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The maize breeding programs focuses on the development of homozygous parental lines for hybrid breeding to obtain heterosis. The Improvement of homozygous lines in a effective time is crucial for hybrid maize breeding. Objectives of this research were to obtain homozygous lines of maize in a short time by using of in-vivo maternal haploid (DH) technique and characterizing them morphologically. The experiments were carried out at the Eastern Mediterranean Agricultural Research Institute(EMARI). Inducers, RWS, RWK-76 and their hybrid RWS X RWK-76 were used as male parent. As female parent, 56 F2 segregated material obtained by selfing of 66 F1 hybrids developed in maize breeding program of Eastern Mediterranean Agricultural Research Institute (EMARI) and 2 F2 segregated material selected from the open pollinated plants of 9 commercial maize variety. As a result of the experiment, 29 doubled haploid lines (DH) were developed. In the developed DH lines, days to tasseling, plant height, height of first ear , ear length, ear diameter, number of kernel per ear and thousand kernel weight varied as 57-78 days, 151-248 cm, 43-112 cm, 11.20-24.50 cm, 24-45 mm, 224-537 kernels/ear, and 180-320 g, respectively. In conclusion, in-vivo maternal DH technique is a highly effective method for obtaining homozygous lines

Double haploids (DHs) production and utilization is an important aspect of wheat breeding programs in worldwide, because, it provides many advantages over the conventional breeding program. Therefore, in vitro and in vivo responses of anther derived two bread wheat cultivars and their F1 crosses were investigated. Results showed significant genetic variation among the tested bread wheat genotypes. The pre-cold treated anther derived embryonic calli and shoot induction (%) were obtained from all genotypes that ranged 44 - 76% and 32 - 58% respectively. The highest shoot induction from embryonic calli was achieved from F1 cross of Zubkov x Atay-85, whereas, lowest induction was obtained from Atay-85 cultivar. The F1 cross (Zubkov x Atay-85) showed a better response in anther culture in term of shoots per plant and root induction than their respective parental genotypes.The present results indicated positive and significant heterotic effects of F1 crosses for calli and shoot induction that also showed less albino plant regeneration after colchicine treatments. Total number of 114 anthers driven DHs lines from two genotypes and their F1 crosses were regenerated, confirmed by flow-cytometry and evaluated under field condition. Some DHs lines were found to be significantly superior for agronomical traits including seed yield than the parental genotypes as well as local bread wheat (control) cultivars.

Zinc (Zn) deficiency is a common limiting factor in agricultural soils, which leads to significant reduction in both the yield and nutritional quality of agricultural produce. Exploring the quantitative trait loci (QTL) for shoot and grain Zn accumulation would help to develop new barley cultivars with greater Zn accumulation efficiency. In this study, two glasshouse experiments were conducted by growing plants under adequate and low Zn supply. From the preliminary screening of ten barley cultivars, Sahara (0.05 mg/pot) and Yerong (0.06 mg/pot) showed the lowest change in shoot Zn accumulation, while Franklin (0.16 mg/pot) had the highest change due to changes in Zn supply for plant growth. Therefore, the double haploid (DH) population derived from Yerong × Franklin was selected to identify QTL for shoot mineral accumulation and biomass production. A major QTL hotspot was detected on chromosome 2H between 31.91 and 73.12 cM encoding genes for regulating shoot mineral accumulations of Zn, Fe, Ca, K and P, and the biomass. Further investigation demonstrated 16 potential candidate genes for mineral accumulation, in addition to a single candidate gene for shoot biomass in the identified QTL region. This study provides a useful resource for enhancing nutritional quality and yield potential in future barley breeding programs.

Abstract Background Farmed Atlantic salmon are one of the most economically significant global aquaculture products. Early sexual maturation of farmed males represents a significant challenge to this industry and has been linked with the vgll3 genotype. However, tools to aid research of this topic, such as all-male and clonal fish, are still lacking. The present 6-year study examined if all-male production is possible in Atlantic salmon, a species with heteromorphic sex chromosomes (males being XY, females XX), and if all-male fish can be applied to further explore the vgll3 contribution on the likelihood of early maturation. Results Estrogen treatment of mixed sex yolk sac larvae gave rise to one sexually mature hermaphrodite with a male genotype (XY) that was used to produce both self-fertilized offspring and androgenetic double haploid (dh) offspring following egg activation with UV treated sperm and pressure shock to block the first mitotic division. There were YY supermales among both offspring types, which were crossed with dh females. Between 1 and 8% of the putative all-male offspring from the eight crosses with self-fertilized supermales were found to have ovaries, and 95% of these phenotypic females were also genetically female. None of the offspring from the one dh supermale cross had ovaries. When assessing the general contribution of the vgll3 locus on the likelihood of early post-smolt sexual maturation (jacking) in the all-male populations we found individuals that were homozygous for the early maturing genotype (97%) were more likely to enter puberty than individuals that were homozygous for the late maturing genotype (26%). However, the likelihood of jacking within individuals with an early/late heterozygous genotype was higher when the early allele came from the dam (94%) compared to the sire (45%). Conclusions The present results show that supermale Atlantic salmon are viable and fertile and can be used as a research tool to study important aspects of sexual maturation, such as to further explore the sex dependent parental genetic contribution to age at puberty in Atlantic salmon. In addition, we report the production of viable double haploid supermale fish.

To facilate breeding process of Brassica napus, a microspore culture and molecular marker-assisted screening combined system were proposed in this research. At early flowering stage, F1 offspring of hybridized combination HY15A ​× ​HF06 was used as donor for microspore culture to analyze effects of colchicine concentration on embryogenic and diploid rates of microspore. Treatment with 50 ​mg/L colchicine resulted in embryogenic rate of 3.56 embryos/bud, which was substantially higher than control (0.78 embryos/bud). A total of 1,387 embryos and 862 single plants were obtained after induction culture. Ploidy detection was performed for the regenerated plants by flow cytometry. Diploid rates of microspores treated with 50 ​mg/L and 70 ​mg/L colchicine were 17.2% and 21.0% respectively, which was significantly higher than control (10.5%). Totally 108 single plants that doubled successfully were randomly selected and screened using molecular marker BE10. Approximately 54 of 108 plants generated a 305 bp amplification product, whereas the other 54 plants showed a 398 bp band, thereby satisfying 1:1 separation ratio (x20.05 ​= ​0.0093). These coincided with field identification results. Findings of this study indicated that homozygous breeding material could be obtained by microspore culture in a short time, thereby remarkably accelerate breeding.

The development of Fusarium head blight (FHB)-resistant winter wheat cultivars using the gene Fhb1 has been conducted in northern China. Sumai 3, a Chinese FHB-resistant spring wheat cultivar, carries three FHB resistance genes: Fhb1, Fhb2 and Fhb5. To better use these genes for increasing FHB resistance in northern China, it is necessary to elucidate the pyramiding effects of Fhb1, Fhb2 and Fhb5 in winter wheat backgrounds. Eight gene combinations involving Fhb1, Fhb2 and Fhb5 were identified in a double haploid (DH) population, and the effects on FHB resistance were evaluated in six tests. At the single gene level, Fhb1 was more efficient than the other two genes in single-floret inoculation tests, whereas Fhb5 showed better resistance than Fhb1 and Fhb2 under a natural infection test. Pyramiding Fhb1, Fhb2 and Fhb5 showed better FHB resistance than the other gene combinations. Forty-nine DH lines showing consistently better resistance than the moderately susceptible control Huaimai 20 in multiple tests were evaluated for main agronomic traits, and no difference in grain yield was found between the mean values of DH lines and the recipient parents Lunxuan 136 and Lunxuan 6, which are higher than those of recipient parent Zhoumai 16 and the donor parent Sumai 3 (p < 0.05). Based on the phenotypic and genomic composition analyses, five promising DH lines fully combined the FHB resistance of donor Sumai 3 and the elite agronomic traits from the recipient parents. This study elucidates the pyramiding effects of three FHB resistance genes and that the promising DH lines with resistance to FHB can be directly applied in wheat production or as parents in winter wheat breeding programs.

For Russia countries with a temperate climate, with direct sowing of rice increase of cold tolerant varieties in seed germination and shoot formation are important. This trait allows to begin rice sowing earlier using for plant growing the favorable period by temperature to obtain optimum shoots by density that gives the chance to realize potential efficiency of varieties. A research objective is to create and estimate the initial stock resistant to low positive temperatures for use it for breeding of new cold tolerant rice varieties.Display of molecular markers - is neutral in relation to a phenotype and they can be found out at any stage of development of plants in ontogenesis. Methods of DNA-genotipirovanija and PCR analysis by means of molecular markers allow accelerating carrying over of the necessary genes in the course of breeding and to provide creation of new varieties with a complex of the set properties Therefore the role of biotechnological methods is important at creation new cold tolerant varieties.According to results of PCR analysis by use of SSR - marker lines of rice with dominant alleles of cold resistance genes were screened. Double haploids were obtained by anther culture method in vitro and resistant forms were found. Plants with economically valuable traits were screened. All-round evaluation of obtained material gave the possibility to find initial stock for use breeding process in future for release of new cold resistant rice varieties.

For Russia countries with a temperate climate, with direct sowing of rice increase of cold tolerant varieties in seed germination and shoot formation are important. This trait allows to begin rice sowing earlier using for plant growing the favorable period by temperature to obtain optimum shoots by density that gives the chance to realize potential efficiency of varieties. A research objective is to create and estimate the initial stock resistant to low positive temperatures for use it for breeding of new cold tolerant rice varieties.Display of molecular markers - is neutral in relation to a phenotype and they can be found out at any stage of development of plants in ontogenesis. Methods of DNA-genotipirovanija and PCR analysis by means of molecular markers allow accelerating carrying over of the necessary genes in the course of breeding and to provide creation of new varieties with a complex of the set properties Therefore the role of biotechnological methods is important at creation new cold tolerant varieties.According to results of PCR analysis by use of SSR - marker lines of rice with dominant alleles of cold resistance genes were screened. Double haploids were obtained by anther culture method in vitro and resistant forms were found. Plants with economically valuable traits were screened. All-round evaluation of obtained material gave the possibility to find initial stock for use breeding process in future for release of new cold resistant rice varieties.

Production of homozygous lines derived from transgenic plants is one of the important steps for phenotyping and genotyping transgenic progeny. The selection of homozygous plants is a tedious process that can be significantly shortened by androgenesis, cultivation of anthers, or isolated microspores. Doubled haploid (DH) production achieves complete homozygosity in one generation. We obtained transgenic homozygous DH lines from six different transgenic events by using anther culture. Anthers were isolated from T0 transgenic primary regenerants and cultivated in vitro. The ploidy level was determined in green regenerants. At least half of the 2n green plants were transgenic, and their progeny were shown to carry the transgene. The process of dihaploidization did not affect the expression of the transgene. Embryo cultures were used to reduce the time to seed of the next generation. The application of these methods enables rapid evaluation of transgenic lines for gene function studies and trait evaluation.

The selection of desirable genotypes with recessive characteristics, such as self-incompatible plants, is often difficult or even impossible and represents a crucial barrier in accelerating the breeding process. Molecular approaches and selection based on molecular markers can allow breeders to overcome this limitation. The use of self-incompatibility is an alternative in hybrid breeding of oilseed rape. Unfortunately, stable self-incompatibility is recessive and phenotype-based selection is very difficult and time-consuming. The development of reliable molecular markers for detecting desirable plants with functional self-incompatible genes is of great importance for breeders and allows selection at early stages of plant growth. Because most of these reliable molecular markers are based on discrimination of class I S-locus genes that are present in self-compatible plants, there is a need to use an internal control in order to detect possible PCR inhibition that gives false results during genotyping. In this study, 269 double haploid F2 oilseed rape plants obtained by microspore embryogenesis were used to verify the applicability of an improved PCR assay based on the detection of the class I SLG gene along with an internal control. Comparative analysis of the PCR genotyping results vs. S phenotype analysis confirmed the applicability of this molecular approach in hybrid breeding programs. This approach allows accurate detection of self-incompatible plants via a different amplification profile.

This review provides a summary of haploid induction methods and factors affecting the efficacy of specific methodologies as applied to cucumber (Cucumis sativus L.), melon (Cucumis melo L.), watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai), winter squash (Cucurbita maxima Duch. ex Lam.), summer squash (Cucurbita pepo L.) and other cucurbits. This report is focused on studies that were carried out during the last 20 years.

A doubled-haploid (DH) population, obtained by anther culture of F1 plants from a cross between a highlysusceptible rice cultivar Lijiangxintuanheigu and the resistant somaclone (SC09), of the cultivar Araguaia, was used to identifyRAPD markers linked to the blast resistance gene Pi-ar. The 86 DH plants, inoculated with the race IB-9 of Magnaportheoryzae, segregated in 1:1 ratio of resistant and susceptible plants. Of the 67 primers used 31 produced DNA profiles thatdifferentiated resistant and susceptible bulks as well as the parental cultivars. The resistance gene was found linked to theprimer OPS162072 (‘AGGGGGTTCC’) at a distance of 3.6 cM. The selection efficiency of this primer was assessed in a BC3 F1population derived from another cross between a susceptible cultivar IAC 201 and SC09. The marker OPS16 showedefficiency of 86.9%, when six resistant and two susceptible plants were considered as negatives in RAPD analysis.

The objective of the study was to investigate efficiency of anther culture in the production of spontaneous double haploids from randomly selected heterozygous genotypes of wheat (Triticum aestivum L.). Anthers of 20 F1 wheat combinations were grown in vitro on a modified Potato-2 medium. All of the examined genotypes have shown the ability to produce pollen calluses as well as to regenerate green plants. On average for the whole experiment material, 47.2 calluses were produced per 100 cultured anthers. The green plant regeneration ranged from 0.8 to 13.4 green plants per spike, with an overall mean of 5.8. From the total of 582 regenerated green plants, 47.9% (279) were spontaneous double haploids. The final average yield from the study was 2.8 double haploids per spike.

Chrysanthemum is one of important ornamental species in the world. Its highly heterozygous state complicates molecular analysis, so it is of interest to derive haploid forms. A total of 2,579 non-fertilized chrysanthemum ovules pollinated by Argyranthemum frutescens were cultured in vitro to isolate haploid progeny. One single regenerant emerged from each of three of the 105 calli produced. Chromosome counts and microsatellite fingerprinting showed that only one of the regenerants was a true haploid. Nine doubled haploid derivatives were subsequently generated by colchicine treatment of 80 in vitro cultured haploid nodal segments. Morphological screening showed that the haploid plant was shorter than the doubled haploids, and developed smaller leaves, flowers and stomata. An in vitro pollen germination test showed that few of the haploid's pollen were able to germinate and those which did so were abnormal. Both the haploid and the doubled haploids produced yellow flowers, whereas those of the maternal parental cultivar were mauve. Methylation-sensitive amplification polymorphism (MSAP) profiling was further used to detect alterations in cytosine methylation caused by the haploidization and/or the chromosome doubling processes. While 52.2% of the resulting amplified fragments were cytosine methylated in the maternal parent's genome, the corresponding proportions for the haploid's and doubled haploids' genomes were, respectively, 47.0% and 51.7%, demonstrating a reduction in global cytosine methylation caused by haploidization and a partial recovery following chromosome doubling.