Rapeseed is one of the most important oil crops in the world. Increasing demand for oil and limited agronomic capabilities of present-day rapeseed result in the need for rapid development of new, ...superior cultivars. Double haploid (DH) technology is a fast and convenient approach in plant breeding as well as genetic research.
is considered a model species for DH production based on microspore embryogenesis; however, the molecular mechanisms underlying microspore reprogramming are still vague. It is known that morphological changes are accompanied by gene and protein expression patterns, alongside carbohydrate and lipid metabolism. Novel, more efficient methods for DH rapeseed production have been reported. This review covers new findings and advances in
DH production as well as the latest reports related to agronomically important traits in molecular studies employing the double haploid rapeseed lines.
Brassica napus is an important oil source. Its narrow gene pool can be widened by interspecific hybridization with the Brassicaceae species. One of the agronomically important traits, that can be ...transferred through the hybridization, is the resistance to blackleg, a dangerous disease mainly caused by Leptosphaeria maculans. Hybrid individuals can be analyzed with various molecular markers, including Simple Sequence Repeats (SSR). We investigated the genetic similarity of 32 Brassicaceae hybrids and 19 parental components using SSR markers to reveal their genetic relationship. Furthermore, we compared the field resistance to blackleg of the interspecific progenies. The tested set of 15 SSR markers proved to be useful in revealing the genetic distances in the Brassicaceae hybrids and species. However, genetic similarity of the studied hybrids could not be correlated with the level of field resistance to L. maculans. Moreover, our studies confirmed the usefulness of the Brassicaceae hybrids in terms of blackleg management.
Androgenesis is potentially the most effective technique for doubled haploid production of wheat. It is not however widely used in breeding programmes due to its main limitation: the genotype ...dependence. Due to genetic differences between spring and winter wheat, it was assumed that both phenotypes are different in their capacity to conduct androgenesis. And so, the aim of this investigation was to verify the effectiveness of androgenesis induction and plant regeneration of spring and winter wheat genotypes while considering varying amounts of growth hormones in the induction medium. Fifteen genotypes of spring wheat and fifteen of winter wheat were used in the experiment. Six hundred anthers of each of the 30 genotypes were plated and analysed. Previous studies have allowed selection of the best medium for wheat androgenesis and a combination of growth hormones that are the most effective in stimulating microspore proliferation. Therefore, C17 induction media with two combinations of growth hormones were used: I-supplemented only by auxins (2,4-D and dicamba), and II-supplemented by auxin and cytokinin (2,4-D and kinetin). Data was recorded according to the efficiency of androgenic structure formation (ASF), green plant regeneration (GPR), and albino plant regeneration (APR). The results showed that the induction and regeneration of androgenesis in the spring wheat were more efficient than in the winter ones. The spring genotypes formed more androgenic structures and green plants on anthers plated on the medium supplemented only by auxins, in contrast to the winter genotypes which were better induced and regenerated on the medium supplemented by auxin and cytokinin. The study showed that to increase the efficiency of androgenesis, it is necessary to select appropriate factors such as concentration and type of hormones in medium composition, affecting the course of the culturing procedure according to the winter or spring phenotype of donor plants.
Wild barley is abundant, occupying large diversity of sites, ranging from the northern mesic Mediterranean meadows to the southern xeric deserts in Israel. This is also reflected in its wide ...phenotypic heterogeneity. We investigated the dynamics of DNA content changes in seed tissues in ten wild barley accessions that originated from an environmental gradient in Israel. The flow cytometric measurements were done from the time shortly after pollination up to the dry seeds. We show variation in mitotic cell cycle and endoreduplication dynamics in both diploid seed tissues (represented by seed maternal tissues and embryo) and in the triploid endosperm. We found that wild barley accessions collected at harsher xeric environmental conditions produce higher proportion of endoreduplicated nuclei in endosperm tissues. Also, a comparison of wild and cultivated barley strains revealed a higher endopolyploidy level in the endosperm of wild barley, that is accompanied by temporal changes in the timing of the major developmental phases. In summary, we present a new direction of research focusing on connecting spatiotemporal patterns of endoreduplication in barley seeds and possibly buffering for stress conditions.
Rapeseed (
) can be attacked by a wide range of pests, for example, cabbage root fly (
) and cabbage aphid (
). One of the best methods of pest management is breeding for insect resistance in ...rapeseed. Wild genotypes of
and rapeseed cultivars can be used as a source of resistance. In 2017, 2018, and 2019, field trials were performed to assess the level of resistance to
and
within 53 registered rapeseed cultivars and 31 interspecific hybrid combinations originating from the resources of the Department of Genetics and Plant Breeding of Poznań University of Life Sciences (PULS). The level of resistance varied among genotypes and years. Only one hybrid combination and two
cultivars maintained high level of resistance in all tested years, i.e.,
cv.
×
– PI 649096, Galileus, and Markolo. The results of this research indicate that resistance to insects is present in
family and can be transferred to rapeseed cultivars. The importance of continuous improvement of rapeseed pest resistance and the search for new sources of resistance is discussed; furthermore, plans for future investigations are presented.
Among various methods stimulating biological progress, double haploid (DH) technology, which utilizes the process of microspore embryogenesis (ME), is potentially the most effective. However, the ...process depends on complex interactions between many genetic, physiological and environmental variables, and in many cases, e.g., winter wheat, does not operate with the efficiency required for commercial use. Stress associated with low-temperature treatment, isolation and transfer to in vitro culture has been shown to disturb redox homeostasis and generate relatively high levels of reactive oxygen species (ROS), affecting microspore vitality. The aim of this study was to investigate whether controlled plant growth, specific tiller pre-treatment and culture conditions could improve the potential of microspores to cope with stress and effectively induce ME. To understand the mechanism of the stress response, hydrogen peroxide levels, total activity and the content of the most important low-molecular-weight antioxidants (glutathione and ascorbate), as well as the content of selected macro- (Mg, Ca, NA, K) and micronutrients (Mn, Zn, Fe, Cu, Mo) were determined. These analyses, combined with the cytological characteristics of the microspore suspensions, allowed us to demonstrate that an increased microspore vitality and stronger response to ME induction were associated with higher stress resistance based on more efficient ROS scavenging and nutrient management. It was shown that a modified procedure, combining a low temperature with mannitol and sodium selenate tiller pre-treatment, reduced oxidative stress and improved the effectiveness of ME in winter wheat lines.
Leaf rust caused by the fungus
f. sp.
is one of the most dangerous diseases of common wheat. Infections caused by fungal pathogens reduce the quantity and quality of yields of many cereal species. ...The most effective method to limit plant infection is to use cultivars that show rust resistance. Genetically conditioned horizontal-type resistance (racial-nonspecific) is a desirable trait because it is characterized by more stable expression compared to major (R) genes that induce racially specific resistance, often overcome by pathogens. Horizontal resistance is conditioned by the presence of slow rust genes, which include genes
and
. This study aimed to identify markers linked to both genes in 64 common wheat lines and to develop multiplex PCR reaction conditions that were applied to identify both genes simultaneously. The degree of infestation of the analyzed lines was also assessed in field conditions during the growing season of 2017 and 2018. Simple sequence repeat anchored-polymerase chain reaction (SSR-PCR) marker
was identified during analysis in line PHR 4947. The presence of a specific sequence has also been confirmed in multiplex PCR analyses. In addition to gene
, gene
was identified in this genotype. Lines PHR 4947 and PHR 4819 were characterized by the highest leaf rust resistance in field conditions. During STS-PCR analyses, the marker
of gene
was identified in most of the analyzed lines. This marker was not present in the following genotypes: PHR 4670, PHR 4800, PHR 4859, PHR 4907, PHR 4922, PHR 4949, PHR 4957, PHR 4995, and PHR 4997. The presence of a specific sequence has also been confirmed in multiplex PCR analyses. Genotypes carrying the markers of the analyzed gene showed good resistance to leaf rust in field conditions in both 2017 and 2018. Research has demonstrated that marker assisted selection (MAS) and multiplex PCR techniques are excellent tools for selecting genotypes resistant to leaf rust.
Ionic liquids are novel compounds with unique chemical and physical properties. They can be received based on synthetic auxins like 2,4-dichlorophenoxyacetic acid or dicamba, which are commonly used ...hormones in microspore embryogenesis. Nevertheless, ionic liquids have not been adapted in plant in vitro culture thus far. Therefore, we studied the impact of ionic liquids on the ability to undergo microspore embryogenesis in anther cultures of wheat. Two embryogenic and two recalcitrant genotypes were used for this study. Ten combinations of ionic liquids and 2,4-dichlorophenoxyacetic acid were added to the induction medium. In most cases, they stimulated induction of microspore embryogenesis and green plant regeneration more than a control medium supplemented with only 2,4-dichlorophenoxyacetic acid. Two treatments were the most favorable, resulting in over two times greater efficiency of microspore embryogenesis induction in comparison to the control. The effect of breaking down the genotype recalcitrance (manifested by green plant formation) was observed under the influence of 5 ionic liquids treatments. Summing up, ionic liquids had a positive impact on microspore embryogenesis induction and green plant regeneration, increasing the efficiency of these phenomena in both embryogenic and recalcitrant genotypes. Herbicidal ionic liquids can be successfully used in in vitro cultures.
Cultivated maize (Zea mays L.) is the oldest and one of the most important crop species in the world. Changing climatic conditions in recent years, warm weather, expansion of acreage and ...intensification of maize cultivation have resulted in an increase in the threat posed by diseases caused by, among others, Fusarium fungi. Breeding success in all plant species is determined by access to starting materials with possible high genetic diversity also in terms of disease resistance. Identification of parental combinations that produce offspring that are high-yielding and resistant to Fusarium, among other diseases, is one of the costliest steps in breeding programs. We used maize lines which, as a result of five-year field observations, were divided into resistant and susceptible to F. verticillioides. It is known that resistance to fusarium is a trait strongly dependent on environmental conditions. Due to the fact that the years of observation of the degree of infestation were hot and dry, the resistance of some lines could result from favorable environmental conditions. In view of the above, the aim of this study was to analyze the genetic basis of the resistance of these lines and to correlate molecular analyses with field observations. Comprehensive field and molecular analyses will allow the selection of reference lines that will be resistant to fusarium in the field and, at the same time, will have pyramidized resistance genes. Such lines can be used for crossbreeding to obtain fusarium-resistant varieties. In addition, an attempt was made to develop Multiplex PCR conditions for faster identification of the analyzed markers. As a result of the analyses, it was found that the resistance of the studied maize lines was correlated with the number of molecular markers identified in them. Both field and laboratory analyses have shown that the best line that can be used for crossbreeding as a source of fusarium resistance genes is the line number 25. It has a resistance level of 8–9 on the nine-point COBORU scale. In this line, as a result of molecular analyses, 10 out of 12 markers were identified (SSR 85, Bngl 1063, Bngl 1740, Umc 2082, Bngl 1621, Umc 2059, Umc 2013, SSR 93, SSR 105, STS 03) related to fusarium resistance genes, which may be the reason for such a high resistance to this pathogen. Similarly, 9 markers were identified for line number 35 (SSR 85, Bngl 1063, Bngl 1740, Umc 2082, Bngl 1621, Umc 2059, Umc 2013, SSR 93, STS 03). This line, however, was characterized by a slightly lower resistance at the level of 7–8. Line 254 turned out to be the least resistant, as the resistance was at the level of 4–5, and the number of identified molecular markers was 5. Lines numbered 25 and 35 can be successfully used as a source of fusarium resistance genes.
There are many reports describing chromosome structure, organization and evolution within goatgrasses (
spp.). Chromosome banding and fluorescence
hybridization techniques are main methods used to ...identify
Linnaeus, 1753 chromosomes. These data have essential value considering the close genetic and genomic relationship of goatgrasses with wheat (
Linnaeus, 1753) and triticale (×
Wittmack, 1899). A key question is whether those protocols are useful and effective for tracking
chromosomes or chromosome segments in genetic background of cultivated cereals. This article is a review of scientific reports describing chromosome identification methods, which were applied for development of prebreeding plant material and for transfer of desirable traits into
Linnaeus, 1753 cultivated species. Moreover, this paper is a resume of the most efficient cytomolecular markers, which can be used to follow the introgression of
chromatin during the breeding process.
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