Diagnostic value of Rf1 gene molecular markers in sunflower

Background. Modern production of sunflower seeds is currently based on the cultivation of high-yielding heterotic F1 hybrids from cross-breeding of lines with cytoplasmic male sterility (CMS) of PET1-type and fertility restorer lines. The paternal parent serves as a donor of the nuclear Rf1 gene functional allele, which is responsible for pollen fertility restoration in F1 plants. The detection of carriers of the Rf1 locus recessive and dominant alleles using diagnostic molecular markers accelerates breeding of female and male parental lines for creating hybrids. Materials and methods. The material for the study included 75 lines of various origins from the VIR sunflower genetic collection as well as hybrids from crosses of VIR 116A sterile line with fertile lines differing in the type of cytoplasm (fertile or sterile) and the presence of molecular markers, most of which were linked to the Rf1 locus. For marker validation, two different approaches were used: either by analyzing associations between the ability of a line to restore pollen fertility and the presence of molecular markers in its genotype, or by estimating recombination frequency between the Rf1 locus and marker loci in four segregating hybrid populations. Results. According to the obtained results, no markers demonstrated 100% efficiency in the analysis of the sample of genotypes. The ORS511 marker was most frequently observed among the lines presumably carrying the dominant allele Rf1. Pollen fertility of F1 hybrids from interline crossings was 89-99%. The segregation for fertility/sterility in F2 fitted the theoretical ratio of 3:1 expected in case of the monogenic control of the trait. The markers HRG01, HRG02 and ORS511 were linked to the fertility restoration trait, with recombination rates between Rf1 locus and markers varying in different cross combinations. The analysis of VIR 116А × VIR 740 and VIR 116А × RIL 130 hybrids showed that among the marker loci studied, the ORS511 was closest to the Rf1 locus Rf1 (recombination frequency of 2.2 and 3.3%, respectively). The recombination rate between the Rf1 and ORS511 loci equaled 7.5% in the cross VIR 116А × VIR 210 and 8.9% in VIR 116 × VIR 195. Conclusion. The markers ORS511, HRG01 and HRG02 are the most efficient for the identification of alleles of the Rf1 gene and for the marker assisted selection in hybrid populations produced involving sunflower lines from the VIR collection.

The Effect of Different Pollinators on Fruit Set and Fruit Quality Parameters of Some Foreign Apricot Varieties in Kayseri Ecological Conditions (Central Anatolia, Turkey)

Turkey is among the rare countries in terms of plant diversity, and thus, most plant species spread widely throughout the country. Apricot is one of these plant species. Due to the self-incompatibility seen in apricots, it is necessary to use a pollinator variety for a quality and efficient product. With this study carried out in 2021 year, the effects of different pollinators on fruit set and some fruit quality parameters of Casne Drenova, Ninfa and P. de Tyrinthe cultivars were investigated in Kayseri ecological conditions. In the study, early ripening apricot varieties were used as paternal parent. According to the results of the study, it was shown that fruit set values varied between 11.6% and 22.6%. In the pomological parameters examined in the study, in general (except for fruit firmness), differences were found in combinations using different pollinators compared to the open pollinated fruits of the maternal parent. It is foreseen that the results obtained will be guiding especially in the breeding studies to be carried out with these varieties and in the establishment of new orchards.

de novo variant calling identifies cancer mutation profiles in the 1000 Genomes Project

Detection of de novo variants (DNVs) is critical for studies of disease-related variation and mutation rates. We developed a GPU-based workflow to call DNVs, using 602 trios from the 1000 Genomes Project as a control. We detected 445,711 DNVs, having a bimodal distribution, with peaks at 200 and 2000 DNVs. The excess DNVs are cell line artifacts that are increasing with cell passage. Reduction in DNVs at CpG sites and in percent of DNVs with a paternal parent-of-origin with increasing number of DNVs supports this finding. Detailed assessment of individual NA12878 across multiple genome datasets from 2012 to 2020 reveals increasing number of DNVs over time. Mutation signature analysis across the set revealed individuals had either 1) age-related, 2) B-cell lymphoma, or 3) no prominent signatures. Our approach provides an important advancement for DNV detection and shows cell line artifacts present in lymphoblastoid cell lines are not always random.

Maternal karyogene and cytoplasmic genotype affect the induction efficiency of doubled haploid inducer in Brassica napus

Background Artificial synthesis of octoploid rapeseed double haploid (DH) induction lines Y3380 and Y3560 was made possible by interspecific hybridization and genome doubling techniques. Production of pure lines by DH induction provides a new way to achieve homozygosity earlier in B.napus. Previously, the mechanism of induction, and whether the induction has obvious maternal genotypic differences or not, are not known so far. Results In this study, different karyogene and cytoplasmic genotype of B.napus were pollinated with the previously reported DH inducers e.g. Y3380 and Y3560. Our study presents a fine comparison of different cytoplasmic genotypes hybridization to unravel the mechanism of DH induction. Ploidy identification, fertility and SSR marker analysis of induced F1 generation, revealed that ploidy and phenotype of the induced F1 plants were consistent with that type of maternal, rather than paternal parent. The SNP chip analysis revealed that induction efficiency of DH inducers were affected by the karyogene when the maternal cytoplasmic genotypes were the same. However, DH induction efficiency was also affected by cytoplasmic genotype when the karyogenes were same, and the offspring of the ogura cytoplasm showed high frequency inducer gene hybridization or low-frequency infiltration. Conclusion The induction effect is influenced by the interaction between maternal karyogene and cytoplasmic genotype, and the results from the partial hybridization of progeny chromosomes indicate that the induction process may be attributed to the selective elimination of paternal chromosome. This study provides a basis for exploring the mechanism of DH inducer in B.napus, and provides new insights for utilization of inducers in molecular breeding.

Cross pollination of different peony cultivars with ‘Feng dan’

ABSTRACT: Paeonia ostii ‘Feng dan’ is recommended as a new promising oil crop because of the nutrient elements in its seed; however, the development of this new oil crop is now limited due to its low seed setting rate. This study identified ways to improve the cross pollination of Feng dan as the maternal parent, which has been proved to be a suitable oil crop, so as to improve the seed setting rate of ‘Feng dan’, and to predict the functional relationship between pollen vigor and seed setting rate. improving the efficiency of cross pollination. Three major steps were conducted, first, to screen the appropriate method of measuring pollen vigor of the paternal parent, which could have a strong relationship with seed setting rate. Second, to obtain the corresponding seed setting rate by cross pollination. Third, the functional relationship between two indexes was founded which could be used in cross pollination practice. Results indicated that the best paternal parents of ‘Feng dan’ were ‘Feng dan’ cultivars from other different cultivation populations; The most suitable medium concentration for pollen germination was 100~150 g/L sucrose, 0.06~0.08 g/L boric acid, and 50~200 g/L PEG-6000. Both the seed setting rate and the number of seed grains were positively correlated with the pollen activity, and the seed setting rate was negatively correlated with the local precipitation.

Comprehensive Transcriptomic Analysis for Developing Seeds of a Synthetic Brassica Hexaploid

Polyploidization is a universal phenomenon in plants and plays a crucial role in evolution. In this study, the transcriptomes of developing seeds of a synthetic Brassica hexaploid and its parents (B. rapa and B. carinata) were analyzed to find the gene expression changes in hexaploid seeds. There were 3166 and 3893 DEGs between the Brassica hexaploid and its parents at the full-size stage and mature stage, respectively, most of which were upregulated in hexaploid seeds compared to its parents. At the mature stage, the hexaploid seeds showed a greater difference from its parents. These DEGs had a wide range of functions, which may account for the physiological and morphological differences between the Brassica hexaploid and its parents. The KEGG pathway analysis revealed that hexaploid seeds had higher levels of expression of genes involved in metabolic pathways, RNA transport and biosynthesis of secondary metabolites, and the expression levels in the photosynthesis-related pathways were significantly higher than those in B. rapa. Transgressive expression was the main non-additive expression pattern of the Brassica hexaploid. The gene expression difference between the Brassica hexaploid and its paternal parent was more significant than that with its maternal parent, which may be due in part to the cytoplasmic and maternal effects. Moreover, transcription factor genes, such as G2-like, MYB and mTERF, were highly expressed in hexaploid seeds, possibly promoting their resistance to stress. Our results may provide valuable insights into the adaptation mechanisms of polyploid plants.

Heterosis and genetic diversity in the crossings of gladiolus cultivars Amsterdam and White Prosperity

Gladiolus is one of the most important and popular cut-flower bulbous in Iran. The aim of this research was to produce new, high-quality hybrids through hybridization. We generated two promising hybrids (OPRC16 and OPRC57) combination from the varieties “Amsterdam” and “White Prosperity”. The Research was conducted in Ornamental Plants Research Center in Mahallat from 2014 to 2018. Values of Hm for traits were defined as the difference between the mid-F1 value and the mid-parent value, Mean Mid-parent Heterosis (MPH) or (Hmp) and High Parent Heterosis (HPH) or (Hsp). The results showed that the morphological analysis revealed the heredity and variation in the promising hybrids. The results for the hybrid OPRC16 showed that the Hm and Hmp values were negative for peduncle length but positive for other traits. The Hsp value was observed to be negative for the traits of peduncle length, leaf width, stem diameter, and cormels diameter, but it was positive for other traits. According to the results for the hybrid OPRC57, the Hm and Hmp values were negative for plant height, floret number, peduncle length, floret diameter, stem diameter, spike length, cormles weight, and cormlet diameter and negative for other traits. Peduncle length was positive in other traits. The Hmp value was negative for peduncle length, but positive for other traits. The Hsp value was recorded to be positive for leaf length, bud diameter, vase life, cormlet number, and cormles yield but negative for other traits. All in all, OPRC57 showed a negative heterosis in most traits. Based on the results, when ‘Amsterdam’ is used as the maternal plant in crosses, it has more positive heterosis effects than when it is used as the paternal parent. These results indicate that major of traits in the phenotypic and genetic diversity coefficient was very low, indicating that they had less environmental effects, since the genotypes were cultivated under similar and controlled conditions.

Tetraploid Induction by Colchicine Treatment and Crossing with a Diploid Reveals Less-Seeded Fruit Production in Pointed Gourd (Trichosanthes dioica Roxb.)

Pointed gourd (Trichosanthes dioica Roxb.) (2n = 2x = 22) is a dioecious cucurbit vegetable and green fruit that is edible after cooking. Consumers prefer to consume seedless or less-seeded fruit because seeds are unpalatable due to their hard coats. Therefore, the cross compatibility between the diploid and induced tetraploid will be helpful for seedless or less-seeded fruit production. Thus, the present study was conducted using mature seeds that were immersed in 0.05%, 0.1%, and 0.5% colchicine for 24, 48, and 72 h to induce tetraploids. These tetraploids were used as parents (male or female) in the inter-ploidy and intra-ploidy crosses. A flow cytometric analysis confirmed the induction of three tetraploids at 0.5% colchicine for 48 and 72 h soaking periods. Among these, two (2) females and one (1) male were differentiated after flower initiation. Crossing between the tetraploid’s maternal and diploid paternal parent (4x × 2x), which were revealed to be compatible, resulted in a similar fruit set rate and shape as those of the diploid. In addition, a seed number of 4x × 2x produced fruits that were drastically reduced to 1.8 seeds per fruit, whereas the natural diploid fruits had 26.4 seeds per fruit. These findings suggest that colchicine-induced tetraploid females are important genetic resources for less-seeded fruit production. The genetic stability of tetraploid clones can easily and effectively be maintained by vine cutting for advanced uses.