Intergeneric Hybrids Research Articles

Range extension of the Mexican-endemic killifish Profundulus chimalapensis (Cyprinodontiformes: Profundulidae), with comments on its phylogenetic placement and possible intergeneric hybridization with Tlaloc Álvarez & Carranza 1951

Recent ichthyological surveys in southern Mexico resulted in the unexpected discovery of populations of P. chimalapensis outside its distribution range, broadening its extent of occurrence to a total of three river basins (Coatzacoalcos [original], Grijalva, Ostuta) and two versants (Atlantic [original] and Pacific). The taxonomic nature of these populations was further investigated using comparative genetic data in a phylogenetic framework. Our results include the first assessment of the phylogenetic position of P. chimalapensis with respect to other Profundulus species and imply a sister-group relationship with P. oaxacae. Remarkably, our results also imply a close phylogenetic affinity of some P. chimalapensis samples with the genus Tlaloc, which we interpret as possible evidence of intergeneric hybridization, a phenomenon previously unreported in the family. If our interpretation in this regard is correct, it raises several broader evolutionary and taxonomic questions, such as the role that introgressive hybridization might be playing as a driver of speciation in profundulid fishes. From a historical biogeographic perspective, the proposed expanded geographic range could be explained by inter-basin dispersal enabled by recent or historical events (e.g., paleodrainage connections, headwaters stream capture, floodings) in the same fashion as these have been invoked to explain distribution patterns in other Middle American freshwater fishes.

Studies on Distant Hybridization Compatibility between the Azalea (Rhododendron × hybridum hort.) and the Rhododendron decorum Franch. Native to China

Rhododendron resources are abundant in China, and hybridization breeding technology is the primary method for cultivating Rhododendron varieties. In order to optimize the utilization of wild Rhododendron resources for distant hybridization, this study took three horticultural varieties of Rhododendron subgenus Tsutsusi and the Rhododendron decorum Franch. of the subgenus Hymenanthes as the research objects, and the cross-compatibility between subgenera was analyzed from the aspects of pollen tube growth and ovary and seed development. At the same time, the statistics of ovary swelling rate and fruit bearing rate, numbers of capsule seeds, 1000 seed weight of hybrid seeds, germination rate, green seedling rate, and other indexes were analyzed to comprehensively evaluate hybrid fertility. The results showed that there was obvious pre-fertilization and post-fertilization barriers existing in the hybridization of Rhododendron × hybridum hort. and R. decorum. During the growth of pollen tubes, a large amount of callus appeared, which led to the entanglement, distortion, and abnormal development of the pollen tubes; only part of the pollen tubes entered into the ovary or ovule. The pre-fertilization barriers can be overcome by early pollination and delayed pollination. According to the observation of the ovary paraffin section, 45 d after pollination, the seed was shriveled and developed abnormally. The comprehensive evaluation of hybrid fertility showed that ‘Sima’ × R. decorum was fertile, ‘Yin Taohong’ × R. decorum was a weakly fertile, and ‘Little Taohong’ × R. decorum was sterile. This study provided a scientific basis for intergeneric hybridization breeding between the subgenus Tsutsusi and the subgenus Hymenanthes.

Transcriptome analysis reveals the dynamics of gene expression during early embryonic development of hybrid groupers

Distant hybridization is widely applied in genetic improvement of aquatic animals. Although this technique should be suitable for genetic improvement of grouper, few studies related to offspring produced via distant hybridization have been reported. There we studied the gene expression dynamics of early embryonic development of groupers from self-breeding, intraspecific breeding and intergeneric hybridization. We first obtained offspring from female brown-marbled grouper (Epinephelus fuscoguttatus) and male leopard coral grouper (Plectropomus leopardus) and described the morphological characteristics of different developmental stages of embryos. We then constructed the transcriptome maps during early embryonic development of hybrid groupers. In addition, we also found that the process of MZT occurred from high blastula to early gastrula stage in the embryo of hybrid grouper and that wnt signaling pathway play an important role in dorsal-ventral axial formation during embryonic development of grouper. These results provide a foundation for the hybrid breeding of leopard coral grouper.

Transcriptome analysis reveals genetic regulation of growth diversity in F2 intergeneric hybrids of Megalobrama amblycephala and Culter alburnus

Hybridization between different genera can greatly shape the genotype and phenotype of individuals. It is possible to sporadically obtain individuals or populations with heterosis through conducting multiple rounds and stages of hybridization, backcrossing, and self-crossing. Investigating the regulatory relationship between allelic combinations from different species and specific economic traits in hybrid individuals will help us understand the genetic mechanism of heterosis. In this study, we conducted a transcriptomic analysis of 25 individuals from the F2 population obtained from the intergeneric hybridization of blunt snout bream (Megalobrama amblycephala, BSB) and topmouth culter (Culter alburnus, TC). We identified 94,897 SNPs on the subgenome BSB (originating from species BSB) and 26,372 SNPs on the subgenome TC (originating from species TC). By utilizing WGCNA to construct a co-expression network, we successfully identified 54 key genes involved in growth regulation. Of these, 8 genes from subgenome BSB show 7 positively influencing and 1 negatively influencing growth rate. Additionally, 46 genes in subgenome TC include 24 with positive and 22 with negative correlations to growth rate. Using eQTL analysis, we assessed associations between SNPs and gene expression levels for 3736 cis- and 7683 trans-regulatory events. In comparative analyses of eQTL and WGCNA, we detected 2 cis- and 16 trans-regulatory genes shared in them, indicating their potential regulatory network in growth diversity in the hybrid. These results help us understand the complex regulatory network of growth traits in intergeneric hybrids. It represents a significant advancement in molecular-assisted breeding, offering valuable insights for developing effective hybrid breeding strategies and achieving heterosis in populations or individuals.

Assessment of antioxidant, antidiabetic, and antimicrobial properties of hybrid mushroom strains derived through intergeneric hybridization between Pleurotus sajor-caju and Calocybe indica

Our present study aims to evaluate the biological activities of the six hybrid mushrooms (APS) obtained through the protoplast fusion technique between two mushrooms Calocybe indica and Pleurotus sajor-caju, in our previous study. Antioxidant activity of hybridized mushroom samples was determined by the free radical scavenging method, using DPPH radical, Superoxide radical, and Hydroxyl radical. Additionally, all the mushroom extract has shown a good amount of total phenolic content, and total flavonoid content and also has potent Ferric reducing antioxidant power. The Total phenolic content, Total flavonoid content, and Ferric reducing antioxidant power were estimated. Six constituents: gallic acid, catechin, protocatechuic acid, p-hydroxybenzoic acid, p-coumaric acid, and cinnamic acid were identified by UHPLC. The MIC values, zone of inhibition, growth kinetic, and scanning electron microscopy (SEM) were performed to establish the antimicrobial efficacy. The tested samples exhibited antimicrobial activity against selected microorganisms Staphylococcus aureus, Klebsiella pneumoniae, Bacillus subtilis, Pseudomonas aeruginosa. A clear morphological change was observed under SEM when Bacillus subtilis and Pseudomonas aeruginosa were treated with APS-4 and APS-3 mushroom extracts. The ability to inhibit carbohydrate hydrolyzing enzymes such as α-amylase and α-galactosidase has also been studied to explore antidiabetic properties. The inhibitory activity of α-glucosidase was APS-4 reflected a very prominent result with the lowest IC50 value i.e.,118.058 ± 1.515, APS-2 and APS-6 showed almost similar IC50 values. α – galactosidase inhibitory activity of APS-4 and APS-6 exhibit better results than other strains.

Intergeneric chromosome-specific painting reveals differential chromosomal transmission from Tripidium arundinaceum in sugarcane progeny

Sugarcane has recently attracted increasing attention for its potential as a source of sugar and bioethanol, so increasing its yield is essential to ensure the sugar security and bioenergy production. Intergeneric hybridization is a highly efficient method to produce new genetic variants of crop plants, particularly those species with high ploidy such as sugarcane (Saccharum spp.). Tripidium arundinaceum exhibits many desirable agronomic traits, and has been widely studied to produce hybrids with improved stress tolerance and other characteristics in sugarcane breeding. However, the genetic relationship between T. arundinaceum and Saccharum species, and the individual T. arundinaceum chromosomal compositions in sugarcane hybrids are still elusive. Here we used whole-genome single-nucleotide polymorphisms (SNPs) to ascertain the phylogenetic relationships between these species and found that T. arundinaceum is more closely related to Saccharum than Sorghum, in contrast to the previous narrow genetic analyses using chloroplast DNA. Additionally, oligonucleotide (oligo)-based chromosome-specific painting derived from Saccharum officinarum was able to distinctly identify the chromosomes of T. arundinaceum. We developed the oligo-genomic in situ hybridization (GISH) system for the first time, to unveil the novel chromosome translocations and the transmission of individual T. arundinaceum chromosomes in sugarcane progeny. Notably, we discovered that the chromosomal transmission of T. arundinaceum exhibited several different inheritance modes, including n, 2n, and over 2n in the BC1 progenies. Such inheritance patterns may have resulted from first division restitution (FDR) or FDR+nondisjunction of a chromosome with the sister chromatids in the second meiosis division/second division restitution (FDR+NSC/SDR) model during meiosis. These results will be of substantial benefit for the further selection of T. arundinaceum chromosomes for sugarcane genetic improvement.

The role of deep hybridization in fern speciation: Examples from the Thelypteridaceae.

Hybridization is recognized as an important mechanism in fern speciation, with many allopolyploids known among congeners, as well as evidence of ancient genome duplications. Several contemporary instances of deep (intergeneric) hybridization have been noted, invariably resulting in sterile progeny. We chose the christelloid lineage of the family Thelypteridaceae, recognized for its high frequency of both intra- and intergeneric hybrids, to investigate recent hybrid speciation between deeply diverged lineages. We also seek to understand the ecological and evolutionary outcomes of resulting lineages across the landscape. By phasing captured reads within a phylogenomic data set of GoFlag 408 nuclear loci using HybPhaser, we investigated candidate hybrids to identify parental lineages. We estimated divergence ages by inferring a dated phylogeny using fossil calibrations with treePL. We investigated ecological niche conservatism between one confirmed intergeneric allotetraploid and its diploid progenitors using the centroid, overlap, unfilling, and expansion (COUE) framework. We provide evidence for at least six instances of intergeneric hybrid speciation within the christelloid clade and estimate up to 45 million years of divergence between progenitors. The niche quantification analysis showed moderate niche overlap between an allopolyploid species and its progenitors, with significant divergence from the niche of one progenitor and conservatism to the other. The examples provided here highlight the overlooked role that allopolyploidization following intergeneric hybridization may play in fern diversification and range and niche expansions. Applying this approach to other fern taxa may reveal a similar pattern of deep hybridization resulting in highly successful novel lineages.

Variation and Interaction of Distinct Subgenomes Contribute to Growth Diversity in Intergeneric Hybrid Fish.

Intergeneric hybridization greatly reshapes regulatory interactions among allelic and non-allelic genes. However, their effects on growth diversity remain poorly understood in animals. In this study, we conducted whole-genome sequencing and RNA sequencing (RNA-seq) analyses in diverse hybrid varieties resulting from the intergeneric hybridization of goldfish (Carassius auratus red var.) and common carp (Cyprinus carpio). These hybrid individuals were characterized by distinct mitochondrial genomes and copy number variations. Through a weighted gene correlation network analysis, we identified 3693 genes as candidate growth-regulated genes. Among them, the expression of 3672 genes in subgenome R (originating from goldfish) displayed negative correlations with growth rate, whereas 20 genes in subgenome C (originating from common carp) exhibited positive correlations. Notably, we observed intriguing patterns in the expression of slc2a12 in subgenome C, showing opposite correlations with body weight that changed with water temperatures, suggesting differential interactions between feeding activity and weight gain in response to seasonal changes for hybrid animals. In 40.31% of alleles, we observed dominant trans-regulatory effects in the regulatory interaction between distinct alleles from subgenomes R and C. Integrating analyses of allelic-specific expression and DNA methylation data revealed that the influence of DNA methylation on both subgenomes shapes the relative contribution of allelic expression to the growth rate. These findings provide novel insights into the interaction of distinct subgenomes that underlie heterosis in growth traits and contribute to a better understanding of multiple allele traits in animals.

Contemporary intergeneric hybridization and backcrossing among birds-of-paradise.

Despite large differences in morphology, behavior and lek-mating strategies the birds-of-paradise are known to hybridize occasionally, even across different genera. Many of these bird-of-paradise hybrids were originally described as distinct species based on large morphological differences when compared to recognized species. Nowadays, these specimens are generally recognized as hybrids based on morphological assessments. Having fascinated naturalists for centuries, hybrid specimens of birds-of-paradise have been collected and the specimens kept in Natural History Collections. In the present study, we utilize this remarkable resource in a museomics framework and evaluate the genomic composition of most described intergeneric hybrids and some intrageneric hybrids. We show that the majority of investigated specimens are first-generation hybrids and that the parental species, in most cases, are in line with prior morphological assessments. We also identify two specimens that are the result of introgressive hybridization between different genera. Additionally, two specimens exhibit hybrid morphologies but have no identifiable signals of hybridization, which may indicate that minor levels of introgression can have large morphological effects. Our findings provide direct evidence of contemporary introgressive hybridization taking place between genera of birds-of-paradise in nature, despite markedly different morphologies and lek-mating behaviors.

The Effect of Cryopreserved Sperm on the Early Development, Survival, and Growth of Intergeneric Sterbel Hybrids (Acipenser ruthenus × Huso huso).

The aim of this study was to analyze the survival and growth of intergeneric (Acispenser ruthenus × Huso huso L.) sterbel hybrids obtained by fertilizing sterlet eggs with cryopreserved beluga semen. The rate of embryonic development did not differ between sterbel hybrids (experimental groups) and sterlets (control groups), and the hatching period was identical in all groups. The survival rate of hybrid larvae was higher in the experimental groups than in the control groups. Body weight and body length measurements revealed that sterbel hybrids grew at a faster rate than the control group sterlets. The hybrid origin of sterbels produced with the use of cryopreserved beluga semen was confirmed in a genetic analysis based on species-specific DNA fragments. To the best of the authors' knowledge, this is the first study to analyze the growth of sterbel hybrids derived from cryopreserved semen. The research findings indicate that this type of intergeneric hybridization delivers satisfactory results and can be applied in sturgeon aquaculture.

Contribution to the Embryology, Sporoderm and Spermoderm Pattern of <I>Bothriochloa pertusa</I> (L.) A. Camus, <I>Capillipedium filiculme</I> (Hook.F.) Stapf and <I>Dichanthium annulatum</I> (Forssk.) Stapf with a Brief discussion on its Taxonomic Status

Embryological features in Bothriochloa pertusa, Capillipedium filiculme and Dichanthium annulatum have been studied. The male reproductive characters are constant as evidenced by anther wall development and it corresponds to Monocot type. At maturity the pollen grains are 3-celled. Embryo sac development and embryogeny conforms to Polygonum type and Asterad type respectively. Endosperm, seed coat and pericarp have been studied and data on SEM investigation on pollen wall and seed coat of these taxa are added. The three taxa viz., Bothriochloa, Capillipedium and Dichanthium were considered under Andropogoneae of Panicoideae as separate genera by Bor (1960). De Wet and Harlan (1970) merged them in Dichanthium . The evidences given by them are intergeneric hybridization and production of fertile hybrids between these three genera. Clayton (1977) also followed the concept of merger taking priority. The authors assessed the possibility of merger into Dichanthium on the basis of embryology, sporoderm and spermoderm pattern

Homoplasy rather than intergeneric hybridisation explains mammillose leaf cells in Schistidium mammillosum sp. nov. (Grimmiaceae)

We present a peculiar new species in the Grimmiaceae, Schistidium mammillosum, which is distinct in having mammillose leaf cells and pluristratose lamina. These features are rare in mosses but shared by a few Grimmia species including sympatric G. alpestris. Sporophyte characteristics of the new taxon, in contrast, indicated a species of Schistidium and suggested a possible intergeneric hybrid origin. Nuclear ITS and plastid rps4‒trnF sequence data consistently resolved the new taxon within species of Schistidium, thus contradicting the hybridogenic hypothesis. We suggest that the shared feature of mammillose cells evolved independently in the two genera in adaptation to similar environmental conditions, possibly prolonged snow cover. Supported by morphological similarity, our phylogenetic analyses indicate a sister relationship of S. mammillosum and S. marginale in the Confertum clade. Schistidium mammillosum colonises siliceous rocks in the alpine and nival zone and is to date known from the French Alps and a single locality in Switzerland.

Widening Genetic Diversity Using Embryo Rescue in Cucurbit Crops: A Review.

Embryo rescue is a vital technique in cucurbit breeding and propagation, addressing challenges such as embryo abortion, poor seed viability, and incompatibility barriers. This method involves the excision of immature embryos from seeds followed by their in vitro culture on a nutrient medium, providing an environment conducive to their growth and development. In cucurbits, embryo rescue has been extensively utilized to overcome barriers to hybridization, enabling the production of interspecific and intergeneric hybrids with desired traits. Various factors, including genotype, developmental stage of embryos, and culture conditions, influence the success of embryo rescue in cucurbits. Optimal nutrient formulations, growth regulators, and culture techniques are critical for promoting embryo germination, shoot elongation, and subsequent plantlet establishment. Additionally, embryo rescue facilitates the recovery of valuable genetic material from wild and exotic cucurbit species, expanding genetic diversity and developing novel cultivars with improved traits such as disease resistance, yield, and quality. This review highlights the principles, applications, and advancements in embryo rescue technology in cucurbits, emphasizing its significance in cucurbit breeding programs and crop improvement efforts.

Assessment and Partial Characterization of Candidate Genes in Dihydrochalcone and Arbutin Biosynthesis in an Apple-Pear Hybrid by De Novo Transcriptome Assembly.

Apples (Malus × domestica Borkh.) and pears (Pyrus communis L.) are valuable crops closely related within the Rosaceae family with reported nutraceutical properties derived from secondary metabolites including phloridzin and arbutin, which are distinctive phenolic metabolites characterizing apples and pears, respectively. Here, we generated a de novo transcriptome assembly of an intergeneric hybrid between apple and pear, accumulating intermediate levels of phloridzin and arbutin. Combining RNA-seq, in silico functional annotation prediction, targeted gene expression analysis, and expression-metabolite correlations, we identified candidate genes for functional characterization, resulting in the identification of active arbutin synthases in the hybrid and parental genotypes. Despite exhibiting an active arbutin synthase in vitro, the natural lack of arbutin in apples is reasoned by the absence of the substrate and broad substrate specificity. Altogether, our study serves as the basis for future assessment of potential physiological roles of identified genes by genome editing of hybrids and pears.

Intergeneric hybrid origin of the invasive tetraploid Cirsium vulgare.

The invasive tetraploid Cirsium vulgare hybridizes with both Cirsium and Lophiolepis. Its conflicted position in molecular phylogenies, and its peculiar combination of morphological, anatomical, and genomic features that are alternatively shared with representatives of Cirsium or Lophiolepis, strongly suggest its intergeneric hybrid origin. Genetic relationships of C. vulgare (8 samples) with genus Lophiolepis (11 species) and other representatives of genus Cirsium (12 species) were evaluated using restriction site-associated DNA sequencing (RADseq) and examined using analytical and imaging approaches, such as NeighborNet, Heatmap, and STRUCTURE, to identify nuclear genomes admixture. Estimation of the intensity of spontaneous hybridization within and between Cirsium and Lophiolepis was based on herbarium revisions and published data for all reported hybrids pertinent to taxa currently included in Cirsium or Lophiolepis. The genome of any examined Cirsium species is more similar to C. vulgare than to any Lophiolepis species, and vice versa. The nuclear genome of the tetraploid C. vulgare is composed of two equivalent parts, each attributable either to Lophiolepis or to Cirsium; the organellar RADseq data clustered C. vulgare with the genus Cirsium. Spontaneous hybridization between Cirsium and Lophiolepis is significantly less intensive than within these genera. Our analyses provide compelling evidence that the invasive species C. vulgare has an allotetraploid intergeneric origin, with the maternal parent from Cirsium and the paternal from Lophiolepis. For the purpose of delimiting monophyletic genera, we propose keeping Lophiolepis separate from Cirsium and segregating C. vulgare into the hybridogenous genus Ascalea.

Complete Plastomes of Ten Rorippa Species (Brassicaceae): Comparative Analysis and Phylogenetic Relationships

The genus Rorippa belongs to the family Brassicaceae, and its members usually have high medicinal value. The genus consists of approximately 75 species and mainly grows in the Northern Hemisphere, occurring in every continent except Antarctica. The taxonomy and phylogenetic relationships of Rorippa are still unsettled, largely due to complex morphological variations in Rorippa, which were caused by frequent hybridization events. Here, we sequenced four complete plastid genomes of Rorippa species by Illumina paired-end sequencing. The four new plastid genomes of Rorippa ranged in total size from 154,671 bp for R. palustris to 154,894 bp for R. sylvestris. There are 130 genes in the four plastomes, embodying 8 rRNA, 37 tRNA, and 85 protein-coding genes. Combining with six published plastid genomes, we carried on comparative and phylogenetic analyses. We found that the ten Rorippa plastid genomes were conservative in gene number and order, total size, genomic structure, codon usage, long repeat sequence, and SSR. Fourteen mutational hotspot regions could be selected as candidate DNA barcoding to distinguish Rorippa plants. The phylogenetic trees clearly identified that ten Rorippa species displayed monophyletic relationships within the tribe Cardamineae based on plastomes and nrDNA ITS sequences. However, there are significant cytonuclear discordances in the interspecific relationships within Rorippa, as well as the intergeneric relationships between Rorippa and its related genera. We inferred that the cytonuclear discordance is most likely a result of interspecific hybridization within Rorippa, as well as intergeneric hybridization with its related genera. These plastid genomes can offer precious information for studies of species authentication, evolutionary history, and the phylogeny of Rorippa.

Molecular variation and phylogeography within European Isothecium alopecuroides and Pseudisothecium myosuroides (Bryophyta, Lembophyllaceae)

Abstract Earlier studies on Isothecium s.l. suggested potential interchange of genetic material between species that are nowadays known to belong to separate genera. In this study, we analyse the variation in three molecular markers (nuclear gpd; mitochondrial nad5; and plastid trnG) in a wide selection of Isothecium alopecuroides and Pseudisothecium myosuroides specimens to infer whether this potential exchange of genetic material is frequent. In addition, we explore the phylogeographic structure of these two species in Europe. Our results seem to show repeated genetic interchange for the nuclear and mitochondrial markers in both species, suggesting intergeneric hybridization, although horizontal gene transfer and/or incomplete lineage sorting could also explain the detected incongruences. The genetic lineages found indicate a complex biogeographical history for I. alopecuroides, including both post-glacial immigration from different glacial refugia and developing haplotypes potentially adapted to cold climates. As for P. myosuroides, genetic variants could either indicate a post-glacial immigration history or adaptation to oceanic conditions. Further studies including a larger set of more variable molecular markers could help to reach final conclusions on the results here presented.

Enigmatic host-mite relationships: Unraveling the distribution of quill mites on Birds-of-Paradise

Mites of the family Syringophilidae (Acariformes: Prostigmata: Cheyletoidea) are permanent and obligatory parasites of birds. This study presents an analysis of mite material collected from 22 avian species belonging to the family Paradisaeidae (Passeriformes), revealing the presence of four mite species belonging to four genera: Syringophiloidus attenboroughi n. sp., Peristerophila regiusi n. comb., Picobia frankei, and Gunabopicobia garylarsoni. In the present work, the genus Neoperisterophila is synonymized with the genus Peristerophila. While the genera Syringophiloidus and Picobia were expectedly found on paradisaeid birds, given their prevalence in passerines, the presence of Peristerophila and Gunabopicobia was intriguing, suggesting potential host-switching events. The specificity of these mites varies, with some showing occurrence on hosts of closely related genera and others infesting phylogenetically distant hosts. Notably, the distribution of specific mite species on the Birds-of-Paradise appears to be influenced by both long coevolutionary histories and incidental contacts between often unrelated or intergeneric hybrid species of paradisaeid birds. Furthermore, our research of 104 specimens from 22 Birds-of-Paradise species shows generally low infestation rates across the studied species, suggesting a nuanced interaction between these mites and their avian hosts. Additionally, our network analysis provides a deeper understanding of these host-parasite interactions, revealing a high level of specialization and complexity in these ecological relationships.

Biomass and energy potential of Erianthus arundinaceus and Saccharum spontaneum-derived novel sugarcane hybrids in rainfed environments

BackgroundEnergy canes are viable feedstocks for biomass industries due to their high biomass production potential, lower susceptibility to insects and diseases, better ability to adapt to extreme conditions and clean bioenergy. Interspecific hybrids (ISH) and intergeneric hybrids (IGH) have great potential to meet the growing demand of biomass, biomass-derived energy and feedstock.ResultsIn this study, two types of energy canes, Type I and Type II, derived from S. spontaneum and E. arundinaceous background were evaluated for high biomass, fiber and bioenergy potential under subtropical climate along with the check varieties Co 0238 and CoS 767. Out of 18 energy canes studied, six energy canes, viz., SBIEC11008 (204.15 t/ha), SBIEC11005 (192.93 t/ha), SBIEC13008 (201.26 t/ha), SBIEC13009 (196.58 t/ha), SBIEC13002 (170.15 t/ha), and SBIEC13007 (173.76 t/ha), consistently outperformed the check varieties under Type-I, whereas in type-II, SBIEC11004 (225.78 t/ha), SBIEC11006 (184.89 t/ha), and SBIEC14006 (184.73 t/ha) energy canes produced significantly higher biomass than commercial checks, indicating their superior potential for cogeneration. Estimated energy output from the energy canes (700–1300 GJ/ha/year) exceeded the range of co-varieties (400–500 GJ/ha/year) and energy utilization efficiency in plants and ratoon crops for energy canes viz., SBIEC11008 (3%, 1.97%), SBIEC14006 (1.93%, 2.4%), SBIEC11005 (1.7%, 1.9%), and SBIEC11001 (1.01%, 1.03%), was higher than best checks Co 0238 (0.77, 0.9%). Additionally, energy canes SBIEC 13001 (22.35%), SBIEC 11008 (22.50%), SBIEC 14006 (28.54%), SBIEC 11004 (30.17%) and SBIEC 11001 (27.03%) had higher fiber contents than the co-varieties (12.45%).ConclusionThe study gives insight about the potential energy canes for higher biomass and energy value. These energy cane presents a vital option to meet the future demand of bioenergy, fiber and fodder for biomass due to their versatile capacity to grow easily under marginal lands without competing with cultivated land worldwide.

Rapid and cost-effective molecular karyotyping in wheat, barley, and their cross-progeny by chromosome-specific multiplex PCR

BackgroundInterspecific hybridisation is a powerful tool for increasing genetic diversity in plant breeding programmes. Hexaploid wheat (Triticum aestivum, 2n = 42) × barley (Hordeum vulgare, 2n = 14) intergeneric hybrids can contribute to the transfer of agronomically useful traits by creating chromosome addition or translocation lines as well as full hybrids. Information on the karyotype of hybrid progenies possessing various combinations of wheat and barley chromosomes is thus essential for the subsequent breeding steps. Since the standard technique of chromosome in situ hybridisation is labour-intensive and requires specific skills. a routine, cost-efficient, and technically less demanding approach is beneficial both for research and breeding.ResultsWe developed a Multiplex Polymerase Chain Reaction (MPCR) method to identify individual wheat and barley chromosomes. Chromosome-specific primer pairs were designed based on the whole genome sequences of ‘Chinese Spring’ wheat and ‘Golden Promise’ barley as reference cultivars. A pool of potential primers was generated by applying a 20-nucleotide sliding window with consecutive one-nucleotide shifts on the reference genomes. After filtering for optimal primer properties and defined amplicon sizes to produce an ordered ladder-like pattern, the primer pool was manually curated and sorted into four MPCR primer sets for the wheat A, B, and D sub-genomes, and for the barley genome. The designed MPCR primer sets showed high chromosome specificity in silico for the genome sequences of all 18 wheat and barley cultivars tested. The MPCR primers proved experimentally also chromosome-specific for the reference cultivars as well as for 13 additional wheat and four barley genotypes. Analyses of 16 wheat × barley F1 hybrid plants demonstrated that the MPCR primer sets enable the fast and one-step detection of all wheat and barley chromosomes. Finally, the established genotyping system was fully corroborated with the standard genomic in situ hybridisation (GISH) technique.ConclusionsWheat and barley chromosome-specific MPCR offers a fast, labour-friendly, and versatile alternative to molecular cytogenetic detection of individual chromosomes. This method is also suitable for the high-throughput analysis of distinct (sub)genomes, and, in contrast to GISH, can be performed with any tissue type. The designed primer sets proved to be highly chromosome-specific over a wide range of wheat and barley genotypes as well as in wheat × barley hybrids. The described primer design strategy can be extended to many species with precise genome sequence information.