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Background: The rapid production of doubled haploids by anther culture technology is an important breeding method for awnless triticale. The aim of this study was to explore the effects of triticale genotype and the types and ratios of exogenous hormones in the medium on the efficiency of triticale anther culture. Results: Anthers of five triticale genotypes were cultured on four different callus induction media and the calli were induced to differentiate into green plants by culture on three different differentiation media. The triticale genotype T8004 showed the best performance in anther culture, with a callus induction rate of 28.64%, a green plantlet differentiation frequency of 33.33%, and a green plantlet production rate of 2.78%. The highest callus induction rates were obtained by culturing anthers on C3 medium (the main components were potassium nitrate, glutamine, inositol, etc.), and the highest green plantlet differentiation frequency was obtained by culturing calli on D2 differentiation medium (the main components were potassium nitrate, ammonium nitrate, calcium chloride dihydrate, etc.). Flow cytometry analyses showed that 15 of the 20 DH0 generation plants that grew normally in the field were doubled haploids. The average chromosome doubling success rate was 55.6%. Analyses of agronomic traits showed that the 11 DH1 doubled haploid plants reached the standard for awnless triticale, so they are candidate materials for breeding new awnless triticale varieties. Conclusion: The anther culture technology of triticale was optimized in this paper, which made it possible to rapidly breed homozygous varieties of awnless triticale. [ABSTRACT FROM AUTHOR]

In plant breeding studies, anther culture is used to breed hybrid varieties, to transform tetraplaid plants that can be obtained through interspecific somatic hybridization into fertile dihaploid plants, and in recent years, to obtain diploid in protoplast fusion of haploid embryogenic calli obtained from anther culture. The frequency of obtaining haploid plants in anther culture depends on many factors such as the variety, the season in which it was taken and the use of suitable media for regeneration. It was aimed to determine the most suitable regeneration medium for anther culture in Aydın Black and Kemer eggplant varieties, which are widely grown in our country. In the anther culture study, C (callus), R (regeneration) and V3 media recommended by Dumas de Valux et al. (1982) were used as nutrient media. However, as C (callus) medium, Dumas de Vaulx et al. (1982) 3 different doses of 2,4 D, Kinetin and sucrose of the C medium reported were tested. The highest plant yield (36.4%) of the Aydin Siyahı variety was obtained from the modified Dumas de Vaulx et al. (1982), from 1 mg/l 2.4-D +1 mg/l Kinetin + 120 g/l sucrose medium, the highest plant yield (33.8%) of the Kemer variety was reported by Dumas de Vaulx et al. (1982), obtained from 5 mg/l 2.4-D + 5 mg/l Kinetin + 120 g/l sucrose medium. Of the 79 plants obtained from anther culture and whose ploidy level was examined, 60 were determined as haploid, 13 as diploid, 4 as triploid, 1 as tetraploid and 1 as mixoploid. [ABSTRACT FROM AUTHOR]

In this study, an anther culture system was developed for two Citrus varieties known for their genetic value: blood orange (Moro) and mandarin (Lee). Anthers were inoculated on N6 solid medium containing thidiazuron (TDZ, 0.44 mg/L), 6-benzylaminopurine (0.8 mg/L), zeatin (0.43 mg/L), kinetin (0.44 mg/L), 1-naphthaleneacetic acid (0.2 mg/L), 2,4-Dichlorophenoxyacetic acid (0.2 mg/L), and malt extract (500 mg/L). The inoculated anthers were treated with N6 liquid medium containing spermidine (200 µM) and gibberellic acid (GA3, 1 mg/L), and cultured for 6 weeks. Thereafter, the swollen anthers were transferred to a Murashige and Skoog (MS) basal medium enriched with malt extract (500 mg/L), sucrose (50 g/L), TDZ (0.5 mg/L), GA3 (1 mg/L), and gelrite (0.2%), which induced callus and somatic embryos. These somatic embryos, from both varieties, were then transferred to a germination medium (MS basal medium containing sorbitol [0.05 M], galactose [0.05 M], malt extract [500 mg/L], GA3 [0.5 mg/L], and gelrite [2 g/L]) to develop into normal plants. However, Lee exhibited significantly slower shoot and root growth compared to Moro. Genetic analysis using barley microsatellite-derived cleaved amplified polymorphic sequence markers indicated that Lee likely originated from haploid plants, whereas Moro retained heterozygosity similar to the parent. Ploidy analysis confirmed Lee as a diploid, identical to the control. Internal transcribed spacer region analysis confirmed that Lee was an anther-cultured haploid-derived plant, estimated to be a homozygous diploid carrying recessive genes. These findings highlight potential applications in marker development for haploid-derived plants focused on recessive trait-associated phenotypes and genotypes.Key message: The doubled haploid mandarin ‘Lee’ exhibits dwarfism, as evidenced by poor elongation of new shoots, and can serve as a model to study dwarfism mechanisms in citrus species [ABSTRACT FROM AUTHOR]

Abstract Background Microspore embryogenesis is a process that produces doubled haploids in tissue culture environments and is widely used in cereal plants. The efficient production of green regenerants requires stresses that could be sensed at the level of glycolysis, followed by the Krebs cycle and electron transfer chain. The latter can be affected by Cu(II) ion concentration in the induction media acting as cofactors of biochemical reactions, indirectly influencing the production of glutathione (GSH) and S-adenosyl-L-methionine (SAM) and thereby affecting epigenetic mechanisms involving DNA methylation (demethylation—DM, de novo methylation—DNM). The conclusions mentioned were acquired from research on triticale regenerants, but there is no similar research on barley. In this way, the study looks at how DNM, DM, Cu(II), SAM, GSH, and β-glucan affect the ability of green plant regeneration efficiency (GPRE). Results The experiment involved spring barley regenerants obtained through anther culture. Nine variants (trials) of induction media were created by adding copper (CuSO4: 0.1; 5; 10 µM) and silver salts (AgNO3: 0; 10; 60 µM), with varying incubation times for the anthers (21, 28, and 35 days). Changes in DNA methylation were estimated using the DArTseqMet molecular marker method, which also detects cytosine methylation. Phenotype variability in β-glucans, SAM and GSH induced by the nutrient treatments was assessed using tentative assignments based on the Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy. The effectiveness of green plant regeneration ranged from 0.1 to 2.91 plants per 100 plated anthers. The level of demethylation ranged from 7.61 to 32.29, while de novo methylation reached values ranging from 6.83 to 32.27. The paper demonstrates that the samples from specific in vitro conditions (trials) formed tight groups linked to the factors contributing to the two main components responsible for 55.05% of the variance (to the first component DNM, DM, to the second component GSH, β-glucans, Cu(II), GPRE). Conclusions We can conclude that in vitro tissue culture conditions affect biochemical levels, DNA methylation changes, and GPRE. Increasing Cu(II) concentration in the IM impacts the metabolism and DNA methylation, elevating GPRE. Thus, changing Cu(II) concentration in the IM is fair to expect to boost GPRE.

Bacterial leaf blight (BLB), caused by Xanthomonas oryzae pv. oryzae (Xoo) is a significant disease attacking rice crops worldwide. This disease attacks at various stages of plant growth and causes significant yield loss. Breeding new varieties resistant to BLB is important to support sustainable agriculture in the future. This study aimed to identify new superior green super rice (GSR) lines resistant to BLB disease. The experiment evaluated the resistance of lowland rice lines obtained from anther culture using a factorial randomized complete block design. The 1st factor was genotype, consisting of 20 lines, 2 checks of commercial varieties (Inpari 42 Agritan GSR and Inpari 18), a resistant check (Conde), and a susceptible check (Taichung Native 1). The 2nd factor was BLB pathotypes (i.e., III, IV, and VIII). Quantitative data on disease severity and severity index were analyzed using analysis of variance and t-Dunnett test at 5% level. The results showed that the interaction between genotype and pathotype affected the disease severity and severity index in both growth phases. The tested lines exhibited varying resistance, from susceptible to resistant, to BLB. Four lines (SN 11, 13, 57, and 58) showed moderate to resistant criteria for BLB disease of 3 pathotypes in both growth phases. The selected lines can be used as a source of parents for breeders and candidates for new superior varieties with BLB resistance properties to support the reduction of synthetic chemical bactericide inputs and control BLB disease. However, further field evaluations are necessary to assess their performance.

This study aimed to enhance androgenesis efficiency protocols by identifying critical factors using artificial neural networks and multivariate sensitivity analysis. Androgenesis studies were conducted on donor tomato plants grown under different lighting regimes (LEDs and natural light). Results indicated that LED lighting significantly enhanced photomorphogenesis, photosynthesis, but also subsequent anther development being crucial for successful haploid regeneration. An androgenesis model was developed using 60 different treatments, including as inputs: genotype, lighting regime, anther stage, and medium composition. Artificial Neural Networks (ANNs) and multivariate sensitivity analysis successfully ranked the importance of those four factors, identifying plant growth regulators (PGRs) media formulation as the most critical factors. The study also confirmed spontaneous haploid genome duplication in regenerants and validated the use of flow cytometry and cytogenetic analysis for ploidy determination. These findings provide valuable and practical insights into the factors driving androgenesis, facilitating the development of more efficient, targeted and cost-effective breeding strategies, such as the production of doubled haploid tomato.Key message: Our results, utilizing ANNs and multivariate analysis, identify key factors controlling androgenesis in tomato, leading to the development of innovative procedures for a rapid, cost-effective, and efficient production of doubled haploids. [ABSTRACT FROM AUTHOR]

Background: Microspore embryogenesis is a process that produces doubled haploids in tissue culture environments and is widely used in cereal plants. The efficient production of green regenerants requires stresses that could be sensed at the level of glycolysis, followed by the Krebs cycle and electron transfer chain. The latter can be affected by Cu(II) ion concentration in the induction media acting as cofactors of biochemical reactions, indirectly influencing the production of glutathione (GSH) and S-adenosyl-L-methionine (SAM) and thereby affecting epigenetic mechanisms involving DNA methylation (demethylation—DM, de novo methylation—DNM). The conclusions mentioned were acquired from research on triticale regenerants, but there is no similar research on barley. In this way, the study looks at how DNM, DM, Cu(II), SAM, GSH, and β-glucan affect the ability of green plant regeneration efficiency (GPRE). Results: The experiment involved spring barley regenerants obtained through anther culture. Nine variants (trials) of induction media were created by adding copper (CuSO4: 0.1; 5; 10 µM) and silver salts (AgNO3: 0; 10; 60 µM), with varying incubation times for the anthers (21, 28, and 35 days). Changes in DNA methylation were estimated using the DArTseqMet molecular marker method, which also detects cytosine methylation. Phenotype variability in β-glucans, SAM and GSH induced by the nutrient treatments was assessed using tentative assignments based on the Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy. The effectiveness of green plant regeneration ranged from 0.1 to 2.91 plants per 100 plated anthers. The level of demethylation ranged from 7.61 to 32.29, while de novo methylation reached values ranging from 6.83 to 32.27. The paper demonstrates that the samples from specific in vitro conditions (trials) formed tight groups linked to the factors contributing to the two main components responsible for 55.05% of the variance (to the first component DNM, DM, to the second component GSH, β-glucans, Cu(II), GPRE). Conclusions: We can conclude that in vitro tissue culture conditions affect biochemical levels, DNA methylation changes, and GPRE. Increasing Cu(II) concentration in the IM impacts the metabolism and DNA methylation, elevating GPRE. Thus, changing Cu(II) concentration in the IM is fair to expect to boost GPRE. [ABSTRACT FROM AUTHOR]

Interspecific F1 hybrids between Asian (Oryza sativa) and African rice (Oryza glaberrima) exhibit severe sterility caused by the accumulation of hybrid sterility genes/loci at 15 or more loci. The mechanisms underlying the hybrid sterility genes are largely unknown; however, a few genes associated with the killer–protector system, which is the system most frequently associated with hybrid sterility genes, have been identified. We previously produced fertile plants as tetraploids derived from diploid interspecific F1 hybrids through anther culture; therefore, it was suggested that hybrid sterility could be overcome following tetraploidization. We investigated whether tetraploid interspecific plants produced by crossing are fertile and tested the involvement of hybrid sterility genes in the process. Fertile tetraploid interspecific F1 hybrid plants were obtained by crossing 2 tetraploids of O. sativa and O. glaberrima. To elucidate the relationships between pollen fertility and the hybrid sterility loci in the tetraploid F1 microspores, we performed genetic analyses of the tetraploid F2 hybrids and diploid plants obtained from the microspores of tetraploid interspecific hybrids by anther culture. The result suggested that the tetraploid interspecific hybrids overcame pollen and seed infertility based on the proportion of loci with the killer–protector system present in the tetraploids. The heterozygous hybrid sterility loci with the killer–protector system in the tetraploid segregate the homozygous killed allele (16.7–21.4%), with more than three-quarters of the gametes surviving. We theoretically and experimentally demonstrated that fertile rice progenies can be grown from tetraploid interspecific hybrids. [ABSTRACT FROM AUTHOR]

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The efficient doubled haploid (DH) plant production methods play a key role in accelerating the breeding of new varieties and hybrids in cultivated plants. Consequently, DH plant production methods are continuously improving for barley (Hordeum vulgare L.) breeding and research programs. Two plant regeneration (FHGR and K4NB) and three rooting media (MSr, N6I and ½N6I + Ca) were compared with four F1 barley cross-combinations to clarify the effect of medium on the regeneration of green and albino plantlets and acclimatization. The plant regeneration efficiency was higher using K4NB medium (74.53 green plantlets/100 anthers and 30.85 albino/100 anthers) compared to FHGR (55.77 green plantlets/100anthers and 21.32 albino/100 anthers). The percentage of acclimatization was highest when the K4NB regeneration medium was combined with the MSr rooting medium. Altogether, 61.83% of the anther culture-derived plantlets of 8 cross-combinations acclimatized to the greenhouse conditions, and 1403 acclimatized plantlets were produced from the F1 cross-combinations. Haploid (22.52%), diploid (69.37%) and tetraploid (8.11%) plantlets were identified among the 111 tested green plantlets by flow cytometric analyses. The tetraploid lines can be explored to offer new scopes for future barley research and breeding directions. Nearly one thousand DH plants have been integrated into our barley breeding program. [ABSTRACT FROM AUTHOR]

The article examines the effect of gamma irradiation on the survivability of anther culture derived calli of Indica rice varieties. The study analyzes the variance in the survival rate of seed derived and anther derived calli rice upon various treatments of gamma irradiation. It observes the chromosomal damage and cell wall and cell membrane damage caused by gamma irradiation, as well as the inhibition of callus growth upon higher gamma irradiation doses.

Doubled haploid (DH) production technology has been a valuable tool for the development of homozygous lines through anther culture within a short period in comparison with conventional breeding methods. Doubled haploid production in pearl millet through anther culture helps to overcome inbreeding depression which occurs due to continuous selfing for homozygous line development. We developed an efficient method to develop DH plants through anther culture in pearl millet in large numbers, which is the first report in pearl millet. The method encompasses a selection of the right stage of mother plant, optimal culture media, and influence of temperature for treatment of anther for callus induction followed by plant regeneration and flow cytometric analysis for ploidy determination. Anther culture experiments were done in proprietary pearl millet genotype of Rasi seeds '1988F1' (R × R cross) for achieving better calli or embryo induction and green plant regeneration in pearl millet. A significant frequency of 35.4% calli-embryoid response in Doubled-haploid Pearl millet Media (DPM4) was achieved at incubation temperature of 32 °C for spikes pre-treatment and anther initiation. This response was further improved to 44.4% by separating anthers from spikes on fourth day of incubation. Alteration of basal salt concentration and inclusion of 12% maltose as carbon source in calli induction media resulted in a higher number of embryo-like structures (ELS) which eventually increased the regeneration up to 12.9% in Regeneration Media (RM3). These experiments resulted in a promising procedure to develop DH plants in pearl millet to minimize the timeline for pure line development and trait introgression to accelerate breeding program. [ABSTRACT FROM AUTHOR]

• Demonstrated the correlation between morphological parameters of flower bud and microspore developmental stages in onion for the first time. • This study indicated the positive correlation between flower bud length and diameter, and anther length and diameter and microspore developmental stages. • Combination of flower bud length, diameter, and the green colour intensity of anthers was found as easily applicable, rapid, and accurate criteria for identification of microspore developmental stages. • The most reliable approach for accurate visualization of microspore stages in onion involved diluting DAPI in PBS and fixing the anthers in carnoy's fixative. Correlations between the morphological characteristics of flower buds and the developmental stages of the male gametophyte have practical implications as a reliable indicator for selecting suitable plant material for androgenesis. However, the application of androgenesis in onions has been challenging, despite extensive research on anther culture. This research paper presents findings on the associations between flower bud length and diameter, anther length and diameter, and the developmental stages of the male gametophyte across ten onion genotypes. All the morphological parameters studied in this study were positively correlated with stages of microspore development. The most responsive stages for anther culture in most of the crops are the late uninucleate and early binucleate stages. Although the bud stage and microspore development stage among the genotypes varied but this stage was typically observed in flower buds with a length of 2.5 to 3.5 mm and a diameter of 2.0 to 2.7 mm. Likewise, the late uninucleate and early binucleate stages were found in anthers with length of 1.2 to 1.6 mm and diameter of 0.55 to 0.75 mm. Additionally, we examined the utility of the aforementioned morphological parameters in identifying microspore developmental stages. Based on our results, we propose a combination of flower bud length, diameter, and the green colour intensity of anthers as easily applicable, rapid, and accurate criteria for identifying microspore developmental stages. Different methods were employed to evaluate the efficiency of DAPI staining fluorescence for visualizing microspore stages. These methods included staining with or without anther fixation, diluting DAPI in PBS with or without anther fixation, and using a combination of DAPI, EDTA, Triton X100, and PBS buffer, with or without a fixative. The study concluded that the most reliable approach involved diluting DAPI in PBS and fixing the anthers in Carnoy's fixative, providing an accurate visualisation of microspore stages. [ABSTRACT FROM AUTHOR]

Doubled haploid technology is a valuable biotechnological approach in plant breeding that enables one to quickly create new varieties through the single-stage production of homozygous lines. The aim of this study was to assess the indicators of in vitro androgenesis in the anther culture of the initial breeding material of varieties and combinations of F1 and F2 and to identify promising accessions with good responsiveness. For that purpose, the plant material that proved promising for the breeding programs of Siberian Research Institute of Plant Production and Breeding (SibRIPP&B) was used. Ten cultivars of common wheat and the F1 and F2 hybrids of nine combinations were evaluated for the main parameters of in vitro androgenesis such as the number of new formations, albino, green and all regenerated plants. Induction of androgenesis in vitro was carried out in anther culture in growth medium Chu (N6) containing 1 mg/l of growth regulator 2,4-D. The studied samples showed different responses to induction. The maximum level of new formations was found in F2 hybrids Novosibirskaya 15 × Lutescens ShT-335. The largest number of green plants was found in F1 Novosibirskaya 15 × Lutescens ShT-335. According to the results of variance analysis, a significant ( p < 0.01) influence of genotype on the studied traits was established. Varieties with good responsiveness to anther culture (Novosibirskaya 15) and lack of responsiveness to in vitro androgenesis (Novosibirskaya 31) were identified. Novosibirskaya 16 was characterized by a low regeneration capacity of new formations. A significant heterotic effect was revealed considering the number of new formations per 100 anthers among the hybrids of such combinations as Novosibirskaya 15 × Lutescens ShT-335, Novosibirskaya 15 × Lutescens 111/09, and Zagora Novosibirskaya × Obskaya 2. Novosibirskaya 15 was recommended for inclusion in crossings as a parental form that provides high hybrid responsiveness during in vitro androgenesis. The use of doubled haploid technology made it possible to quickly create DH-lines based on the breeding material.

Anther culture is a widely utilized technique in rice breeding because of its simplicity and effectiveness in rapidly obtaining pure lines in the form of doubled haploid plants. The selection of doubled haploid (DH) rice lines derived from anther culture in advanced yield trials is an important step for obtaining superior DH lines. We aimed to determine agronomic performance, including yield and yield stability in order to select lowland DH rice lines that are high yield and have good agronomic performance based on the selection index method. The research was conducted in Indonesia at three locations, i.e., Bogor (West Java), Indramayu (West Java) and Malang (East Java) from July to December 2022. The genotypes tested were 29 DH lines and three check varieties (Inpari-42 Agritan GSR, Inpari-18 Agritan and Bioni63 Ciherang Agritan) using a randomized complete block design (RCBD) with genotypes as a single factor and three replications. High heritability values are found in all agronomic characters, except the percentage of filled grain/panicle, the percentage of empty grain/panicle and productivity. The yield stability based on the Kang method showed that 15 lines were stable and had high productivity. Phenotypic correlation analysis showed that the number of productive tillers, days to flowering, days to harvesting, number of filled grains/panicle and percentage of filled grains all had positive values and significantly correlated with productivity. Phenotypic path analysis showed that the character of days to harvesting, number of filled grains/panicle, number of productive tillers and percentage of filled grains/panicle directly affected the productivity. Based on the weighted selection index, 12 DH lines were selected due to having a positive and higher index (8.54 to 0.28) than the Bioni63 Agritan and Inpari 18 check varieties. Among those lines, 9 DH lines were also stable based on the Kang Method.

Introduction Given the economic importance of growing flowers and plants in the world, the use of new technologies and methods in the improvement of ornamental plants in order to market them can play a significant role in marketing of these products and their trade in the international markets. Marigold (Tagetes spp.), is an annual and essential plant that is cultivated as an ornamental plant in many parts of the world (Neher, 1968). But in recent years, marigolds have been used as a commercial source of essential oils, biological compounds, pigments and cosmetics (Anonymous, 1976), control of malaria mosquitoes (Wanzala and Ogoma, 2013), antihypertensive, anti-inflammatory, antidepressant, antimicrobial, antimicrobial (Senatore and Feo, 1999), and control of nematode (Prasad et al., 1992). Anther or microspore culture is known to be an effective method for producing haploid plants (Henry and De Baizer, 1980). Hybrid seed production requires pure line (as a parent), and the double haploid method can reduce the production period of pure lines to 5-6 years. Production of hybrid seeds in this valuable plant is of great importance, and the double haploid method can be important in this regard. Materials and Methods In the anther culture of marigold, a culture medium containing 0.2 mg/l of Naphthalene acetic acid and 1 mg /l of 6-Benzylaminopurine was used. In this study, the effect of genotype, bud size and mannitol on androgenesis induction of marigold anthers was evaluated during two separate experiments. A factorial experiment was conducted in a completely randomized design with two factors including genotype at 5 levels (T1, T2, T3, T4, T5) and bud size at three levels (3-5, 5-10 and 10-15 mm) for first experiment. The second experiment was also performed as a factorial in a completely randomized design with 3 replications. In the recent experiment, the first factor included the method of mannitol application and the second factor included the different concentrations of mannitol (0.1, 0.2, 0.3, 0.4 and 0.5 M). The factor of application method was in 2 levels: 1: adding different concentrations of mannitol to the solid culture medium and 2: pre-treating the anthers with the liquid culture medium containing different concentrations of mannitol for 24 hours. The T4 genotype was used in the second experiment. Results In the first experiment, the effect of different bud sizes and 5 different genotypes on callus formation, mean number of shoot per anther, mean number of shoot per callus and percentage of complete plant regeneration in anther culture of marigold were studied. The results of this experiment showed that buds with the length of 5-10 mm have anthers which their microspores are at the proper growth and development stage for callogenesis and shoot production. The T3 and T4 genotypes, (both of them belonging to French species, Tagetes patula), produced the highest percentage of plant regeneration among the various cultivars. In the second experiment, we explored the impact of mannitol treatment on androgenic traits in marigold anther culture. Specifically, we examined two concentrations: 0.1 M and 0.2 M mannitol, both applied in the form of solid culture medium. Additionally, we investigated two concentrations, 0.0 M and 0.2 M mannitol, when applied as a pre-treatment in a liquid medium containing mannitol. These treatments yielded the highest percentage of callus formation. While the pre-treatment of anthers with a liquid culture medium containing 0.5 M mannitol led to the highest mean number of shoot per anther and the mean number of shoots per callus. Also, the pre-treatment with liquid medium containing 0.2 M mannitol showed the highest percentage of complete plant regeneration. Conclusion Results showed that in marigold, buds with the size of 5-10 mm contained microspores with mid-uninucleate stage to early bi-nucleate stage showed the highest response to the induction of androgenesis. Also, T3 and T4 genotypes belong to the French species showed the highest response to the regeneration. In another experiment, the pre-treatment of anthers with 0.2 and 0.5 M mannitol by using mannitol in a liquid culture medium for 24 hours, respectively showed the highest percentage of complete plant regeneration and the highest mean number of shoot per callus and anther. Chromosome counting results showed that 3 out of 5 examined plants were dihaploid and had 24 chromosomes in their root tip cells, while examined mother plants were tetraploid and showed 48 chromosomes in their root tip cells.

Marigold (Tagetes spp.) belongs to family Asteraceae, native to Mexico, is one of the most important flower crop grown commercially in different parts of India. The application of haploid techniques as anther culture can considerably accelerate marigold breeding programmes by providing homozygous doubled haploid (DH) lines for F1 hybrid seed production. Therefore, the objective of the present investigation was to study the effect of growth regulators for in vitro regeneration in both African marigold and French marigold genotypes viz., Pusa Basanti Gainda and Pusa Arpita, respectively for haploid induction. Among the different treatments tested for callus induction, anthers cultured on MS medium supplemented with 1.0 mg/l BAP + 1.0 mg/l 2,4-D + 45 g/l sucrose significantly induced highest (38.74%) callus in the shortest period of time (16 days). Among two genotypes tested, embryogenic callus induction (27.70%) was significantly higher in Pusa Arpita over Pusa Basanti Gainda (23.37%). Among the different regeneration treatments, the highest adventitious shoot bud induction (13.32%), maximum (1.09) number of buds/callus in shortest duration (19.47 days) was observed in anther derived callus cultured on MS medium supplemented with 2.0 mg/l BAP + 0.5mg/l NAA + 30 g/l sucrose. Among two genotypes evaluated for shoot bud induction, maximum (3.81%) regeneration was recorded in Pusa Arpita over Pusa Basanti Gainda (2.90%). In French genotype, the whole regeneration process was completed in 30 days whereas in African genotype it took nearly 40 days. This rapid regeneration system from anthers is highly useful in inducing haploids and di-haploids in African and French marigold lines, respectively.

Glycine max (L.) Merr. (soybean) is a multi-purpose crop used for both animal and human feed. It is an economically and industrially important crop. It possesses many therapeutical and nutraceutical compounds. Therefore, soybean is referred to as 'Gold from the soil'. Conventional breeding approaches are laborious and time-consuming. Thus, alternative biotechnological methods, such as in vitro micropropagation, regeneration, and transformation, could be advantageous. Despite the efforts made in the field of soybean micropropagation for haploidy and doubled haploidy, especially androgenesis, the success rate accounts for only approximately 2%. Androgenesis in soybean is lacking primarily due to its recalcitrant nature and differences in the development of microspores within a flower. Haploids and doubled haploids (DHs) have contributed immensely to crop improvement programs. In this review, soybean androgenesis history, production of haploids, and doubled haploids have been highlighted. The factors responsible for the androgenic responses have also been discussed. Furthermore, the review will be helpful in understanding the challenges in the standardization of protocol for the production of haploids and DHs in soybean, which will eventually assist breeding and crop improvement. [ABSTRACT FROM AUTHOR]

To keep pace with the skyrocketing demand of vegetable oil and reduced dependency on import, there is a need to focus on indigenous oilseed crops, such as niger (Guizotia abyssinica L.F. Cass). Niger is a minor oilseed crop that consists of 32 to 40% quality oil and 18 to 24% protein in the seeds. Despite its considerable importance, self-incompatibility and high outcrossing pose difficulty in breeding through conventional methods. Double haploid (DH) technology is one of the alternatives to overcome the problem and develop inbred lines in a shorter time. In context to this, a highly efficient protocol for DH production through anther culture in Indian niger varieties JNS 9 and JNS 28 was developed. The investigation was conducted to identify the suitable microspore stage for anther culture, cold pre-treatment, hormonal combinations for callus induction (T1–T4), shooting (S1–S26), rooting (R1–R3), hardening, ploidy index, and the effect of different colchicine treatments on the efficiency of the developed protocol. Anthers in disc florets of light green to greenish yellow color have uninucleate microspores (7 d of bud initiation). For callus initiation, Murashige and Skoog (MS) medium containing 2.0 mg L−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.3 mg L−1 kinetin (KIN) showed 100% efficiency. For shoot initiation, 37 to 40% greening was observed on MS medium with 0.5 mg L−1 6-benzylaminopurine (BAP) and 0.5 mg L−1 activated charcoal and, subsequently, 19% shoot emergence on MS medium containing 0.5 mg L−1 BAP and 0.5 mg L−1 KIN. Low efficiency of shoot regeneration was addressed by adding 0.2% colchicine for 30 h at the callusing stage which resulted in 90 to 95% increased efficiency in shooting. For rooting, MS medium containing 2.0 mg L−1 indole-3-butyric acid (IBA) was efficient with a frequency of 85 to 90% followed by hardening in 1:1:1 ratio of vermiculite:sand:soil in pots. Ploidy indexing was done using cell size analysis followed by chromosome count using a microscope which confirmed the ploidy level of regenerants as compared to diploid control. Thus, the procedure developed in the study demonstrates the successful development of DH which in turn facilitates the acceleration of the breeding program through the development of homozygous inbreds and new cultivars. [ABSTRACT FROM AUTHOR]

In order to optimize the Japonica rice anther culture system and improve the anther culture efficiency of Japonica rice hybrid combinations, two carbon sources maltose and sucrose were selected in this study to set up induction medium of different treatments for anther culture of 10 Japonica rice F4 hybrid combinations. The results showed that the induction medium with sucrose was more effective than maltose in Japonica rice anther culture. Then six Japonica rice hybrid combinations of different generations were cultured with optimized callus induction medium, in which combination J118 showed better callus induction rate (9. 90%) and green seedling differentiation rate (14.48%), and the highest anther culture ability (1.43%). Therefore, J118 was a hybrid combination with strong regeneration ability in anther culture, which could be used as the basic material suitable for haploid breeding, gene mapping and cloning, genetic transformation research. It was of great significance to improve the efficiency of anther culture breeding and accelerate the breeding of new varieties. [ABSTRACT FROM AUTHOR]

Doubled haploid (DH) plants have been widely used for breeding and biological research in crops. Populus spp. have been used as model woody plant species for biological research. However, the induction of DH poplar plants is onerous, and limited biological or breeding work has been carried out on DH individuals or populations. In this study, we provide an effective protocol for poplar haploid induction based on an anther culture method. A total of 96 whole DH plant lines were obtained using an F1 hybrid of Populus simonii × P. nigra as a donor tree. The phenotypes of the DH population showed exceptionally high variance when compared to those of half-sib progeny of the donor tree. Each DH line displayed distinct features compared to those of the other DH lines or the donor tree. Additionally, some excellent homozygous lines have the potential to be model plants in genetic and breeding studies. [ABSTRACT FROM AUTHOR]

Anther culture is one of the most popular methods for obtaining haploid triticale plants. The current paper has presented the study results of the efficiency of the method for obtaining haploid plants in promising winter triticale forms bred by the Federal Agricultural Research Center of South-East. There has been estimated haploproduction parameters for the studied genotypes on the nutrient media C-17 and P-2. There were no genotypes unresponsive to androgenesis. There has been found that the medium Potato-2 had a significant positive effect on the total number of embryogenic structures per 100 cultivated anthers in four of the six studied genotypes when the index increased in 1–3 times. The mean value of the EC/100KP indicator was 23.3 with a variation of 6.4-75.1. The largest number of ES (45.8 and 75.1) was found in genotype No. 96 (F5 Zimogor/win.br.wheat L.39) on induction media C-17 and P-2. The genotypes No. 95 and No. 97 were characterized by the lowest indicators F4 DH13/ win.br.wheat ‘Atkara’//Vodoley/ADP-2///Colina and F5 MAG/Vodoley//TI-17. Plant regeneration varied from 3.4 to 22.1 with an average value of 12.6 per 100 EC. The mean number of green plants per 100 EC was 3.9, varying from 0.4 to 12.1. The proportion of green plants, depending on the genotype, varied from 5.0 to 76.9 %. Two-way analysis of variance has identified the dominant role of the genotype at all stages of haploproduction. The proportion of effect of the nutrient medium was statistically significant, but insignificant in comparison with the genotype. There has been established that, along with genotypic dependence and albinism, the limiting factor of the method is a low frequency of regeneration of embryo-like structures. In total, there were obtained 949 regenerated plants out of 7538 embryogenic structures, of which 326 were green. The ratio of green plants to albinos was 1:2.

The efficient doubled haploid (DH) plant production methods play a key role in accelerating the breeding of new varieties and hybrids in cultivated plants. Consequently, DH plant production methods are continuously improving for barley (Hordeum vulgare L.) breeding and research programs. Two plant regeneration (FHGR and K4NB) and three rooting media (MSr, N6I and ½N6I + Ca) were compared with four F1 barley cross-combinations to clarify the effect of medium on the regeneration of green and albino plantlets and acclimatization. The plant regeneration efficiency was higher using K4NB medium (74.53 green plantlets/100 anthers and 30.85 albino/100 anthers) compared to FHGR (55.77 green plantlets/100anthers and 21.32 albino/100 anthers). The percentage of acclimatization was highest when the K4NB regeneration medium was combined with the MSr rooting medium. Altogether, 61.83% of the anther culture-derived plantlets of 8 cross-combinations acclimatized to the greenhouse conditions, and 1403 acclimatized plantlets were produced from the F1 cross-combinations. Haploid (22.52%), diploid (69.37%) and tetraploid (8.11%) plantlets were identified among the 111 tested green plantlets by flow cytometric analyses. The tetraploid lines can be explored to offer new scopes for future barley research and breeding directions. Nearly one thousand DH plants have been integrated into our barley breeding program.

Climate change can trigger submergence stress, which has an impact on decreasing rice yield and causing crop failure. This needs to be overcome with a sustainable approach, such as breeding doubled-haploid (DH) rice varieties that are adaptive to these stresses. However, it requires a systematic screening approach to solve it. Therefore, this study aimed to select DH rice lines that are tolerant and adaptive through systematic submergence screening and their stability; (2) to identify the effectiveness of both submergence screening environments. The study was carried out in three locations: the greenhouse of ICRR-Muara Bogor, the ICRR-Sukamandi Field Experimental Station, and the IPB-Sawah Baru Experimental Station. The first experiment was conducted in ICRR-Muara using a randomized complete block design (RCBD), with genotype as a factor, consisting of 56 doubled-haploid lines, four commercial varieties, and two check varieties (tolerant and sensitive). Seven selected genotypes representing tolerant, moderate, sensitive, and check groups were transferred into pots in Sawah Baru Experimental Station to be evaluated for agronomic and tolerance responses using the RCBD split-plot design. The second experiment was carried out to validate the stability of tolerance traits in doubled-haploid lines. The trial and the process of the second experiment were like the first experiment (clear water). However, the submergence in the second experiment was conducted using muddy water. The experimental results showed that the screening of concrete pools was effective in determining sensitive lines in large populations. Meanwhile, screening in the pond with muddy water was better in identifying the effect of submergence stress on agronomic and yield characteristics. Based on screening, F13, F14, F15, and F19 are adaptive doubled haploid lines under the systematic screening of submergence stress and have been evaluated for their adaptive and tolerance stability. Therefore, they can be recommended for preliminary yield tests.

Anther culture (AC) is a valuable technique in rice breeding. However, the genetic mechanisms underlying anther culturability remain elusive, which has hindered its widespread adoption in rice breeding programs. During AC, microspores carrying favorable alleles for AC are selectively regenerated, leading to segregation distortion (SD) of chromosomal regions linked to these alleles in the doubled haploid (DH) population. Using the AC method, a DH population was generated from the japonica hybrid rice Shenyou 26. A genetic map consisting of 470 SNPs was constructed using this DH population, and SD analysis was performed at both the single- and two-locus levels to dissect the genetic basis underlying anther culturability. Five segregation distortion loci (SDLs) potentially linked to anther culturability were identified. Among these, SDL5 exhibited an overrepresentation of alleles from the female parent, while SDL1.1, SDL1.2, SDL2, and SDL7 displayed an overrepresentation of alleles from the male parent. Furthermore, six pairs of epistatic interactions (EPIs) that influenced two-locus SDs in the DH population were discovered. A cluster of genetic loci, associated with EPI-1, EPI-3, EPI-4, and EPI-5, overlapped with SDL1.1, indicating that the SDL1.1 locus may play a role in regulating anther culturability via both additive and epistatic mechanisms. These findings provide valuable insights into the genetic control of anther culturability in rice and lay the foundation for future research focused on identifying the causal genes associated with anther culturability. [ABSTRACT FROM AUTHOR]

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Background: The microspores of five tropical japonica and five indica rice genotypes were subjected to androgenic studies. The effect of growth regulators on callus induction were studied to improve the anther culture efficiency. Methods: The cold pre-treatment of panicles at 10℃ were done at different days of intervals viz., 5, 8, 10 and 12 days. The microspores at uninucleate stage were selected and dusted after pre-treatment. The anthers were cultured in N6 basal media supplemented with casein hydrolysate (250 mg/L), proline (250 mg/L), silver nitrate (100 mg/L), maltose (50 g/L) and growth regulators. Result: The 8 days of cold pre-treatment initiated calli in most of the ten genotypes. The days taken for callus induction varied with genotype from 32-55 days. The callus induction frequency ranged from 1.41 to 5.12%. The responsive genotypes (Azucena, Palawan, Nira) on callus induction were studied for their regeneration potential. [ABSTRACT FROM AUTHOR]

In cereal breeding, in vitro androgenesis methods are frequently applied to achieve doubled haploid (DH) plants. The aim of this study was to determine the effects of genotype (three registered varieties and eight F1 crossing combinations) and induction medium (W14mf and P4mf) on anther cultures (ACs) of triticale (×Triticosecale Wittmack). Androgenesis was induced in the treatment of each tested genotype, and the genotype significantly influenced the efficiency of AC, including in embryo-like structures (ELSs), albinos, green plantlets, and transplanted plantlets. The utilized medium also had a significant effect on the number of ELSs, albinos, and transplanted plantlets. Both media were suitable for AC in triticale DH plant production. The efficiency of AC was higher when using the P4mf medium (103.7 ELS/100 anthers, 19.7 green plantlets/100 anthers) than when using the W14mf medium (90.0 ELS/100 anthers, 17.0 green plantlets/100 anthers). However, the green plantlet regeneration efficiency of microspore-derived structures was 18.0% when using the W14mf medium, while this value was 15.9% in the case of ELSs induced with the P4mf medium. After nursery seed evaluation and propagation (DH1), the genetic homogeneity of the offspring generation (DH2) was tested using a molecular genetic method. Most of the tested DH lines showed homogeneity and were progressed into a breeding program after agronomic selection. Some DH lines showed inhomogeneity, which could be explained by the outcross inclination of triticale. We would like to call breeders' attention to the outcross character of triticale and emphasize the vigilant propagation and maintenance of the triticale DH lines in breeding programs. Due to the outcross nature of triticale, even in self-pollinated genotypes, breeders should focus on careful maintenance, along with isolation in the case of line propagations, in triticale breeding programs. [ABSTRACT FROM AUTHOR]

Rice blast caused by Magnaporthe oryzae is one of the most serious rice diseases worldwide. The early indica rice thermosensitive genic male sterile (TGMS) line HD9802S has the characteristics of stable fertility, reproducibility, a high outcrossing rate, excellent rice quality, and strong combining ability. However, this line exhibits poor blast resistance and is highly susceptible to leaf and neck blasts. In this study, backcross introduction, molecular marker-assisted selection, gene chipping, anther culture, and resistance identification in the field were used to introduce the broad-spectrum blast-resistance gene R6 into HD9802S to improve its rice blast resistance. Six induction media were prepared by varying the content of each component in the culture medium. Murashige and Skoog's medium with 3 mg/L 2,4-dichlorophenoxyacetic acid, 2 mg/L 1-naphthaleneacetic acid, and 1 mg/L kinetin and N6 medium with 800 mg/L casein hydrolysate, 600 mg/L proline, and 500 mg/L glutamine could improve the callus induction rate and have a higher green seedling rate and a lower white seedling rate. Compared to HD9802S, two doubled haploid lines containing R6 with stable fertility showed significantly enhanced resistance to rice blast and no significant difference in spikelet number per panicle, 1000-grain weight, or grain shape. Our findings highlight a rapid and effective method for improving rice blast resistance in TGMS lines. [ABSTRACT FROM AUTHOR]

Background: Okra [Abelmoschus esculentus (L.) Moench.] is a nutrient-rich vegetable crop widely grown in the tropics and subtropics mainly for its edible pods. The haploid technique has been used in plant breeding for the improvements of plants and to develop new varieties in relatively a short time. Hence, we have optimized several factors such as plant growth regulators (PGR), sucrose concentration, cold treatment, type of media and culture conditions for callus induction from the anther and ovary of okra (557 F1 hybrid). Methods: The flower buds of different sizes were collected to determine various stages of development and then subjected to cold pretreatments. The explants were then cultured on various combinations of PGRs i.e., naphthyloxy acetic (NOA), Indole acetic acid (IAA), 2, 4-Dichlorophenoxy acetic acid (2, 4-D), Benzyl amino purine (BAP), isopentenyl adenine 2iP, Kinetin (KIN) and Thidiazuron (TDZ). Result: The optimum developmental stage of microspore for callus initiation was achieved from flower buds of okra and its size was about 11 mm long. Flower buds that emerged one week after the flowering showed significantly higher percentage of callus induction. The optimum stage for ovary and ovule culture were one or two days prior to anthesis and the flower buds stage was 35±1mm. In conclusion, our study investigated the effect of several factors that affects callus induction in okra and optimized cultured conditions for future haploid development for okra. [ABSTRACT FROM AUTHOR]

Anther culture is a widely utilized technique in rice breeding because of its simplicity and effectiveness in rapidly obtaining pure lines in the form of doubled haploid plants. The selection of doubled haploid (DH) rice lines derived from anther culture in advanced yield trials is an important step for obtaining superior DH lines. We aimed to determine agronomic performance, including yield and yield stability in order to select lowland DH rice lines that are high yield and have good agronomic performance based on the selection index method. The research was conducted in Indonesia at three locations, i.e., Bogor (West Java), Indramayu (West Java) and Malang (East Java) from July to December 2022. The genotypes tested were 29 DH lines and three check varieties (Inpari-42 Agritan GSR, Inpari-18 Agritan and Bioni63 Ciherang Agritan) using a randomized complete block design (RCBD) with genotypes as a single factor and three replications. High heritability values are found in all agronomic characters, except the percentage of filled grain/panicle, the percentage of empty grain/panicle and productivity. The yield stability based on the Kang method showed that 15 lines were stable and had high productivity. Phenotypic correlation analysis showed that the number of productive tillers, days to flowering, days to harvesting, number of filled grains/panicle and percentage of filled grains all had positive values and significantly correlated with productivity. Phenotypic path analysis showed that the character of days to harvesting, number of filled grains/panicle, number of productive tillers and percentage of filled grains/panicle directly affected the productivity. Based on the weighted selection index, 12 DH lines were selected due to having a positive and higher index (8.54 to 0.28) than the Bioni63 Agritan and Inpari 18 check varieties. Among those lines, 9 DH lines were also stable based on the Kang Method. [ABSTRACT FROM AUTHOR]

Hot pepper ranks seventh among the most produced vegetables in the world. This crop is famous for its color and pungency. Hot pepper contains many important phytonutrients that enable it to fight against cancer. Conventional breeding in Hot Pepper is labor-consuming and a long-term process. This can be overcome by using novel approaches, such as, in vitro doubled haploid plant production. This method not only accelerate breeding programs but also facilitates recovery of recessive mutations. There are many articles published on doubled haploid development in Capsicum annuum; it reports both anther culture and shed-microspore culture methods, but both these methods require either subculture of anthers or the addition of new media, which makes both protocols laborious. The present study aims to develop a single-step direct embryogenesis protocol to produce doubled haploids in Capsicum annuum. We analyzed effectiveness of microspore embryogenesis on ten Hot pepper genotypes with six media combinations including shed-microspore culture protocol (Supena et.al 2006) and two-step anther culture protocol (Dumas de vaulx et.al 1981 and Para-Vega et.al 2016). Among six, one media combination responded very well to single-step direct embryogenesis compared to other protocols with more than 20 % plant regeneration frequency. We observed an average embryogenesis of 7.53% and plant regeneration frequency of 3.81%. We achieved a survival index of 97.61% after acclimatization of plants in the polyhouse. The results of these experiments show that, one-step direct embryogenesis can be achieved with unique combination of plant growth regulators. [ABSTRACT FROM AUTHOR]

Anther culture is the most effective and not technically complex tool for obtaining double wheat haploids. The current study is devoted to the research of the influence of the genotype and concentration of the growth regulator 2.4-D on the efficiency of androgenesis in vitro of spring bread wheat. The purpose of the study was to estimate the efficiency of the anther culture of hybrids of the first and second generation and their parental varieties and to study its dependence on different concentrations of the growth regulator 2.4-D. There has been carried out the estimation of the traits of the F1 hybrids, the F2 population, and the parental varieties ‘Obskaya 2’ and ‘Novosibirskaya 15’ when 2.4-D was added to the induction medium at a concentration of 1 and 2 mg/l. There has been established that the F2 population and the parental variety ‘Novosibirskaya 15’ are characterized by the largest indicators. The average values were significantly surpassed by the F2 population in the traits ‘number of productive anthers per 100 anthers’ and ‘number of all regenerants per 100 anthers’ at 1 mg/l of 2.4-D. The variety ‘Novosibirskaya 15’ surpassed the average values in traits ‘number of sprouts per 100 anthers’ and ‘number of all regenerants per 100 sprouts’ at 2 mg /l of 2.4-D. The trial has shown that the best responsiveness of the anther culture for the studied genotypes was when the growth regulator 2.4-D was added to the induction medium at a concentration of 1 mg/l. The variety ‘Novosibirskaya 15’ has been characterized by good responsiveness in anther culture in vitro and could be used as a donor of valuable alleles in wheat breeding programs using DH technologies.

Bounteous modern and innovative biotechnological tools have resulted in progressive development in the barley breeding program. Doubled haploids developed (homozygous lines) in a single generation is significant. Since the first discovery of haploid plants in 1920 and, in particular, after discovering in vitro androgenesis in 1964 by Guha and Maheshwari, the doubled haploidy techniques have been progressively developed and constantly improved. It has shortened the cultivar development time and has been extensively used in: genetic studies, gene mapping, marker/trait association, and QTL studies. In barley, the haploid occurrence developed gradually from being a sporadic and random process (spontaneous) to haploid development by in vivo method of modified pollination or by in vitro culture of immature male or female gametophytes. Although significant improvement in DH induction protocols has been made, challenges still exist for improvement in areas such as: low efficiency, albinism, genotypic specificity etc. Here, the paper focuses on: haploidization via different in vitro, in vivo techniques, the recent advances technologies like centromere‐mediated haploidization, hap induction gene, and Doubled haploid CRISPR. The au-courant work of different researchers in barley using these technologies is reviewed. Studies on different factors affecting haploid induction and work on genome doubling of barley haploids to produce DH lines via spontaneous and induced technologies has also been highlighted. [ABSTRACT FROM AUTHOR]

Catharanthus roseus L. (G.) Don is the most widely studied plant because of its high pharmacological value. In vitro culture uses various plant parts such as leaves, nodes, internodes and roots for inducing callus and subsequent plant regeneration in C. roseus. However, till now, little work has been conducted on anther tissue using plant tissue culture techniques. Therefore, the aim of this work is to establish a protocol for in vitro induction of callus by utilizing anthers as explants in MS (Murashige and Skoog) medium fortified with different concentrations and combinations of PGRs. The best callusing medium contains high α-naphthalene acetic acid (NAA) and low kinetin (Kn) concentrations showing a callusing frequency of 86.6%. SEM–EDX analysis was carried out to compare the elemental distribution on the surfaces of anther and anther-derived calli, and the two were noted to be nearly identical in their elemental composition. Gas chromatography–mass spectrometry (GC–MS) analysis of methanol extracts of anther and anther-derived calli was conducted, which revealed the presence of a wide range of phytocompounds. Some of them are ajmalicine, vindolinine, coronaridine, squalene, pleiocarpamine, stigmasterol, etc. More importantly, about 17 compounds are exclusively present in anther-derived callus (not in anther) of Catharanthus. The ploidy status of anther-derived callus was examined via flow cytometry (FCM), and it was estimated to be 0.76 pg, showing the haploid nature of callus. The present work therefore represents an efficient way to produce high-value medicinal compounds from anther callus in a lesser period of time on a larger scale. [ABSTRACT FROM AUTHOR]

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.

Anther culture is an efficient biotechnological tool in modern plant breeding programs to produce new varieties and parental lines in hybrid seed productions. However, some bottlenecks—low induction rate, genotype dependency, albinism—restrict the widespread utilization of in vitro anther culture in rice breeding, especially in Oryza sativa ssp. indica (indica) genotypes, while an improved efficient protocol can shorten the process of breeding. Three different induction media (N6NDK, N6NDZ, Ali-1) and four plant regeneration media (mMSNBK1, MSNBK3, MSNBKZ1, MSNBKZ2) were tested with five indica rice genotypes to increase the efficiency of in vitro androgenesis (number of calli and regenerated green plantlets). The production of calli was more efficient on the N6NDK medium with an average 88.26 calli/100 anthers and N6NDZ medium with an average of 103.88 calli/100 anthers as compared to Ali-1 with an average of 6.96 calli/100 anthers. The production of green plantlets was greater when calli was produced on N6NDK medium (2.15 green plantlets/100 anthers) compared when produced on to N6NDZ medium (1.18 green plantlets/100 anthers). Highest green plantlets production (4.7 green plantlets/100 anthers) was achieved when mMSNBK1 plant regeneration medium was used on calli produced utilizing N6NDK induction medium. In the best overall treatment (N6NDK induction medium and mMSNBK1 plant regeneration medium), four tested genotypes produced green plantlets. However, the genotype influenced the efficiency, and the green plantlets production ranged from 0.4 green plantlets/100 anthers to 8.4 green plantlets/100 anthers. The ploidy level of 106 acclimatized indica rice plantlets were characterized with flow cytometric analyses to calculate the percentage of spontaneous chromosome doubling. Altogether, 48 haploid-, 55 diploid-, 2 tetraploid- and 1 mixoploid plantlets were identified among the regenerant plantlets, and the spontaneous chromosome doubling percentage was 51.89%. Utilization of DH plants have been integrated as a routine method in the Hungarian rice breeding program. The tetraploid lines can be explored for their potential to offer new scopes for rice research and breeding directions in the future. [ABSTRACT FROM AUTHOR]

Objective. As the primary means of plant-induced haploid, anther culture is of great significance in quickly obtaining pure lines and significantly shortening the potato breeding cycle. Nevertheless, the methods of anther culture of tetraploid potato were still not well established. Methods. In this study, 16 potato cultivars (lines) were used for anther culture in vitro. The corresponding relation between the different development stages of microspores and the external morphology of buds was investigated. A highly-efficient anther culture system of tetraploid potatoes was established. Results. It was shown in the results that the combined use of 0.5 mg/L 1-Naphthylacetic acid (NAA), 1.0 mg/L 2,4-Dichlorophenoxyacetic acid (2,4-D), and 1.0 mg/L Kinetin (KT) was the ideal choice of hormone pairing for anther callus. Ten of the 16 potato cultivars examined could be induced callus with their respective anthers, and the induction rate ranged from 4.44% to 22.67% using this hormone combination. According to the outcome from the orthogonal design experiments of four kinds of appendages, we found that the medium with sucrose (40 g/L), AgNO3 (30 mg/L), activated carbon (3 g/L), potato extract (200 g/L) had a promotive induction effect on the anther callus. In contrast, adding 1 mg/L Zeatin (ZT) effectively facilitated callus differentiation. Conclusion. Finally, 201 anther culture plantlets were differentiated from 10 potato cultivars. Among these, Qingshu 168 and Ningshu 15 had higher efficiency than anther culture. After identification by flow cytometry and fluorescence in situ hybridization, 10 haploid plantlets (5%), 177 tetraploids (88%), and 14 octoploids (7%) were obtained. Some premium anther-cultured plantlets were further selected by morphological and agronomic comparison. Our findings provide important guidance for potato ploidy breeding. [ABSTRACT FROM AUTHOR]

Two different androgenesis pathways, including shed-microspore culture (SMC) and anther culture (AC), were developed for haploid induction in four mutagenized M1 rice cultivars. The effect of gum arabic (GA), plant growth regulators, cold shock, culture medium, carbohydrate source, and genotype were evaluated in both induction and regeneration phases in both methods. The SMC method is reported for the first time in rice. In AC pathway, the highest number of regenerated embryos was obtained in MS medium supplemented with 2 mg/L Kinetin + 1 mg/L NAA + 10 mg/L GA. In SMC pathway, the highest number of regenerated embryos was obtained with 3% maltose and 10 mg/L GA in the upper medium and the activated charcoal in the lower medium. The average number of regenerated embryos in SMC was more than the AC pathway. Haploid plants were confirmed by chromosome counting and flow cytometry analysis. The highest percent of haploid plantlets was obtained in SMC of Hashemi cultivar. These protocols can be utilized to develop successful haploids induction in rice. Completely homozygous doubled haploid lines, subsequent to chromosome doubling, could be useful in mutation and selection breeding programs. [ABSTRACT FROM AUTHOR]

The induction of haploid cell development into normal plants enables the production of doubled haploid lines, which are homozygous and can be used in breeding programs as an alternative to conventionally derived inbred lines. In this paper, we present the historical background and current status of the attempts of haploid induction in carrot (Daucus carota L.). Economically, carrot is one of the most important vegetables. It is an outcrossing diploid (2n = 2x = 18) species. Nowadays, the seeds of hybrid cultivars constitute the majority of the carrot seeds sold in the world. Hybrid cultivars of carrot are produced using inbred populations. Inbreeding in this species is difficult due to an inbreeding depression and is also time-consuming, as it is a biennial crop. Therefore, the implementation of the haploidization technology into the breeding programs of carrot is of high interest. Androgenesis, gynogenesis and induced parthenogenesis are the methods that have been used for haploid induction, and their potential in haploidization of carrot is discussed. The centromere-specific histone 3 variant (CENH3) and its manipulation in carrot is also acknowledged. [ABSTRACT FROM AUTHOR]