric regions. The AB subgenome introgression happens at the early stage of wheat speciation and partially contributes to their greater genetic diversity. Furthermore, we detect massive alien introgressions that originated from distant species through natural and artificial hybridizations, resulting in the reintroduction of ~ 709 Mb and ~ 1577 Mb sequences into bread wheat landraces and varieties, respectively. A large fraction of these intra- and inter-introgression fragments are associated with quantitative trait loci of important traits, and selection events are also identified.ConclusionWe reveal the significance of multiple introgressions from distant wild populations and alien species in shaping the genetic components of bread wheat, and provide important resources and new perspectives for future wheat breeding.

Fertilization, survival and growth of hybrids between Crassostrea gigas and Crassostrea sikamea

Crossbreeding is a powerful tool for animal breeding and genetic improvement in aquaculture. In this work, artificial interspecific hybridization was carried out and three crosses were successfully produced, namely Crassostrea gigas (GG), C. sikamea (SS) and C. sikamea ♀ × C. gigas ♂ (SG), although C. gigas ♀ × C. sikamea ♂ formed nonviable hybrid offspring. The fertilization and hatching success of the SG cross was at an acceptable level compared with that of the intraspecific crosses. At the larval stage, the growth rate of the SG cross corresponded to that of the SS cross, but was significantly lower than the GG cross, and the survival rate of the SG cross did not differ from that of either parental cross. During the spat stage, the single-parent heterosis value of the growth rate for the SG cross ranged from 8.85 to 24.43%. Considering survival rates, notable mid-parent heterosis (27.16–76.00%) and clear single-parent heterosis (30.53–73.28%) were observed, though no significant differences were observed among the three crosses. Our results clearly demonstrate that the production performance of the hybrid SG cross is comparable to that of the maternal parental SS cross. The high survival advantage and single-parent heterosis for the growth trait observed in the SG cross provides a promising method for the genetic improvement of oysters.

Expression Effects of CHI and CHS Genes and Colchicine Treatment in Yellow Flowered Cyclamen: a Review

Nowadays, the field of entirely artificial hybrids raises ethical problems in the animal world and to a lesser amount in plants. Throughout the years, yellow Cyclamen has been particularly important for both breeders and passionate growers as being a peculiar color for this species. The possibility to artificially induce hybrids between species that can never normally cross it’s now achievable. This paper describes the possibility of obtaining high ornamental yellow flowered cyclamen, through chromosome doubling. The pollen and seed sterility can be overcome by doubling the chromosomes. In this sense, there are two full sets from each parent, resulting in a fertile hybrid, by introducing the in vitro culture into colchicine supplemented medium.

Fullerene-Directed Synthesis of Flowerlike Cu3(PO4)2 Crystals for Efficient Photocatalytic Degradation of Dyes.

Biomineralization is a typical methodology developed by nature to produce calcium-based materials. A method mimicking this process has nowadays become popular for the preparation of artificial organic-inorganic hybrids. Here, Cu3(PO4)2 crystals with a flowerlike morphology have been prepared using water-soluble derivatives of fullerene C60 as templates. In a typical system, flowerlike crystals of Cu3(PO4)2 (denoted FLCs-Cu) were obtained by simply dropping an aqueous solution of CuSO4 into phosphate-buffered saline (PBS) containing a highly water-soluble multiadduct of C60 (fullerenol). The best condition for the preparation of FLCs-Cu appeared at 0.20 mg·mL-1 fullerenol and 0.10 mol·L-1 PBS. During the formation of FLCs-Cu, fullerenol acts as a template and its content in FLCs-Cu is trace (less than 5% by atom) as confirmed by scanning electron microscopy mapping and thermogravimetric analysis. This feature makes fullerenol reusable, and the FLCs-Cu can be prepared repeatedly using the same fullerenol aqueous solution at least 10 times without a noticeable change in the morphology. The N2 adsorption/desorption isotherm showed that the doping of fullerenol increased the specific surface area of the Cu3(PO4)2 crystal. When fullerenol was replaced by C60 monoadducts that are cofunctionalized with a pyrrolidine cation and oligo(poly(ethylene oxide)) chains, FLCs-Cu can form as well, indicating that the strategy of using water-soluble C60 derivative as a template to get FLCs-Cu is universal. As a typical example of practical applications, the photocatalytic activity of the FLCs-Cu was investigated toward the degradation of dyes including rhodamine B and rhodamine 6G. In both cases, efficient photodegradation has been confirmed.

Inheritance of specific secondary volatile metabolites in buds of white birch Betula pendula and Betula pubescens hybrids

Despite the differences in ploidy and in the timing of flowering, two species of white birch, Betula pendula and Betula pubescens often form viable hybrids in places of their joint growth. Recognition of such hybrids by their morphological features is very difficult or impossible. On the other hand, it could be assumed that substantial differences can be found in the secondary metabolites whose composition is determined mainly by genetic factors. However, the inheritability of biosynthesis of secondary birch metabolites is unknown. We investigated the bud volatile organic compounds (VOCs) of the artificial hybrids of these birches and compared them with specific metabolites of pure parent species. The bud VOCs were determined by a combination of head-space microextraction with gas chromatography-mass spectrometry. As the result, we found that: (a) hybrids clearly show dominant inheritance along the maternal line and (b) the buds of hybrid plants have characteristic features of VOCs composition, which allows for definitive conclusions about hybrid origins in some cases.

Transcriptome profiling of the fertile parent and sterile hybrid in tea plant flower buds

BackgroundThe tea plant is a crucial economic crop. The floral organ development consumes a large amount of nutrients, which affects the leaf yield. To understand the mechanism by which the tea plant produces sterile floral buds, we obtained a sterile tea plant by artificial hybridization. RNA-sequencing based transcriptome analysis was implemented in three samples to determine the differentially expressed genes (DEGs) related to flower development.ResultsIn this study, a total of 1991 DEGs were identified; 1057 genes were up-regulated and 934 genes were down-regulated in sterile hybrid floral buds. These were mainly distributed in the regulation of biological and metabolic processes. Significantly, auxin biosynthesis genes YUCCA, AUX1 and PIN were dramatically down-regulated, and ARF gene was up-regulated in the sterile hybrid floral buds, and flower development-related genes AP1, AP2 and SPL were changed. A total of 12 energy transfer-related genes were significantly decreased. Furthermore, the expression of 11 transcription factor genes was significantly different.ConclusionThe transcriptome analysis suggested that the production of sterile floral buds is a complex bioprocess, and that low auxin-related gene levels result in the formation of sterile floral buds in the tea plant.

A network meta‐analysis of threats to South American fish biodiversity

AbstractWhile environmental alterations have made Homo sapiens the hyperkeystone species of the globe, biotic homogenization initiated a new era, the “Homogenocene.” Still, some terrestrial and aquatic ecosystems in South America are considered pristine and wild, which can lead to a general faith that economic progress is consistent with conservation strategies, even without scientific support. We compiled anthropogenic threats to fish biodiversity in a hierarchical meta‐analysis, along with an evidence synthesis of threats related to biological invasions, based on peer‐reviewed research with the aim to represent the actual conservation status of the South American ichthyofauna. We highlighted human‐related threats and synergistic effects of biological invasions, climate change, environmental alterations (e.g., pollution, aquaculture and damming) and fisheries. Considering measures that reinforce novel alien fish (e.g., artificial hybrids or genetically modified) introductions, it became clear why an eventual increase in local or regional species richness is not always beneficial to aquaculture, biodiversity, human well‐being or nature. In fact, citizens in all societal roles, including scientists, should revise their concepts about threats to fish biodiversity. Environmental policies require more than taxonomic diagnostics to achieve conservation goals under an incompatible scenario of a multiplying number of fish species and biotic homogenization. We advocate for countries in South America using science‐based strategies useful to maintain their social and economic growth along with their “remaining nature.” We live a crucial moment when the government overlooks threats to biodiversity and uses agribusiness as the most acceptable manner of fuelling the economy.

Influence of Pollen Germination Capacity on a Successful Artificial Hybridization in Cyclamen sp

The artificial hybridization is one of the most important methods to create variability in breeding programs. The success of artificial hybridization very often depends on the fertility of pollen grains which require a minimum 30% germination level. The aim of the present study was to identify the correlation between the level of pollen grain fertility and success of hybridization in several cyclamen cultivars. There were taken under study seven cultivars of Cyclamen sp. very different from phenotypic point of view (maxi, midi, mini). In the first step it was determinated the germination capacity of pollen grains trough viability and germinability percentage and the correlation between these two determinations. The results show a higher ratio of viability then germinability in all cultivars. The best results of artificial hybridization were registered in hybrid combinations in which there were used cultivars with the highest percentage of pollen fertility. Out of seven cyclamen cultivars tested in 18 hybrid combinations, three cultivars showed the highest level of fertility when used as male genitor (Curly White; Curly Magenta Picotee and Allure Salmon Flamed)for a further study on phenol biodegradation especially areas with phenol contamination containing some heavy metals.

Encapsulation of zinc phthalocyanine into bovine serum albumin aggregates

Artificial hybridization of molecules with proteins is beneficial for biomedical applications. Herein, we describe a novel method for encapsulation of zinc phthalocyanine (ZnPc) aggregates into bovine serum albumin (BSA) aggregates, but not monomeric BSA. This property is potentially useful for not only photodynamic or photothermal therapy but also development of a novel delivery system for hydrophobic drug molecules.

Artificial crosses and hybridization frequency in five-needle pines

Artificial crosses and hybridization frequency in five-needle pines

Micropropagation of two near threatened orchid. Part 2: Phalaenopsis amabilis Blume var. Grandiflora

Phalaenopsis is one of the most popular orchids in the world, through the development of many artificial hybrids. In this research, a reliable and efficient protocol is presented for in vitro proliferation of Phalaenopsis amabilis Blume cv. Grandiflora. Protocorm-like bodies (PLBs) were cultured on Murashige and Skoog (MS) medium containing different concentrations of kinetin (Kn; 0.00, 0.50, 1.00, 2.00 and 3.00 mg l-1) and indole-3-butyric acid (IBA; 0.00, 0.10, 0.20, 0.50 and 1.00 mg l-1), either individually or in combination and activated charcoal (AC; 0.00, 0.50 and 1.00 g l-1). A combination of 0.20 mg l-1 IBA and 2.00 mg l-1 Kn on medium containing 1.00 g l-1 AC was found to be suitable for maximum leaf number (6.16±0.503 per explant). The highest rooting frequency with 7.13±0.153 roots per explant was achieved on medium enriched with 0.50 mg l-1 IBA and 0.50 mg l-1 Kn on medium containing 1.00 g l-1 AC. The largest number of callus (9.10±0.611) was induced on explants cultured in medium containing 0.20 mg l-1 IBA and 0.50 mg l-1 Kn on medium without AC. The plantlets were successfully acclimatized in the greenhouse with a survival rate of 95% exhibiting normal developmental patterns.

Cloning in sturgeon hybrids (Acipenseridae): experimental reproduction of the first stages of reticular speciation in fish and the method of obtaining all-female offspring

Cloning in sturgeon hybrids (Acipenseridae): experimental reproduction of the first stages of reticular speciation in fish and the method of obtaining all-female offspring

Natural hybridization – recombination – an ever-ongoing process

Exemplified by studies of the SE Asian genus Cryptocoryne (Araceae) we provide evidence that: 1) interspecific hybridization is an everongoing process, and introgression and gene exchange takes place whenever physically possible throughout the region; 2) artificial hybridization experiments confirm that wide crosses are possible in a large number of cases; 3) rivers and streams provide numerous, diverse habitats for Cryptocoryne diaspores to settle in; 4) the changes in habitats caused by recurrent glaciations resulting in numerous splitting and merging of populations facilitates hybridization and segregation of subsequent generations; 5) hybridization is a major driving element in speciation; 6) populations are the units and stepping stones in evolution – not the species.

‘SCS425 Luiza’: new apple cultivar with medium chilling requirement and resistant to glomerella leaf spot (colletotrichum spp.)

Abstract Apple is one of the main agribusiness products of temperate-zone fruits in Southern Brazil. More than 90% of apple production is obtained from only two apple cultivars – Gala and Fuji and their mutations. These apple varieties are insufficiently adapted to the regional climate and ‘Gala’ and its mutations are also susceptible to glomerella leaf spot – GLS, currently the main apple disease in Brazil. ‘SCS425 Luiza’ cultivar was developed by Epagri / Estação Experimental Caçador, aiming to offer to the production chain an early apple variety better adapted to the environmental conditions of Southern Brazil and resistant to GLS. ‘SCS425 Luiza’ cultivar was obtained by artificial hybridization carried out in 2001 using the cultivars Imperatriz and Cripps Pink as parents. ‘SCS425 Luiza’ has lower chilling requirement compared to ‘Galaxy’, higher flowering precocity and yield potential at least equivalent to ‘Galaxy’. It produces fruits with skin finish, flavor and flesh texture adequate for the Brazilian market and storability similar to ‘Galaxy’ apples when harvested at the same maturity.

Inheritance of powdery mildew resistance in Aurotica’s introgressive lines

Aim. Frequency of alien chromatin inheritance in hybrids from crosses of common wheat and introgressive lines determines whether transfer of alien chromatin controlling desirable trait into common wheat genome would be successful. The paper presents results of introgressive lines assessment for frequency of transfer of alien dominant trait of powdery mildew resistance to their progeny in the crossing with recurrent genotype Aurora, which was a recipient cultivar in the development of these lines. Methods. Artificial hybridization of introgressive lines with common wheat, visual assessment of cross components and hybrids F1 and F2 for powdery mildew resistance. Determination of chromosome numbers and chromosome configurations in meiosis M1 of F1 plants. Results. Among F2 plants, from the crossing of resistant to powdery mildew introgressive lines of Aurotica and susceptible cultivar Aurora excess of susceptible plants was observed. In order to explain distortion of ratio susceptible : resistant plants in comparison with expected for monogenic segregation, we propose the determined fact of absence in meiosis M1 of MPC of bivalent chromosome conjugation, which results in formation of aneuploid gametes and zygotes with reduced viability. As the third parameter, the one that can influence the mentioned ratio, we propose d parameter, which quantitatively expresses excess of gametes without alien chromatin controlling resistance to powdery mildew. Conclusion. Model of inheritance, which best explains experimental data of F2 plants segregation for resistant and susceptible if the trait is controlled by one dominant gene, takes into account the following conditions for calculation of probabilities of resistant or susceptible plant formation: all female and only euploid male gametes function, nullisomic zygotes are not viable, during meiosis elimination of meiosis products with alien chromatin occurs with parameter d = 0,11–0,12.Received 11.06.2018

Canopy Temperature and Chlorophyll Content are Effective Measures of Drought Stress Tolerance in Durum Wheat

Durum wheat (Triticum durum L.) is used for the preparation of multiple food products, including pasta and bread. Its production is restricted due to diverse environmental stresses i.e. drought and heat stress. Here, comparative analysis of durum wheat varieties was done by studying canopy temperature depression (CTD) and chlorophyll content (CHL), yield and yield contributing traits to evaluate their performance under stress and low stress conditions. Twelve durum wheat genotypes were studied under stressful and low-stress conditions in Gachsaran region of Iran. CTD and CHL were measured at two stages, from the emergence of fifty percent of inflorescence (ZGS 54) to watery ripe stage (ZGS 71). According to stress tolerance index (STI), mean productivity (MP) and geometric mean productivity (GMP) indices, genotype G10 exhibited the most, while genotype G6, the least relative tolerance, respectively. Based on MP and GMP, genotype G10 was found to be drought tolerant, while genotype G2 displayed the lowest amount of MP and GMP. Therefore these genotypes are recommended to be used as genitors in artificial hybridization for improvement of drought tolerance in other cultivars. All indices had high correlation with grain yield under stress and non-stress condition, indicating more suitability of these indices for selection of resistant genotype. Results of the present study showed that among drought tolerance indices, harmonic mean (HM), GMP, CTD and modified STI index (K2STI) can be used as the most suitable indicators for screening drought tolerant cultivars.

Repetitive DNA in the Architecture, Repatterning, and Diversification of the Genome of Aegilops speltoides Tausch (Poaceae, Triticeae).

The genome’s adaptability to environmental changes, especially during rapid climatic fluctuations, underlies the existence and evolution of species. In the wild, genetic and epigenetic genomic changes are accompanied by significant alterations in the complex nuclear repetitive DNA fraction. Current intraspecific polymorphism of repetitive DNA is closely related to ongoing chromosomal rearrangements, which typically result from erroneous DNA repair and recombination. In this study, we addressed tandem repeat patterns and interaction/reshuffling both in pollen mother cell (PMC) development and somatogenesis in the wild diploid cereal Aegilops speltoides, with a focus on genome repatterning and stabilization. Individual contrasting genotypes were investigated using the fluorescent in situ hybridization (FISH) approach by applying correlative fluorescence and electron microscopy. Species-specific Spelt1 and tribe-specific Spelt52 tandem repeats were used as the markers for monitoring somatic and meiotic chromosomal interactions and dynamics in somatic interphase nuclei. We found that, the number of tandem repeat clusters in nuclei is usually lower than the number on chromosomes due to the associations of clusters of the same type in common blocks. In addition, tightly associated Spelt1–Spelt52 clusters were revealed in different genotypes. The frequencies of nonhomologous/ectopic associations between tandem repeat clusters were revealed in a genotype-/population-specific manner. An increase in the number of tandem repeat clusters in the genome causes an increase in the frequencies of their associations. The distal/terminal regions of homologous chromosomes are separated in nuclear space, and nonhomologous chromosomes are often involved in somatic recombination as seen by frequently formed interchromosomal chromatin bridges. In both microgametogenesis and somatogenesis, inter- and intrachromosomal associations are likely to lead to DNA breaks during chromosome disjunction in the anaphase stage. Uncondensed/improperly packed DNA fibers, mainly in heterochromatic regions, were revealed in both the meiotic and somatic prophases that might be a result of broken associations. Altogether, the data obtained showed that intraorganismal dynamics of repetitive DNA under the conditions of natural out-crossing and artificial intraspecific hybridization mirrors the structural plasticity of the Ae. speltoides genome, which is interlinked with genetic diversity through the species distribution area in contrasting ecogeographical environments in and around the Fertile Crescent.

STMS (sequence tagged microsatellite site) molecular markers as a valuable tool to confirm controlled crosses in chickpea (Cicer arietinum L.) breeding programs

Chickpea (Cicer arietinum L.) is an annual, diploid and autogamous grain legume. Most breeding processes developed in this crop start with complementary crosses, but artificial hybridization is a tedious operation probably due to the injury of the pistil caused during emasculation due to the small size of the flowers. The success in pod formation after hybridization together with the possibility of testing the hybrid nature of F1 is a key point to optimize chickpea breeding. Morphological characters are not always adequate to distinguish between progeny, consequently molecular markers are needed to verify hybrid nature. In this study, we show our experience in crossing programs and the use of molecular markers to test hybridization rate in three different cases (A) obtaining advanced lines combining resistance to blight and fusarium wilt; (B) developing segregating populations for Orobanche foetida and (C) providing suitable materials to do genetic studies involving double pod mutants. A total of 2041 pollinated flowers produced 21.7, 16.8 and 8.7% of pods in each one of the three cases analyzed. Hybridization nature in F1 seeds was tested with STMS (sequence tagged microsatellite site) markers and ranged from 86 to 91% for the three cases. STMS markers were a valuable tool to detect hybrids, being simple to visualize and having a low cost. The confirmation of hybrid nature at the initial development stages of F1 plants is critical for reducing time and costs in breeding programs.