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Twenty-one quantitative trait loci were discovered across six environments, including three (NS), seven (LS) and eleven (VLS) conditions. The linkage groups 1A, 1B, 2A, 2B, 2D, 3B, 4A, 6A, 6B and 7D spanned quantitative trait loci (QTLs). For canopy temperature (CT), a stable QTL (Qct_rpcau_4A) in the environment E6 has shown a phenotypic variance (PVE) up to 17.85%. The QTL, Qspad_rpcau_2D, was found to be stable for SPAD value, explaining the PVE of 15.05%. Whereas, three stable QTLs viz. Qgy_rpcau_3B, Qgy_rpcau_4A and Qgy_rpcau_6A were associated with the chromosomes 3B, 4A and 6B explaining a PVE of 20.85%, 17.43% and 17.37% respectively for the trait GY. The interaction of genotype and environment has been shown to be useful in determining the best lines for heat-stressed environments. In addition, G X E analysis was performed on the population. In the ranking of genotypes for both mean yield and mean vs. stability, GGE biplot across the six environments, DH 146, 195, 60, 202, 65, 155, 124, 5, 201, 169, 15 and 170 were ranked closest to ideal and winning genotype; these were highly adapted and most stable lines. The goal of the current investigation was to find the best suitable double haploid lines which can withstand heat stress and to find those QTLs which are influential to heat stress for the studied traits. [ABSTRACT FROM AUTHOR]

Breeders are turning to rapid breeding methods in order to respond to the increasing population for the breeding of the wheat plant, which has a very important place in human nutrition. One of the biotechnological methods to shorten wheat breeding, which takes 15-20 years with classical breeding methods, is double haploid. The aim of this study is to obtain double haploid lines by taking wheat genotypes that have reached the F2 generation after hybridization into anther culture and thus shorten the breeding period. When looking at the response to anther culture of the 15 different F2 combinations used in the study, F2-7 and F2-10 genotypes stood out as the most successful genotypes. It was observed that 4 different groups were formed among 15 genotypes according to the success rate. It was concluded that the success of anther culture varies depending on the genotypes used, the nutrient media and the suitability of laboratory conditions. [ABSTRACT FROM AUTHOR]

Rapeseed is a significant global source of plant oil. Silique size, particularly silique length (SL), impacts rapeseed yield. SL is a typical quantitative trait controlled by multiple genes. In our previous study, we constructed a DH population of 178 families known as the 158A-SGDH population. In this study, through SL QTL mapping, we identified twenty-six QTL for SL across five replicates in two environments. A QTL meta-analysis revealed eight consensus QTL, including two major QTL: cqSL.A02-1 (11.32–16.44% of PVE for SL), and cqSL.C06-1 (10.90–11.95% of PVE for SL). Based on biparental resequencing data and microcollinearity analysis of target regions in Brassica napus and Arabidopsis, we identified 11 candidate genes at cqSL.A02-1 and 6 candidate genes at cqSL.C06-1, which are potentially associated with silique development. Furthermore, transcriptome analysis of silique valves from both parents on the 14th, 21st, and 28th days after pollination (DAP) combined with gene function annotation revealed three significantly differentially expressed genes at cqSL.A02-1, BnaA02G0058500ZS, BnaA02G0060100ZS, and BnaA02G0060900ZS. Only the gene BnaC06G0283800ZS showed significant differences in parental transcription at cqSL.C06-1. Two tightly linked insertion-deletion markers for the cqSL.A02-1 and cqSL.C06-1 loci were developed. Using these two QTL, we generated four combinations: A02SGDH284C06158A, A02SGDH284C06SGDH284, A02158AC06158A, and A02158AC06SGDH284. Subsequent analysis identified an ideal QTL combination, A02158AC06SGDH284, which exhibited the longest SL of this type, reaching 6.06 ± 0.10 cm, significantly surpassing the other three combinations. The results will provide the basis for the cloning of SL-related genes of rapeseed, along with the development of functional markers of target genes and the breeding of rapeseed varieties. [ABSTRACT FROM AUTHOR]

The production of double haploids ("DH") by microspore-derived embryos is one of the best breeding methods to generate new varieties with better traits and stable genetic background. In the previous study, radish 'DH' lines were generated with a different range of glucosinolate (GSL) contents, ranging from low to high levels of GSL. In this study, we performed metabolic and transcriptional profiling to elucidate the regulatory system behind the GSL biosynthesis process using the 'DH' radish lines. Four individual 'DH' lines were selected, of which two lines named 'HH' had high GSL content, while the other two lines, 'LL', had low GSL content. HPLC analysis in the vegetative (leaf and root) and reproductive tissue (seed) was detected seven GSL compounds from radish. Among seven GSLs, glucoraphasatin (GRH) occupied the largest proportion of total GSLs in both leaf and root tissues, while glucoraphenin (GRE) was taking a place as the major GSL in radish seeds. Six major genes (RsBCAT4, RsIPMDH1, RsCYP79F1, RsCYP83A1, RsUGT74B1, and RsGRS1) representing the major biosynthesis of aliphatic GSLs were selected for qRT-PCR analysis. Heat map analysis based on Pearson correlation coefficient showed that RsBCAT4, RsIPMDH1, RsCYP79F1, and RsCYP83A1 were positively correlated with the amount of GRH in leaf tissue. Meanwhile, RsGRS1 showed a strong correlation with the amount of GRH and total aliphatic GSLs in both leaf and root tissues. By using the 'DH' radish lines, this study revealed that regardless of tissues of radish, accumulation of total GSL is strongly affected by the RsGRS1 and also positively supported by the other biosynthetic genes like RsBCAT4, RsIPMDH1, RsCYP79F1, and RsCYP83A1. [ABSTRACT FROM AUTHOR]

Sweetpotato (Ipomoea batatas L.) is a strategic crop with both economic and energy value. However, improving sweetpotato varieties through traditional breeding approaches can be a time-consuming and labor-intensive process due to the complex genetic nature of sweetpotato as a hexaploid species (2n = 6x = 90). Double haploid (DH) breeding, based on in vivo haploid induction, provides a new approach for rapid breeding of crops. The success of haploid induction can be achieved by manipulating specific genes. Two of the most critical genes, DMP (DUF679 membrane proteins) and MTL (MATRILINEAL), have been shown to induce haploid production in several species. Here, we identified and characterized DMP and MTL genes in sweetpotato using gene family analysis. In this study, we identified 5 IbDMPs and 25 IbpPLAs. IbDMP5 and IbPLAIIs (IbPLAIIκ, IbPLAIIλ, and IbPLAIIμ) were identified as potential haploid induction (HI) genes in sweetpotato. These results provide valuable information for the identification and potential function of HI genes in sweetpotato and provide ideas for the breeding of DH lines. [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]

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

[Objectives]The paper aimed to obtain double haploids of the melon (2n=2x=24) inbred line BPC-4 by distant hybridization, and analyse botanical traits and genomic changes. [Methods]The melon inbred line BPC-4 was used as the maternal parent to cross with eight different materials of the genus Cucumis. F1 generation of the obtained cross was selfed to obtain F2 and F3,which were used for chromosome number observation, SSR molecular marker analysis and plant traits consistency in the same generation to identify their double haploid feature; F2 and F3 were genome resequenced and then purified site distribution and stability of double haploid genome SNP were analyzed. [Results]Among the eight hybrid combinations, three seeds were obtained from the combination of (BPC-4×cucumber inbred line YPJ-6) (2n=2x=14),among which one seed was planted and 50 self-crossing progenies were obtained. The chromosome number of the F2 generation were identified to be 2n=2x=24. SSR identification showed that the PCR bands by 27 SSR markers in F2 generation were the same as those of the maternal parent. The PCR bands of F2 was consistent among single plants and F3 was not separated, indicating that the F2 gene loci were homozygous. Statistical analysis of botanical traits showed that the main changes in F2 were compact and dwarf compared with BPC-4. The average values of internode spacing, stem diameter, leaf length and width, and petiole length in F2 were all lower than those of BPC-4,and F2 individual plants were consistent. The above results proved that the progenies obtained from the distant crosses were double haploid, and thus F1,F2 and F3 were named as DH0,DH1 and DH2,respectively. The data of seed number and seed setting rate of dihaploid showed that fertility of DH0 was low, while fertility of DH1 and DH2 had recovered up to that of BPC-4 and could be used for seed propagation and preserved through self-crossing. The genome resequencing revealed that the double haploid SNP loci were further purified by 0.26% compared with BPC-4,and the new purified loci were distributed on all 12 chromosomes. The difference of purified loci between DH1 and DH2 of the double haploid selfing progeny was 1 016,accounting for only 0.05%,which was smaller than the heterozygosity difference of 3.13% from Mendelian theory conventional self-crossing S4 to S5,indicating that the double haploid genome had been stabilized. [Conclusions]Genome resequencing and botanical trait variation demonstrated that it was still necessary to create a double haploid in melon after four generations of self-crossing, and that the double haploids obtained could be saved by seed for further breeding and theoretical studies.  [ABSTRACT FROM AUTHOR]

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 FROM AUTHOR]

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]

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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.

Maize (Zea mays) hybrid breeding programs are increasingly adopting double haploid (DH) technology to enhance efficiency and meet the growing demand for food in the face of population growth and climate change. However, in developing countries such as those in subtropical regions, the utilization of DH technology is still limited. This study aims to evaluate the potential benefits of incorporating this technology into both new and established maize breeding programs. Using a pedigree selfing population from the CIMMYT Genebank, DH lines were developed and compared to the conventional pedigree selfing method through a line-by-tester evaluation. Fifteen DH lines and fourteen lines from each of the S2, S4, and S6 selfing generations were subjected to multilocation yield trials in the subtropics of Mexico. The results showed that it took three years for the S1 population to identify DH lines with 100 % homozygosity and the highest general combining ability (GCA), which was one year earlier than the S6 lines (98,4 % homozygous). DH lines exhibited more genotype-by-environment interactions (GxE) compared to S2 testcrosses but demonstrated similar heritability to the S6 generation. Significant statistical differences were observed between the DH evaluations and the S4 and S6 testcrosses, while no significant difference was found between the S2 and DH evaluations. Based on these findings, a gradual implementation of DH technology in hybrid breeding programs is recommended. However, the conventional pedigree method should not be abandoned entirely, and testing in selfing generations, particularly in S6, remains crucial. This study provides a statistical comparison of DH versus the conventional pedigree method using a line-by-tester approach, contributing valuable insights for plant breeders and researchers in the field of maize breeding. [ABSTRACT FROM AUTHOR]

Ovule number (ON) produced during flower development determines the maximum number of seeds per silique and thereby affects crop productivity; however, the genetic basis of ON remains poorly understood in oilseed rape (Brassica napus). In this study, we genetically dissected the ON variations in a double haploid (DH) population and in natural population (NP) by linkage mapping and genome-wide association analysis. Phenotypic analysis showed that ON displayed normal distribution in both populations with the broad-sense heritability of 0.861 (DH population) and 0.930 (natural population). Linkage mapping identified 5 QTLs related to ON, including qON-A03, qON-A07, qON-A07-2, qON-A10, and qON-C06. Genome-wide association studies (GWAS) revealed 214, 48, and 40 significant single-nucleotide polymorphisms (SNPs) by individually using the single-locus model GLM and the multiple-locus model MrMLM and FASTMrMLM. The phenotypic variation explained (PVE) by these QTLs and SNPs ranged from 2.00–17.40% to 5.03–7.33%, respectively. Integration of the results from both strategies identified four consensus genomic regions associated with ON from the chromosomes A03, A07, and A10. Our results preliminarily resolved the genetic basis of ON and provides useful molecular markers for plant yield improvement in B. napus. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The DH lines derived from PBW343 × IC252478 were sown for three distinct sowing dates for the years 2017–2018 and 2018–2019. The area chosen for this study was chosen because it is a hot spot for wheat production, and heat stress is a major limitation for wheat growers. In this study, three replicates of the alpha lattice design were employed. Stability measures and genotype–environment interaction were shown to be valuable methods in determining the best lines for heat-stressed environments. Out of 165 DH lines, DH 71, DH 150, DH 34, DH13 DH 64, DH 138, DH 98, DH 84, DH 62, DH 104, DH 74, DH 3, DH 104, DH 107, and DH 156 were ranked closest to ideal and winning genotype in the ranking of genotypes for mean yield, mean versus stability, GGE biplot, and stability performance across the six environments; these were highly adapted, most stable, heat-tolerant, and high-yielding lines. Moreover, the population was also subjected to quantitative trait loci (QTL) mapping for which composite interval mapping (CIM) was performed and it unravelled a total of 36 QTLs where 6 QTLS were detected in non-stressed and 30 QTLs in heat-stressed condition. The detected QTLs spanned on 1A, 1D, 2B, 2D, 3B, 4D, 5B, and 6D chromosomes. The overall goal of the current investigation was to find the best suitable double haploid lines which can withstand heat stress and to find those QTLs which are influential to heat stress for yield-related traits. [ABSTRACT FROM AUTHOR]

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.

Anther culture technique is one of the commonly used method in order to obtain haploid plants in eggplant. It is known that androgenic response in eggplant is variable and one of the most important factors determining success is the genotype effect. Low or insufficient embryogenic response limits the use of doubled haploid technology in breeding programs. Therefore, determining the embryogenic responses of genotypes is a step for the use of this technology in breeding studies. In this study, 61 eggplant genotypes at various breeding stages (F1, F2, and F3) in the gene pool of United Genetics Vegetable Seeds Company (Mustafakemalpaşa, Bursa, Turkey) were evaluated in terms of androgenic responses. Significant differences were determined among eggplant genotypes in terms about embryo induction and conversion rates of embryos to full plantlets. In the study, responsiveness to anther culture based on genotype ranged from 0.0%-21.58%. The conversion rate of induced embryos to plants varied between 0.0% and 100%. [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. [ABSTRACT FROM AUTHOR]

Combination breeding and mutation breeding are widely used methods in plant breeding. Intensive studies are carried out on biotechnological methods that will allow obtaining homozygous lines in a short time in populations obtained with these two techniques. Numerous studies have been carried out by different researchers on mutation breeding in wheat. There are few studies on anther culture response in mutagen-treated genotypes. Two different bread wheat promising advanced lines were used as the material in the study, in which the possibilities of combining mutation breeding with anther culture through ionizing radiation in high quality wheat breeding were investigated. In the study, the responses of advanced bread wheat mutant lines to anther culture, to which eight different doses of gamma rays (0, 100, 150, 200, 250, 300, 350, 400 Gy) were applied, including the control, were investigated. There are significant differences between genotypes and irradiation doses for all traits studied. It has been shown that it is possible to decrease albinism and increase the response of anther culture with dose-dependent gamma irradiation depending on bread wheat varieties. In the multiple comparison test to classify the difference between doses; statistically, 150 gray dose 5.60 is in the first statistical class and in the first place with the number of transferred green plants. After that, it ranks second in the same class with the number of green plants transferred with a 300 gray dose of 5.21. In the total number of regenerated green plants excluding controls (888), 635 unit (71.5%) and 205 unit (23.1%) haploids and spontaneous double haploid plants were obtained, respectively. In the study integrated into the bread wheat breeding program, a total of 205 spontaneous double haploid mutant lines were produced. According to the data obtained, it was shown that the gamma ray doses of 150 and 200 Gy had a significant stimulation effect on all parameters studied and ultimately the success index of anther culture in bread wheat compared to control. [ABSTRACT FROM AUTHOR]

Summary: Reactive oxygen species (ROS) play important roles during anther and pollen development. DNA damage may cause chromosome fragmentation that is considered to underlie chromosome elimination for haploid induction by matrilineal pollen, a key step in MATRILINEAL‐based double haploid breeding technology. But when and how DNA damage occurs is unknown.We performed comparative studies of wheat pollens from the wild‐type and the CRISPR/Cas9 edited matrilineal mutant (mMTL).Chemical assays detected a second wave of ROS in mMTL pollen at the three‐nuclei‐stage and subsequently, along with reduced antioxidant enzyme activities. RNA‐seq analysis revealed disturbed expression of genes for fatty acid biosynthesis and ROS homoeostasis. Gas chromatography‐mass spectrometry measurement identified abnormal fatty acid metabolism that may contribute to defective mMTL pollen walls as observed using electron microscopy, consistent with the function of MTL as a phospholipase. Moreover, DNA damage was identified using TdT‐mediated dUTP nick‐end labelling and quantified using comet assays. Velocity patterns showed that ROS increments preceded that of DNA damage over the course of pollen maturation.Our work hypothesises that mMTL‐triggered later‐stage‐specific ROS causes DNA damage that may contribute to chromosome fragmentation and hence chromosome elimination during haploid induction. These findings may provide more ways to accelerate double haploid‐based plant breeding. [ABSTRACT FROM AUTHOR]

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.