Use Of Interspecific Hybridization Research Articles

Increasing resistance to coccomycosis in sweet cherry by applying distant hybridization with cherry species

To reduce the pesticide load in industrial plantings, it is necessary to use pathogen-resistant varieties when establishing orchards. The problem of obtaining stable, large-fruited, adaptive varieties is acute, since there are practically no genotypes in the existing assortment that combine a complex of economically valuable traits with resistance to diseases. The isolation of new resistance genes in wild forms and the creation of genotypes resistant to fungal diseases on their basis is possible through the use of remote hybridization. Interspecific hybrids with sweet cherry were obtained at the Krymsk EBS, VIR Branch, which combine resistance to coccomycosis and increased fruit size. These genotypes are complex sources of traits for further breeding work in obtaining adaptive, large-fruited genotypes. The work carried out proves that the use of interspecific hybridization makes it possible to obtain genomes highly resistant to coccomycosis.

Saccharomyces arboricola and Its Hybrids’ Propensity for Sake Production: Interspecific Hybrids Reveal Increased Fermentation Abilities and a Mosaic Metabolic Profile

The use of interspecific hybrids during the industrial fermentation process has been well established, positioning the frontier of advancement in brewing to capitalize on the potential of Saccharomyces hybridization. Interspecific yeast hybrids used in modern monoculture inoculations benefit from a wide range of volatile metabolites that broaden the organoleptic complexity. This is the first report of sake brewing by Saccharomyces arboricola and its hybrids. S. arboricola x S. cerevisiae direct-mating generated cryotolerant interspecific hybrids which increased yields of ethanol and ethyl hexanoate compared to parental strains, important flavor attributes of fine Japanese ginjo sake rice wine. Hierarchical clustering heatmapping with principal component analysis for metabolic profiling was used in finding low levels of endogenous amino/organic acids clustered S. arboricola apart from the S. cerevisiae industrial strains. In sake fermentations, hybrid strains showed a mosaic profile of parental strains, while metabolic analysis suggested S. arboricola had a lower amino acid net uptake than S. cerevisiae. Additionally, this research found an increase in ethanolic fermentation from pyruvate and increased sulfur metabolism. Together, these results suggest S. arboricola is poised for in-depth metabolomic exploration in sake fermentation.

Status and recommendations for sustainable freshwater aquaculture in Brazil

AbstractBrazil is a megadiverse country and is participant of fundamental environmental agreements for biodiversity conservation. However, the internal politics and the cultures that affect negatively the ecological integrity in Brazilian freshwater need to be improved on the condition of sustainable management. Scientific community, the government and stakeholders are in constant conflicts of goals. Meanwhile, the current model for Brazilian aquaculture shows problems of ecological impact due to the lack of appropriated planning and legislation to the aquatic biota. The non‐recognition of sustainable census incorporated in its environmental politics reflects in an archaic and unsustainable management, with the following characters: a non‐specific approach for technical management, the indiscriminate use of interspecific hybrids and non‐native species and the lack of skilled labour. The potential impact on native species and the introduction of pathogens are the main negative effects on aquatic biota. This way, the aim of this article is to elucidate the conflicts of interests and ecological effects of fish aquaculture in Brazil, besides providing good practices and sustainable alternatives for management.

Interspecific Hybridization for Brassica Crop Improvement

Interspecific hybridization is widespread in nature, where it can lead to either the production of new species or to the introgression of useful adaptive traits between species. In agricultural systems, there is also great potential to take advantage of this process for targeted crop improvement. In the Brassica genus, several crop species share close relationships: rapeseed (Brassica napus) is an ancestral hybrid between turnip (B. rapa) and cabbage (B. oleracea), and mustard species B. juncea, B. carinata and <i>B. nigra</i> share genomes in common. This close relationship, plus the abundance of wild relatives and minor crop species in the wider Brassiceae tribe which readily hybridize with the Brassica crop species, makes this genus an interesting example of the use of interspecific hybridization for crop improvement. In this review we introduce the Brassica crop species and their wild relatives, barriers to interspecific and intergeneric hybridization and methods to overcome them, summarize previous successful and unsuccessful attempts at the use of interspecific hybridization for crop improvement in Brassica, and provide information about resources available to breeders wishing to take advantage of this method in the Brassica genus.

THE INTERSPECIFIC HYBRIDS OF ONION WITH HIGH DEGREE OF RESISTANCE TO A PERONOSPOROZ AND HIGH CONTENT OF NONVOLATILE SOLID

The problem of stability of plants of the onion to the most nocuous diseases acquired in the world a paramount value. Untrue mealy dew or peronosporoz onion related to their number, astonishes many kinds of the sort Allium L. and, primarily, onion napiform. Information of presence of immune grades of the onion of napiform are absent, are just of the grade with various level of stability. In years, the favorable for development of this disease, it can cause larger losses at cultivation a sevka, onions turnip and seeds. This disease almost everywhere is widespread. The activator of a peronosporoz is the mushroom of Peronospora destructor (Berk) of Casp. the typical obligate parasite living and eating on the growing plants and striking leaves and flower-colored. Use of expensive chemical means of struggle just limits dissemination of peronosporoz, but radically does not solve the problem of protection of plants, not to mention deterioration in an ecological situation. At selection of the onion of napiform to resistance to peronosporoz interspecific hybridization is the most promising, though this way is long and difficult. The main purpose with the use of interspecific hybridization is creation of forms combining presence of stored bulbs and with high resistance to peronosporoz and sufficient a fecundity. The pollen of plants for transfer of genes supervising high stability and high content they be valuable substances from multi-annual onions to the onion to napiform. In the article results of joint researches of the laboratory of selection of onions cultures, genetics and cytology, immunity of the All-Russian Scientific Research Institute of selection and seed farming of vegetable cultures (VNIISSOK) on development of methods of interspecific hybridization and creation of the forms of interspecific hybrids combining presence of stored bulb with high resistance to peronosporoz, the technology of selection process, results of selection and interspecific hybrids of the onion created in the VNIISSOK and approved to use in various Russia regions are presented.

USE OF INTERSPECIFIC HYBRIDIZATION IN THE BREEDING OF ADAPTIVE HYBRIDS AND SORTS OF GARDEN CHRYSANTHEMUM (Chrysanthemum morifolium Ramat.)

Many garden chrysanthemums bred across the world are not fully winter hardy. Many are damaged by fungal diseases due to a high humidity and are late flowering. This makes them unsuitable for general commercial marketing. Since 2000 we have been conducting a breeding program using natural species of the genus Chrysanthemum that are adapted to the local conditions. The strategy of breeding adaptive hybrids and varieties of chrysanthemum native to Russia was proposed based on their biological, genetic peculiarities and natural resources of Chrysanthemum with the use of interspecific hybridization. Research objects are the first generations of interspecific hyb rids of F1obtained previously by the author as a result of the hybridization of varieties and wild species of Chrysanthemum. Derived from different species and varieties, F1hybrids were crossed among themselves to obtain the multicomponent F2progeny. F2seedlings with winter hardiness, resistance to Puccinia horiana Henn. and early flowering were used in closely related crosses. The offspring of F3from closely related crosses were also assessed and selected according to adaptive and decorative characteristics. Inclusion in the selection process of various sources of winter hardiness and resistance to P. horiana allowed positive characteristics to be increased in F2and to be revealed in F3. Adaptive signs of the wild species Chrysanthemum naktongense Nakai, C. coreanum (H. Lév. et Vaniot) Nakai, C. zawadzkii var. tenuisectum Kitag., C. leiophyllum Nakai, and C. zawadzkii subsp. acutilobum (DC.) Kitag., which have formed and fixed during evolution, were inherited and manifested in offspring of the multicomponent hybrids and the closely related crosses. Promising interspecific forms with biological signs determining the possibility of growing in extreme conditions of the subregion were selected.

DEVELOPMENT OF NEW FORMS OF TREE-SHAPED TOMATO AND THEIR USE IN BREEDING PROGRAM

Tree-shaped plants of tomato have many useful traits, which gain them advantages over common tomato forms. In world plant collection there are over 200 accessions, cultivars and hybrids of tree-shaped tomato. The aim of the study was to develop new initial tomato accessions for breeding program for tree-shaped cultivars and hybrids that are distinguished by a shape, fruit weight and color, improved by interspecific hybridization chemical composition and resistance to the major diseases. The tree-shaped breeding lines: ‘196/12’, ‘374/08’, ‘909/14’, ‘911/14’ and other were observed with the use of interspecific hybridization and selection in the population F2-F4. The selected lines passed the trial in artificially infected condition with Alternaria, viral diseases (MToV, TSWV) and phytoplasmas. Among breeding lines assessed the ‘911/14’, ‘374/08’ and‘40/11’ were less affected by complex of pathogens. The lines ‘196/12’ and ‘909/14’ passed an assessment in the nursery for variety trial in naturally and provocatively infected conditions with major pathogens. Both breeding lines had an advantage over standard accession ‘Laguna’ and ‘Maraphon’ for total yield capacity and standard fruit harvest; it was more by 9.6% and 52.2% and 9.5% and 53.4% respectively. Fruits of lines 196/12 and 909/14 had good taste quality with high content of dry matter (5.8% and 6.8%), sugars (3.3% and 3.1%), vitamin C (22.2 and 24.8 mg/100 grams). The selected tree-shaped accessions have been used to develop heterotic hybrids and to be sources of economically valuable traits.

EVALUATION OF PRUNUS KANSUENSIS AS A GENETIC TESTER FOR PEACH

Mapping of traits in peach is hindered by the low heterozygocity encountered in peach × peach crosses. Typical heterozygocity rates in peach × peach crosses are in the range of 25-35% percent. The use of interspecific hybrids greatly increases the number of heterozygous markers in F1 hybrids and facilitates the making of genomic maps without blind regions. We have initiated the evaluation of Prunus kansuensis Rehder as a parent for genetic studies in peach. Peach × P. kansuensis F1 and F2 populations have been generated. F1 hybrids are vigorous, healthy and highly fertile producing large numbers of F2 seed. F2 seedlings are precocious with over 75% of seedlings producing flower buds by 18 months age. F2 seedlings show little evidence of inbreeding depression or hybrid breakdown.

Reproductive biology of three commercially valuable Santalum species: development of flowers and inflorescences, breeding systems, and interspecific crossability

Santalum (sandalwood) spp. are hemi-parasitic trees, the heartwood of which produces valuable aromatic oil. There appears to be a significant commercial opportunity for establishment of a planted sandalwood resource. However, lack of basic biological knowledge is one constraint on such development. The study reported here addresses one such constraint. Controlled pollination using 13 genotypes of Santalum lanceolatum was undertaken to elucidate (i) self-incompatibility (ii) intraspecific cross-compatibility in the species, and (iii) interspecific cross-compatibility with S. album and S. austrocaledonicum. S. lanceolatum may be considered to have a facultative allogamous (incomplete outbreeding) breeding system. This study found variation between genotypes in the level of putative self-incompatibility: some (20%) were found to set seed following self-pollination, while the remaining 80% had no seed development with such pollinations. However, a significantly greater proportion of genotypes developed seed following intraspecific cross-pollination (62%) compared with self-pollination (20%). While total geographic isolation and significant morphological divergence exists between S. lanceolatum with each of S. album and S. austrocaledonicum this study found no indication of reproductive barrier(s) between them, indicating potential for use of interspecific hybridization in genetic improvement, but also suggesting the potential of undesirable gene flow between native and introduced species.

Giemsa C-banding in Asiatic taxa of Hordeum section Stenostachys with notes on chromosome morphology

C-banding patterns of eight cytotypes of six Asiatic taxa of Hordeum sect. Stenostachys were characterized by (1) the small size of most centromeric bands, (2) the paucity and generally small size of the intercalary bands and of the bands at the secondary constrictions, and (3) the existence in some taxa of conspicuous and, particularly in H. brevisubulatum ssp. violaceum, 2x, even large telomeric bands. The large variation in C-banding patterns surpasses that earlier observed in the genus and agrees with that of other genera. C-band polymorphism was widespread except within plants of self-compatible taxa. The C-banded area of the chromosomes was estimated to vary between 3 and 18 % in different taxa. Basic C-banded karyotypes of four taxa were produced through the use of interspecific hybrids. Certain identification of taxa, based on C-banding patterns alone, proved questionable. Obvious chromosome polymorphisms were observed in SAT-chromosomes of one taxon.

Impact of Wide Hybridization on Highbush Blueberry Breeding

The use of interspecific hybridization in blueberry (Vaccinium L. section Cyanococcus Gray) breeding has resulted in the incorporation of novel traits from wild germplasm and the expansion of the geographic limits of highbush blueberry (V. ×corymbosum L.) production. The objectives of this study were: 1) to estimate the impact of wide hybridization on inbreeding, heterozygosity, and coancestry of the cultivated tetraploid highbush blueberry; 2) to establish the usefulness of microsatellite markers in assessing genetic relationships among southern highbush blueberry [SHB (V. ×corymbosum)] cultivars; and 3) to report on the expected genetic contribution of wild Vaccinium clones to SHB cultivars. Pedigrees of 107 highbush blueberry cultivars were used to calculate tetrasomic inbreeding coefficients (F), pedigree-based genetic distances, and expected genetic contributions of wild clones. Genotyping data from 21 single-locus microsatellite markers screened across 68 genotypes were used to calculate heterozygosity and proportion of shared alleles distances (Dsa). The results indicated that the effects of wide hybridization on genetic diversity of cultivated blueberry were lower than previously thought. First, SHB cultivars exhibited similar levels of molecular relatedness as historical northern highbush blueberry [NHB (V. ×corymbosum)] cultivars (median Dsa between pairs of cultivars equals 0.19 in both cultivar groups), despite the broader genetic base and larger pedigree distances in the former cultivar group. Second, levels of heterozygosity in modern NHB cultivars were not statistically different from those of SHB (χ2 = 4.0; df = 3; P &gt; 0.05), despite the considerably higher levels of inbreeding in the former cultivar group (median F equal to 0.0035 and 0.0013, respectively). Furthermore, pedigree-based genetic distances were significantly correlated with Dsa (r = 0.57, P ≤ 0.0001), indicating that microsatellite markers are reliable tools in most cases to assess the genetic relationships among SHB cultivars. Finally, seven Vaccinium species constitute the current genetic base of cultivated SHB. In this article, we report on the expected genetic contributions of V. angustifolium Ait., V. constablaei Gray, V. corymbosum, V. darrowii Camp, V. elliottii Chapman, V. tenellum Ait., and V. virgatum Ait. (syn. V. ashei Reade) clones to 38 SHB cultivars.

Unreduced gametes are the major causal factor for the production of polyploid interspecific hybrids in Primula

The genus Primula (Primulaceae) consists of approximately 420 species that mainly inhabit temperate to cold regions of the Northern hemisphere. Although most species have attractive flowers with high ornamental value, few have been cultivated as ornamental plants. To develop novel ornamental crops and to introduce novel useful characters, these unexploited rich germplasms of the genus Primula have the potential to serve as breeding materials through the use of interspecific hybridization. However, interspecific hybrids of this genus have rarely been produced, and embryo rescue is one of the most useful strategies to overcome the difficulty of achieving successful hybridization, especially in wide crosses. In recent studies, we successfully obtained various interspecific hybrids in wide cross combinations in Primula using the embryo rescue technique, and showed that unexpected polyploid hybrids were frequently produced by the fertilization of unreduced female and/or male gametes, which were formed in most of the species examined. Some of the resultant hybrids have useful and attractive characters, and they have already been used directly as novel cultivars or incorporated into commercial breeding of novel types of primulas.

Use of interspecific hybridization for increasing buckwheat tolerance to inbreeding

The productivity of inbred buckwheat lines I1–I8 with the homostyly gene of Fagopyrum esculentum and Fagopyrum homotropicum is studied. The species F. homotropicum is recommended for use in buckwheat breeding as a donor of homostyly and tolerance to inbreeding depression.

Dollar Spot Resistant Hybrids between Creeping Bentgrass and Colonial Bentgrass

Creeping bentgrass (Agrostis stolonifera L.) is an important turfgrass species used extensively on golf courses. It is highly susceptible to the fungal pathogen Sclerotinia homoeocarpa F.T. Bennett, the causal agent of dollar spot disease. There is a wide range in degree of susceptibility among current cultivars, with a limited number that have improved resistance. Colonial bentgrass (A. capillaris L.), a related species, has good resistance to dollar spot. We have produced interspecific hybrids between creeping bentgrass and colonial bentgrass and field‐tested them against dollar spot. Some of the hybrids had excellent dollar spot resistance, exhibiting essentially no disease symptoms. This is the first formal report of evaluation of interspecific hybrids between creeping bentgrass and colonial bentgrass for an agronomically important trait. The results presented here suggest that the use of interspecific hybrids may be a useful new approach in Agrostis breeding programs.

Roles of interspecific hybridization and cytogenetic studies in sunflower breeding

The abundance and diversity of species within the genus Helianthus offer numerous and rewarding possibilities to sunflower breeders. All annual species and a large number of perennial species may be crossed to the cultivated sunflower by the conventional hybridization method. On the other side, the divergence and heterogeneity of the genus cause considerable difficulties, such as cross-incompatibility, embryo abortiveness, sterility and reduced fertility in interspecific hybrids. Because of that, methods of somatic hybridization, "in vitro" embryo culture, chromosome doubling, etc. are frequently used for interspecific crossing. Cytogenetic studies are used for determinations of chromosome number and structure and analyses of meiosis (microsporogenesis) and pollen viability, making it possible to establish phylogenetic relations between wild sunflower species and the cultivated sunflower and enabling the use of the former in sunflower breeding. Cytogenetic studies of the sunflower have evolved from cytology through cytotaxonomy and classic Cytogenetic to cytogenetic-molecular studies. Most intensive progress of Cytogenetic studies has been associated with the use of interspecific hybridization in sunflower breeding.

Multiple Disease Resistance in Interspecific Hybrids of Potato.

Wild species of Solanum are excellent sources of disease resistance genes that may be incorporated into S. tuberosum through breeding. This study was initiated to determine whether multiple forms of disease resistance could be identified in interspecific Solanum hybrids. Thirty-two clones were evaluated for resistance to soft rot, common scab, black scurf, Verticillium wilt, and early blight. Most of the clones originated from populations that were not initially selected for disease resistance traits. Comparisons with the cultivars Atlantic, Russet Norkotah, and Russet Burbank indicated that all clones were more resistant than at least one cultivar for at least one disease resistance trait. Clone C545, which exhibited improved resistance to soft rot, scab, pitted scab, early dying disease, and early blight, appears to be an especially valuable source of disease resistance. The use of interspecific hybridization at the diploid level, combined with sexual polyploidization to return to the tetraploid level, provides a method to introduce multiple forms of disease resistance into advanced clones.

The use of inter-specific hybrids in aquaculture and fisheries

Inter-specific hybrid fishes have been produced for aquaculture and stocking programmes to increase growth rate, transfer desirable traits between species, combine desirable traits of two species into a single group of fishes, reduce unwanted reproduction through production of sterile fish or mono-sex offspring, take advantage of sexual dimorphism, increase harvestability, increase environmental tolerances, and to increase overall hardiness in culture conditions. Hybrids constitute a significant proportion of some countries' production for certain taxa; for example, hybrid striped bass in the USA, hybrid clarid catfish in Thailand, hybrid characids in Venezuela, and hybrid tilapia in Israel. Despite its widespread use, there is a general impression that inter-specific hybridization is not a very useful tool for aquaculture. We believe this impression stems from inaccurate reporting of some useful hybrids, limited testing of strains used for hybrids, and from early work on salmonids that did not result in hybrids of commercial advantage.Experimentation with new hybrid fishes is ongoing, especially in marine culture systems where sterile fish may be preferred because of the concern that fish may escape into the marine and coastal environment.Hybridization has been used in tandem with polyploidization to improve developmental stability in hybrid progeny. The results of inter-specific hybridization can be variable and depend on the genetic structure (including the sex) of the parent fish. Inadvertent hybridization and backcrossing can lead to unexpected and undesirable results in hybrid progeny, such as failure to produce sterile fish, loss of color pattern, and reduced viability.Hybridization is only one tool to improve aquaculture production and will require knowledge of the genetic structure of the broodstock, good broodstock management and monitoring of the viability and fertility of the progeny. Hybridization does represent a genetic modification wherein genes are moved between different species; implications for biodiversity conservation and regulation of this type of modification are discussed.

Genetic relationships among domesticated and wild sunflowers (Helianthus annuus, Asteraceae)

Randomly amplified polymorphic DNA (RAPD) loci were used to investigate the origin and genetic relationships of the domesticated sunflower and its wild relatives. A total of 13 primers was employed for the PCR amplifications, from which 68 polymorphic loci were scored. Analysis of RAPD data supports the origin of the domesticated sunflower from wildH. annuus. The high RAPD identity between wild and domesticatedH. annuus (I = 0.976 to I = 0.997) is concordant with a progenitorderivative relationship. However, the identities are very high and therefore provide little information regarding the geographic origin of the domesticated sunflower. Nonetheless, some inferences concerning relationships among domesticated sunflower accessions can be made. The native American varieties and old landracesform a genetically cohesive group based on RAPD evidence, probably due to their origin prior to the use of interspecific hybridization in the development of sunflower cultivars. In contrast, the modern cultivars are not genetically cohesive, perhaps due to the extensive use of intraspecific and interspecific hybridization in the development of modern sunflower varieties. Likewise, little concordance was observed between the geographical origin and genetic clustering of wild populations—an observation probably best explained by the weedy, human dispersed nature of wildH. annuus populations. The information presented here may be a reliable indicator of genetic relationships among wild and domesticated sunflower accessions. However, the processes generating the observed relationships are complex, and the occurrence of unexpected groupings or absence of predicted ones will probably remain difficult to understand.

PROGENY SEX RATIOS IN DIOECIOUS SILENE LATIFOLIA (CARYOPHYLLACEAE).

Most sex ratios reported for Silene latifolia are female biased. As a result of experiments performed by Correns in the early 1900s, pollen tube competition has generally been accepted as the primary cause of these skewed ratios. We did four sets of hand pollinations in which we varied the size of pollen loads and placement of pollen along the filamentous stigma. The effect of pollen load size on progeny sex ratios was not statistically significant. Of 32 maternal families, 17 contained more females than males (one ratio deviated statistically from 1:1), and 13 contained more males than females. Paternal families exhibited a greater range of sex ratios, including three with a significant female bias and one with a significant male bias. Within experiments, neither the maternal parent nor where pollen was placed had a statistically significant effect on progeny sex ratios; the paternal effect was significant in one experiment. We suggest that sex ratios in Silene latifolia are not necessarily affected by the level of pollen competition. Other factors, including variation among males and sex-linked mortality, may help explain the skewed sex ratios that characterize populations of this species. Further, Correns' observations of excess females may have resulted from his use of interspecific hybrids.

Inheritance of morphological and chemical characters in interspecific hybrids between Papaver bracteatum and Papaver pseudo-orientale

The alkaloid profiles and morphological traits of the capsules of Papaver bracteatum, P. pseudo-orientale, and their hybrids were studied. Dominance of the hexaploid parent P. pseudo-orientale was observed for various characters. A genetic model assuming allelic additive effects and polysomic inheritance was elaborated for the control of isothebaine content in the capsules. The distribution of thebaine content in the segregating generations, F2 and BCF1 was evidence of the transfer of genes from the diploid parent P. bracteatum in the gametes of the interspecific hybrid and their expression in its progenies. These findings indicate the potential use of inter-specific hybrids between the Oxytona species in the breeding of cultivars for industrial or ornamental purposes.