Sugar Beet Breeding Research Articles

Evaluation of the potential for somatic embryogenesis in sugar beet (Beta vulgaris L.) breeding lines and improvement of regeneration efficiency

Evaluation of the potential for somatic embryogenesis in sugar beet (Beta vulgaris L.) breeding lines and improvement of regeneration efficiency

Evaluation of genetic diversity and root traits of sea beet accessions of the Adriatic Sea coast

Thirty-nine sea beet [Beta vulgaris L. ssp. maritima (L.) Arcang.] accessions of the Adriatic coast were screened genetically and for their adaptive morpho-functional root traits in order to identify new sources of abiotic resistances for sugar beet breeding programs. Genetic diversity was evaluated with 21 microsatellites markers that identified 44 polymorphic alleles. Sea beets grouped into two main clusters: the West and the East Adriatic coast groups, with the latter showing higher genetic diversity. Among sea beet accessions with desirable root traits, four accessions have proved to be interesting for sugar beet [B. vulgaris (L.) ssp. vulgaris] breeding aimed to improve tolerance to nutritional stresses. Lastovo (ID 29) and Zut (ID 34) accessions were characterized by the highest values of RER, TRL, FRL and RSA still maintaining a high value of RTD, while Grado (ID 21) an Portic (ID 23) accessions were characterized by the highest RTD, but with low values of RER, TRL, FRL and RSA parameters.

Genome-based prediction of test cross performance in two subsequent breeding cycles

Genome-based prediction of genetic values is expected to overcome shortcomings that limit the application of QTL mapping and marker-assisted selection in plant breeding. Our goal was to study the genome-based prediction of test cross performance with genetic effects that were estimated using genotypes from the preceding breeding cycle. In particular, our objectives were to employ a ridge regression approach that approximates best linear unbiased prediction of genetic effects, compare cross validation with validation using genetic material of the subsequent breeding cycle, and investigate the prospects of genome-based prediction in sugar beet breeding. We focused on the traits sugar content and standard molasses loss (ML) and used a set of 310 sugar beet lines to estimate genetic effects at 384 SNP markers. In cross validation, correlations >0.8 between observed and predicted test cross performance were observed for both traits. However, in validation with 56 lines from the next breeding cycle, a correlation of 0.8 could only be observed for sugar content, for standard ML the correlation reduced to 0.4. We found that ridge regression based on preliminary estimates of the heritability provided a very good approximation of best linear unbiased prediction and was not accompanied with a loss in prediction accuracy. We conclude that prediction accuracy assessed with cross validation within one cycle of a breeding program can not be used as an indicator for the accuracy of predicting lines of the next cycle. Prediction of lines of the next cycle seems promising for traits with high heritabilities.

Molecular genetic investigation of sugar beet (Beta vulgaris L.)

Molecular genetic studies of sugar beet (Beta vulgaris L.) are reviewed as a basis for the development of genomics of this species. The methods used to study structural and functional genomics are considered. The results and their application to increase the efficiency of sugar beet breeding are discussed.

The use of digital image analysis and real‐time PCR fine‐tunes bioassays for quantification of Cercospora leaf spot disease in sugar beet breeding

Cercospora leaf spot, caused by the fungus Cercospora beticola, is a major fungal sugar beet disease worldwide and the cause of significant yield losses. The disease is most successfully countered by the introduction of genetic tolerance into elite sugar beet hybrids. To this end, breeding programmes require high quality biological assays allowing discrimination of minor differences between plants within a segregating population. This study describes the successful implementation of image analysis software in the bioassays for quantification of necrotic lesions at different stages of C. beticola infection, allowing selection on minor phenotypic differences during the sugar beet breeding process for C. beticola resistance. In addition, a real‐time PCR assay was developed for the quantification of C. beticola pathogen biomass in infected beet canopy. The use of both techniques, even in an early stage of infection, fine‐tunes current bioassays, allowing more accurate and efficient selection of resistant breeding material.

Quality Structure of the Noctuidae Family in Selected Habitats of the Agricultural Landscape

Quality Structure of the Noctuidae Family in Selected Habitats of the Agricultural LandscapeThe aim of the study was to compare the Noctuidae moths in three selected farmland environments, using ecological indices. The study was conducted from 2003 to 2006 on fields sown with winter wheat, sugar beets, maize and winter rape plants. The subject of the study was the imago of moth caught by light traps. Light traps (Polish brand) were located at: the Institute of Plant Protection, the Agricultural Research Station in Winna Góra, the Sugar Beet Breeding Research Station in Więcławice and the Institute of Plant Protection in the Poznań research garden. The collected Noctuidae imagines were identified and characterized quantitatively and qualitatively. The Noctuidae imagines were analyzed using Shannon-Weaver's diversity index (H'), Simpson's dominance index (d) and Marczewski-Steinhaus index of similarity (MS %). The results showed a higher similarity between species composition in the agrocenos of Poznań and Więcławice. The smallest diversity of species, reflected in the lowest value of the diversity index and the high value of the dominance index, was observed in the biotic community of Winna Góra which reveals a few Noctuidae, namely:Agrotis segetum(Schiff. et Den.),A. exclamationis(L.),Xestia c-nigrum(L.), andDiscestra trifolii(L.).

Development and application of molecular and bioinformatic tools for the genetic monitoring of wild beets

AbstractCrop Wild Relatives (CWR) are an economically important plant genetic resource (PGR) for plant breeding. One strategy to conserve PGR in the natural habitat (in situ) is the genetic reserve technique. This approach protects the existing intraspecific diversity and allows, in contrast to the ex situ approaches, the emergence of new diversity.The genetic reserve conservation technique will be tested in practice with the Genus Beta within the framework of the EU Project “AEGRO”. Beta patula (Ait.) (BP) and Beta vulgaris (L.) maritima (Arcang.) (BVM) are used as models. Both species are important resources for sugar beet breeding. BP is a rare and endangered species with a very limited habitat. In contrast BVM is widespread along the shores of Western Europe. This subspecies is expected to migrate in a northward direction as a consequence of the global climate change. The impact of this migration on the genetic diversity will be examined in future analyses and will establish a basis for future research.A total of 557 plants from 14 sampling plots were analyzed using 25 SSR markers (Simple Sequence Repeat Marker). Additionally, a monitoring database for storing and post processing all laboratory and field data was developed.For the first time the geographic pattern of genetic diversity in the wild beet BP was described and decision criteria for the establishment of a genetic reserve for BP was postulated. The knowledge of geographic patterns of genetic diversity in the wild beet BVM was consolidated as a baseline for further investigations on the potential influence of climate changes and the corresponding geographic range shift on genetic diversity.

Development and application of molecular and bioinformatic tools for the genetic monitoring of wild beets

Crop Wild Relatives (CWR) are an economically important plant genetic resource (PGR) for plant breeding. One strategy to conserve PGR in the natural habitat (in situ) is the genetic reserve technique. This approach protects the existing intraspecific diversity and allows, in contrast to the ex situ approaches, the emergence of new diversity.The genetic reserve conservation technique will be tested in practice with the Genus Beta within the framework of the EU Project “AEGRO”. Beta patula (Ait.) (BP) and Beta vulgaris (L.) maritima (Arcang.) (BVM) are used as models. Both species are important resources for sugar beet breeding. BP is a rare and endangered species with a very limited habitat. In contrast BVM is widespread along the shores of Western Europe. This subspecies is expected to migrate in a northward direction as a consequence of the global climate change. The impact of this migration on the genetic diversity will be examined in future analyses and will establish a basis for future research.A total of 557 plants from 14 sampling plots were analyzed using 25 SSR markers (Simple Sequence Repeat Marker). Additionally, a monitoring database for storing and post processing all laboratory and field data was developed.For the first time the geographic pattern of genetic diversity in the wild beet BP was described and decision criteria for the establishment of a genetic reserve for BP was postulated. The knowledge of geographic patterns of genetic diversity in the wild beet BVM was consolidated as a baseline for further investigations on the potential influence of climate changes and the corresponding geographic range shift on genetic diversity.

Time course and amplitude of DNA methylation in the shoot apical meristem are critical points for bolting induction in sugar beet and bolting tolerance between genotypes

An epigenetic control of vernalization has been demonstrated in annual plants such as Arabidopsis and cereals, but the situation remains unclear in biennial plants such as sugar beet that has an absolute requirement for vernalization. The role of DNA methylation in flowering induction and the identification of corresponding target loci also need to be clarified. In this context, sugar beet (Beta vulgaris altissima) genotypes differing in bolting tolerance were submitted to various bolting conditions such as different temperatures and/or methylating drugs. DNA hypomethylating treatment was not sufficient to induce bolting while DNA hypermethylation treatment inhibits and delays bolting. Vernalizing and devernalizing temperatures were shown to affect bolting as well as DNA methylation levels in the shoot apical meristem. In addition, a negative correlation was established between bolting and DNA methylation. Genotypes considered as resistant or sensitive to bolting could also be distinguished by their DNA methylation levels. Finally, sugar beet homologues of the Arabidopsis vernalization genes FLC and VIN3 exhibited distinct DNA methylation marks during vernalization independently to the variations of global DNA methylation. These vernalization genes also displayed differences in mRNA accumulation and methylation profiles between genotypes resistant or sensitive to bolting. Taken together, the data suggest that the time course and amplitude of DNA methylation variations are critical points for the induction of sugar beet bolting and represent an epigenetic component of the genotypic bolting tolerance, opening up new perspectives for sugar beet breeding.

Root surface as criterion for selection of sugar beet

In this study we analyzed 10 monogerm and 10 multigerm sugar beet genotypes from the collections of the Institute of Field and Vegetable Crops in Novi Sad. The appearance of sugar beet root surface was evaluated as a property that has an impact on the soil removal and root washing in the sugar factory. The genotypes were tested with nonparametric Kruskal-Wallis's test and cluster analysis as a method of multivariate analysis. Based on these results, genotype 12 had the lowest values for the root surface (the least furrow of the root), which will further be used in sugar beet breeding programs.

Traditional Breeding in Sugar Beet

With rapidly changing agricultural practices, target environments, and biotic and abiotic stresses, plant breeders face the task of continually selecting plants with desirable traits with the goal to assemble advantageous combinations of genes in new varieties. Sugar beet has been selectively bred since the early nineteenth century with the principle objective to develop varieties with the maximum root and sucrose yield potential at the lowest economic and environmental costs possible. Historically, the most productive developments in sugar beet breeding have been monogerm seed, male-sterility and subsequent hybrid development, and pest and disease resistance. Future sugar beet breeding efforts must make use of the genetic and genomic resources available and those under development to improve the productivity and economic stability of sugar beet in global agriculture.

Assisted Breeding in Sugar Beets

Molecular insight and methods applied to plant breeding and germplasm enhancement is the goal of assisted breeding, also known as marker assisted breeding, marker assisted selection, molecular plant breeding, or genome-wide selection, among others. The basic idea is that most, if not all, heritable components of agronomic performance can be assayed with an unbiased, uniform, and comparatively inexpensive set of measures that are highly or completely correlated with phenotypic values. Typically such heritable components are genetically controlled, thus the panoply of DNA-based correlative methods should provide the requisite tools for assisted breeding to be successful. Whether DNA-based methods are successful in predicting agronomic performance depends on a host of considerations, many of which remain to be completely addressed for sugar beet, and thus assisted breeding remains somewhat empirical in practice, at least with respect to the specific traits of interest. Most sugar beet breeding and improvement programs have initiated assisted breeding efforts, primarily as a first step to discover marker associations with traits. These initial activities serve a number of important functions such as determining the complexity of trait inheritance, narrowing the possible range of genes and loci involved in phenotypic expression in different populations, and following the progress of sugar beet improvement following hybridization with wild and unadapted germplasm. It is unlikely that breeding will or should ever rely completely on assisted methods, however selection of the most promising germplasm can be greatly accelerated using molecular insights and knowledge.

テンサイのMarker Assisted Selection(MAS)育種に向けたTaqMan-SNPマーカーの作成(平成22年度年次講演会一般講演)

テンサイのMarker Assisted Selection(MAS)育種に向けたTaqMan-SNPマーカーの作成(平成22年度年次講演会一般講演)

Drought tolerance variability in S1 pollinator lines developed from a sugar beet open population

Drought tolerance is one of the most important objectives of sugar beet breeding programs in semi-arid regions, particularly during the last decade. Due to global climate changes and limitations of agricultural irrigation water, varieties with drought tolerance are taken into consideration in order to avoid yield losses due to drought. In this study, drought tolerance of 76 S1 lines (full-sib families) that had been extracted from a genetically broad base multigerm sugar beet open pollinated population, were examined. Test crosses were made between the lines as pollinators and a cytoplasmic male sterile (CMS) single cross. The consequent hybrids along with checks were evaluated during 2007 and 23 more tolerant hybrids during 2008, in two adjacent experiments under drought stress and non-stress conditions. Drought tolerance indices calculated based on sugar yield, such as mean productivity (MP), geometric mean productivity (GMP) and stress tolerance index (STI) were used to assess hybrids responses to drought. The results showed significant genetic differences for root yield and sugar yield under both conditions. Drought tolerance indices displayed significant genetic variability for sugar yield among the hybrids. Many hybrids were drought tolerant as compared with the original base population as indicated by their high STI. The estimates of heritability for sugar yield in stress and non-stress conditions were much close to each other (0.31 and 0.34, respectively). Whereas, for root yield the heritability estimate in stress condition (0.46) was relatively higher than that in non-stress condition (0.34). Significant differences were observed among the selected hybrids for root yield and sugar yield, indicating genotypic variability for pollinator lines derived from the population. There were no significant differences for sugar content. For increasing the drought tolerance potential in a breeding population and developing drought-tolerant varieties by male parent, the drought-tolerant lines could be used.

SEED PROPERTIES OF THREE PROMISING EGYPTIAN SUGAR BEET GENOTYPES.

Sugar beet breeding program started in Egypt during the last two decades of past century by several Egyptian investigators and breeders, the data was very encouragement. There were three promising multigerm Egyptian sugar beet genotypes (Eg. 6 , Eg. 26 and Eg. 27) have showed good root weight and good sugar percentage at several studied locations. The goal of any sugar beet breeding program is to develop varieties with higher root yield and higher sugar content, better extraction yield (juice purity), higher seed germination percentages, lower tendency to “bolt” and higher resistance to diseases and pests. The objective of this study was to investigate seed properties of the three promising Egyptian sugar beet genotypes (Eg. 6, Eg. 26 and Eg. 27). Seed samples were divided into five fractions according to their size (<3.35, 3.35, 4.0, 5.6 and 6.3 mm). The data cleared that Size 3 = 4.0 mm the most abundant size in all studied samples with average (70.0, 71.1 and 58.5%) in (Eg. 6, Eg. 26 and Eg. 27), respectively. Hundred seed Weight (2.86, 2.90 and 2.54 g), while unit seed Weight values were (0.028, 0.029 and 0.027 g) for (Eg. 6, Eg. 26 and Eg. 27), respectively. Germination percentage, faster germination and seedling vigor were the best in large seed size compared with small seed size.

Research for a sustainable European sugar sector

The paper is based on the results of international project entitled “Towards Sustainable Sugar Industry in Europe (TOSSIE)”. 33 research topics of major importance to the sugar sector are listed and briefly described, and compared with research priorities of the European Technology Platforms: “Food for Life”, “Sustainable Chemistry”, “Biofuels”, and “Plant for the Future”. Most topics are compatible with the research themes included in the COOPERATION part of the 7th Framework Program of the EU (2007-2013). However, some topics may require long-term R&amp;D with the time horizon of up to 15 years. The list of topics is divided into four parts: Sugar manufacturing, Applications of biotechnology and biorefinery processing, Sugarbeet breeding and growing, Horizontal issues. Apart from possible use of the list by policy- and decision makers with an interest in sugarbeet sector, the description of each research topic can be used as a starting point in setting up a research project or other R&amp;D activities.

Apomixis in the Sugar Beet Reproduction System

Research on five lines of sugar beet with a tendency towards apomixis showed the presence of facultative apomicts among the studied plants (2.4%). Facultative agamospermy was detected by isozyme analysis and by nuclear DNA amount estimation using flow cytometry. Genetic segregation according to isozymes in seed progenies showed the presence of meiotic agamospermy; its probable mechanism was normal meiosis in tetraploid cells of the female archespore. The occurrence of cytologically unreduced male gametophytes was confirmed in 21% of the plants by the indirect method of determining ploidy level from the number of pore regions in mature pollen grains. These studies identified homozygotic sublines with a tendency towards apomixis, proposed for practical breeding at the Kutno Sugar Beet Breeding Company Ltd., to be included in breeding experiments as components of heterotic hybrids.

Root traits and yield in sugar beet: identification of AFLP markers associated with root elongation rate

Morpho-physiological and molecular analysis were conducted to identify useful root indexes of sugar beet nutrient uptake capacity and productivity. Root architectural parameters, root elongation rate, sulfate uptake rate and glucose and fructose content in the root apex, traits involved in the plant response to sulfate stress, were evaluated in 18 sugar beet genotypes characterized by different root yield. Morpho-physiological traits, determined on 11-day-old seedlings grown in hydroponics under sulfate deprivation, showed variations from 59 to 197% and were significantly correlated (P < 0.01) with root yield. Under field conditions, the highest root yield genotype (L18), which has the highest root phenotypic values following sulfate shortage, also showed the greatest root length density and leaf relative water content, with respect to the lowest root yield genotype (L01). Bulk segregant analysis based on AFLP analysis, done on a segregating progeny obtained from the cross between the two lines L01 × L18, allowed the identification of two AFLP markers associated to the root elongation rate parameter that showed the highest variation among all the analyzed root traits. The genetic diversity of root adaptive traits and the use of marker-assisted selection aimed at increasing sugar yield under water and nutrient stress in sugar beet breeding programmes are discussed.

Genotypic variation for water use efficiency, carbon isotope discrimination, and potential surrogate measures in sugar beet

Crop water use efficiency (WUE) is increasingly of interest to plant breeders of major crops, including sugar beet ( Beta vulgaris L.), but it is difficult and time-consuming to measure directly. Carbon isotope discrimination (Δ), which can be an indirect, time-integrated measure of WUE in C 3 species, could be used to select for improved WUE in sugar beet if it were shown to be a stable character with high heritability. This study investigated the magnitude of genotype by environment ( G × E) interactions with Δ, and tested the strength of association between WUE, Δ and other traits as potential surrogate measures of WUE. Using sugar beet breeding lines and hybrids with diverse genetic backgrounds, the genotypic variation in WUE, seasonal water use, and total dry matter (TDM) yield were measured under droughted and irrigated conditions in the field in 2004 and 2005. Samples for Δ analysis were taken from mature leaves and from roots at harvest. Results showed that genotypes differed in WUE and sensitivity to water deficit. There was significant genotypic variation for Δ, which was inversely related to WUE. The genotype × treatment × year interaction for TDM was significant but was non-significant for Δ and leaf mass per area (LMA), and some genotypes showed better stability for Δ than others. Leaf ash and chlorophyll content were not related to WUE. In 2005, LMA showed strong negative association with Δ. The results suggest that Δ can be used as an effective selection criterion for improving WUE in sugar beet breeding programmes.

Selection and characterization of resistance to Polymyxa betae, vector of Beet necrotic yellow vein virus, derived from wild sea beet

The plasmodiophoromycete Polymyxa betae is an obligate root parasite that transmits Beet necrotic yellow vein virus (BNYVV), the cause of sugar beet rhizomania disease. Currently, control of this disease is achieved through the use of cultivars with monogenic (Rz1) partial resistance to the virus. To improve the level and durability of this resistance, sources of resistance to the virus vector, P. betae, were sought. Over 100 accessions of the wild sea beet (Beta vulgaris ssp. maritima) from European coastal regions were evaluated for resistance in controlled environment tests. Quantification of P. betae biomass in seedling roots was achieved using recombinant antibodies raised to a glutathione‐s‐transferase expressed by the parasite in vivo. Several putative sources of resistance were identified and selected plants from these were hybridized with a male‐sterile sugar beet breeding line possessing partial virus resistance (Rz1). Evaluation of F1 hybrid populations identified five in which P. betae resistance had been successfully transferred from accessions originating from Mediterranean, Adriatic and Baltic coasts. A resistant individual from one of these populations was backcrossed to the sugar beet parent to produce a BC1 population segregating for P. betae resistance. This population was also tested for resistance to BNYVV. Amplified fragment length polymorphism and single‐nucleotide polymorphism markers were used to map resistance quantitative trait loci (QTL) to linkage groups representing specific chromosomes. QTL for resistance to both P. betae and BNYVV were co‐localized on chromosome IV in the BC1 population, indicating resistance to rhizomania conditioned by vector resistance. This resistance QTL (Pb1) was shown in the F1 population to reduce P. betae levels through interaction with a second QTL (Pb2) found on chromosome IX, a relationship confirmed by general linear model analysis. In the BC1 population, vector‐derived resistance from wild sea beet combined additively with the Rz1 virus resistance gene from sugar beet to reduce BNYVV levels. With partial virus resistance already deployed in a number of high‐yielding sugar beet cultivars, the simple Pb1/Pb2 two‐gene system represents a valuable additional target for plant breeders.