Showing papers on "Plant breeding published in 2021"

Plant Biotechnology and Transgenic Plants

Abstract: Plant Biotechnology - An Emerging Field. Plant-Derived Drugs and Extracts. Industrial Strategies for the Discovery of Bioactive Compounds from Plants. Plant Cell and Tissue Culture Techniques Used in Plant Breeding. Plant Cell Cultures as Producers of Secondary Compounds. Genetic Transformation of Plants and Their Cells. Properties and Applications of Hairy Root Cultures. Bioreactors for Plant Cell and Tissue Cultures. The Potential Contribution of Plant Biotechnology to Improving Food Quality. Engineering Plant Biochemical Pathways for Improved Nutritional Quality. Transgenic Plants as Producers of Modified Starch and Other Carobhydrates. Improving the Nutritional Quality and Functional Properties of Seed Proteins by Genetic Engineering. Transgenic Plants as Sources of Modified Oils. Flavors and Fragrances from Plants. Fine Chemicals from Plants. Genetic Engineering of the Plant Cell Factory for Secondary Metabolite Production: Indole Alkaloid Production in Catharanthus roseusas a Model. Transgenic Plants for Production of Immunotherapeutic Agents. Signal Transduction Elements. The Plant Cell Wall - Structural Aspects and Biotechnological Developments. Liginin Genetic Engineering: A Way to Better Understand Lignification beyond Applied Objectives. Transgenic Plants Expressing Tolerance Toward Oxidative Stress. Transgenic Plants with Increased Tolerance against Viral Pathogens. Transgenic Plants with Enhanced Tolerance against Microbial Pathogens. Transgenic Crop Plants with Increased Tolerance to Insect Pests. Transgenic Herbicide Resistant Crops - Advantages, Drawbacks and Failsafes. Plants and Environmental Stress Adaptation Strategies. Molecular Mechanisms that Control Plant Tolerance to Heavy Metals and Possible Roles in Manipulating Metal Accumulation. Index.

Wheat, Barley, and Oat Breeding for Health Benefit Components in Grain

Abstract: Cereal grains provide half of the calories consumed by humans. In addition, they contain important compounds beneficial for health. During the last years, a broad spectrum of new cereal grain-derived products for dietary purposes emerged on the global food market. Special breeding programs aimed at cultivars utilizable for these new products have been launched for both the main sources of staple foods (such as rice, wheat, and maize) and other cereal crops (oat, barley, sorghum, millet, etc.). The breeding paradigm has been switched from traditional grain quality indicators (for example, high breadmaking quality and protein content for common wheat or content of protein, lysine, and starch for barley and oat) to more specialized ones (high content of bioactive compounds, vitamins, dietary fibers, and oils, etc.). To enrich cereal grain with functional components while growing plants in contrast to the post-harvesting improvement of staple foods with natural and synthetic additives, the new breeding programs need a source of genes for the improvement of the content of health benefit components in grain. The current review aims to consider current trends and achievements in wheat, barley, and oat breeding for health-benefiting components. The sources of these valuable genes are plant genetic resources deposited in genebanks: landraces, rare crop species, or even wild relatives of cultivated plants. Traditional plant breeding approaches supplemented with marker-assisted selection and genetic editing, as well as high-throughput chemotyping techniques, are exploited to speed up the breeding for the desired genotуpes. Biochemical and genetic bases for the enrichment of the grain of modern cereal crop cultivars with micronutrients, oils, phenolics, and other compounds are discussed, and certain cases of contributions to special health-improving diets are summarized. Correlations between the content of certain bioactive compounds and the resistance to diseases or tolerance to certain abiotic stressors suggest that breeding programs aimed at raising the levels of health-benefiting components in cereal grain might at the same time match the task of developing cultivars adapted to unfavorable environmental conditions.

Target chromosome-segment substitution: A way to breeding by design in rice

Abstract: Progress in plant breeding depends on the development of genetic resources, genetic knowledge, and breeding techniques. The core of plant breeding is the use of naturally occurring variation. At the beginning of the post-genomic era, a new concept of “breeding by design” was proposed, which aims to control all allelic variation for all genes of agronomic importance. In the past two decades, we have applied a three-step strategy for research on rice breeding by design. In the first step, we constructed a single-segment substitution line (SSSL) library using Huajingxian 74 (HJX74), an elite xian (indica) rice cultivar, as the recipient in which to assemble genes from the rice AA genome. In the second step, we identified a series of desirable genes in the SSSL library. In the third step, we designed new rice lines, and achieved the breeding goals by pyramiding target genes in the HJX74-SSSL library. This review introduces the background, concept, and strategy of breeding by design, as well as our achievements in rice breeding by design using the HJX74-SSSL platform. Our practice shows that target chromosome-segment substitution is a way to breeding by design.

The characterization of key physiological traits of medicinal cannabis (Cannabis sativa L.) as a tool for precision breeding

Abstract: For millennia, drug-type cannabis strains were extensively used for various medicinal, ritual, and inebriant applications. However, cannabis prohibition during the last century led to cultivation and breeding activities being conducted under clandestine conditions, while scientific development of the crop ceased. Recently, the potential of medicinal cannabis has been reacknowledged and the now expanding industry requires optimal and scientifically characterized varieties. However, scientific knowledge that can propel this advancement is sorely lacking. To address this issue, the current study aims to provide a better understanding of key physiological and phenological traits that can facilitate the breeding of advanced cultivars. A diverse population of 121 genotypes of high-THC or balanced THC-CBD ratio was cultivated under a controlled environment facility and 13 plant parameters were measured. No physiological association across genotypes attributed to the same vernacular classification was observed. Floral bud dry weight was found to be positively associated with plant height and stem diameter but not with days to maturation. Furthermore, the heritability of both plant height and days to maturation was relatively high, but for plant height it decreased during the vegetative growth phase. To advance breeding efficacy, a prediction equation for forecasting floral bud dry weight was generated, driven by parameters that can be detected during the vegetative growth phase solely. Our findings suggest that selection for taller and fast-growing genotypes is likely to lead to an increase in floral bud productivity. It was also found that the final plant height and stem diameter are determined by 5 independent factors that can be used to maximize productivity through cultivation adjustments. The proposed prediction equation can facilitate the selection of prolific genotypes without the completion of a full cultivation cycle. Future studies that will associate genome-wide variation with plants morphological traits and cannabinoid profile will enable precise and accelerated breeding through genomic selection approaches.

A global barley panel revealing genomic signatures of breeding in modern Australian cultivars

Abstract: The future of plant cultivar improvement lies in the evaluation of genetic resources from currently available germplasm. Today’s gene pool of crop genetic diversity has been shaped during domestication and more recently by breeding. Recent efforts in plant breeding have been aimed at developing new and improved varieties from poorly adapted crops to suit local environments. However, the impact of these breeding efforts is poorly understood. Here, we assess the contributions of both historical and recent breeding efforts to local adaptation and crop improvement in a global barley panel by analysing the distribution of genetic variants with respect to geographic region or historical breeding category. By tracing the impact that breeding had on the genetic diversity of Hordeum vulgare (barley) released in Australia, where the history of barley production is relatively young, we identify 69 candidate regions within 922 genes that were under selection pressure. We also show that modern Australian barley varieties exhibit 12% higher genetic diversity than historical cultivars. Finally, field‐trialling and phenotyping for agriculturally relevant traits across a diverse range of Australian environments suggests that genomic regions under strong breeding selection and their candidate genes are closely associated with key agronomic traits. In conclusion, our combined data set and germplasm collection provide a rich source of genetic diversity that can be applied to understanding and improving environmental adaptation and enhanced yields.

Characterization of Nutritional Quality Traits of a Common Bean Germplasm Collection

Abstract: Food legumes are at the crossroads of many societal challenges that involve agriculture, such as climate change and food sustainability and security. In this context, pulses have a crucial role in the development of plant-based diets, as they represent a very good source of nutritional components and improve soil fertility, such as by nitrogen fixation through symbiosis with rhizobia. The main contribution to promotion of food legumes in agroecosystems will come from plant breeding, which is guaranteed by the availability of well-characterized genetic resources. Here, we analyze seeds of 25 American and European common bean purified accessions (i.e., lines of single seed descent) for different morphological and compositional quality traits. Significant differences among the accessions and superior genotypes for important nutritional traits are identified, with some lines showing extreme values for more than one trait. Heritability estimates indicate the importance of considering the effects of environmental growth conditions on seed compositional traits. They suggest the need for more phenotypic characterization in different environments over different years to better characterize combined effects of environment and genotype on nutritional trait variations. Finally, adaptation following the introduction and spread of common bean in Europe seems to have affected its nutritional profile. This finding further suggests the relevance of evolutionary studies to guide breeders in the choice of plant genetic resources.

Overexpression of GhMPK3 from Cotton Enhances Cold, Drought, and Salt Stress in Arabidopsis

Abstract: Cotton production is hampered by a variety of abiotic stresses that wreak havoc on the growth and development of plants, resulting in significant financial losses. According to reports, cotton production areas have declined around the world as a result of the ongoing stress. Therefore, plant breeding programs are concentrating on abiotic stress-tolerant cotton varieties. Mitogen-activated protein kinase (MAPK) cascades are involved in plant growth, stress responses, and the hormonal signaling pathway. In this research, three abiotic stresses (cold, drought, and salt) were analyzed on GhMPK3 transformed Arabidopsis plants. The transgenic plant’s gene expression and morphologic analysis were studied under cold, drought, and salt stress. Physiological parameters such as relative leaf water content, excised leaf water loss, chlorophyll content, and ion leakage showed that overexpressed plants possess more stable content under stress conditions compared with the WT plants. Furthermore, GhMPK3 overexpressed plants had greater antioxidant activities and weaker oxidant activities. Silencing GhMPK3 in cotton inhibited its tolerance to drought stress. Our research findings strongly suggest that GhMPK3 can be regarded as an essential gene for abiotic stress tolerance in cotton plants.

Breeding Aspects of Selected Ornamental Bulbous Crops

Abstract: This article provides an overview of the origin, genetic diversity and methods and trends in breeding of selected ornamental geophytes (Lilium, Tulipa, Narcissus and Hippeastrum). The role of interspecific hybridisation and polyploidisation in assortment development is reviewed. A great variety of cultivars with traits of interest have been generated over the last century by using classical breeding. Geophyte breeders have been interested in a diversity of traits, including resistance to diseases, flower colour and shape, long lasting flowering and a long vase life. Shortening the long breeding process of many geophytes by reducing the juvenile phase and using in vitro techniques are reviewed. Currently, the breeding process has been enhanced by using modern molecular cytogenetic techniques. Genomic in situ hybridisation is frequently used, among other techniques, for genome differentiation in interspecific hybrids, and for assessment of the extent of intergenomic recombination in backcross progenies. Furthermore, several molecular marker techniques are used for verification of hybrid status, identification of genetic diversity, confirmation of the genetic fidelity of in vitro propagated plants and construction of high-density linkage maps. Recently, a myriad of new plant breeding technologies, such as cisgenetics and genome editing technologies have been used to improve the traits of ornamental geophytes, an endeavour that is discussed here. Breeding trends, cultivar novelties as well a new cultivars registered by international authorities during the last five years are presented in detail.

Genetic diversity and population structure of groundnut (Arachis hypogaea L.) accessions using phenotypic traits and SSR markers: implications for rust resistance breeding

Abstract: Groundnut (Arachis hypogaea L.) is a multi-purpose legume serving millions of farmers and their value chain actors globally. Use of old poor-performing cultivars contributes to low yields (< 1 t/ha) of groundnut in sub-Saharan Africa including Tanzania. The objectives of this study were to determine the extent of genetic variation among diverse groundnut collections using phenotypic traits and simple sequence repeat (SSR) markers to select distinct and complementary genotypes for breeding. One hundred and nineteen genotypes were evaluated under field conditions for agronomic traits and susceptibility to rust and leaf spot diseases. The study was conducted in two locations across two seasons. In addition, the 119 accessions were profiled with 13 selected SSR markers. Genotype and genotype by environment interaction effects were significant (p < 0.05) for days to flowering (DTF), late leaf spot score at 85 and 100 days after planting, pod yield (PDY), kernel yield (KY), hundred seed weight (HSW) and shelling percentage (SP). Principal components analysis revealed that plant stand, KY, SP, NPP (number of pods per plant), late leaf spot and rust disease scores accounted for the largest proportion of the total variation (71.9%) among the tested genotypes. Genotypes ICGV-SM 08587 and ICGV-SM 16579 had the most stable yields across the test environments. Moderate genetic variation was recorded with mean polymorphic information content of 0.34 and gene diversity of 0.63 using the SSR markers. The majority (74%) of genotypes showed high membership coefficients to their respective sub-populations, while 26% were admixtures after structure analysis. Much of the variation (69%) was found within populations due to genotypic differences. The present study identified genotypes ICGV-SM 06737, ICGV-SM 16575, ICG 12725 and ICGV-SM 16608 to be used for development of mapping population, which will be useful for groundnut improvement. This study provided a baseline information on characterization and selection of a large sample of groundnut genotypes in Tanzania for effective breeding and systematic conservation.

Response of rice (Oryza sativa L.) cultivars to elevated ozone stress

Abstract: The plant response to elevated ozone stress reveals inter-species and intra-species disparity. Ozone-induced crop yield loss is predicted to increase in the future, posing a threat to the world economy. This study aims to evaluate the cultivar specific variation in rice exposed to elevated ozone. Fifteen short-duration rice cultivars were exposed to 50 ppb ozone for 30 days at reproductive stage. The physiological, biochemical, growth and yield traits of all test cultivars were significantly affected in response to elevated ozone. On an average, ozone stress decreased the tiller number by 22.52%, number of effective tillers by 30.43%, 1000 grain weight by 0.62% and straw weight by 23.83% over control. Spikelet sterility increased by 19.26% and linear multiregression 3D model significantly fits the spikelet sterility and photosynthetic traits with the R2 of 0.74 under elevated ozone. Principal Component Analysis with total variance of 57.5% categorized 15 rice cultivars into four major groups, i.e., ozone sensitive (MDU6, TRY(R)2 and ASD16), moderately ozone sensitive (ASD18, ADT43, and MDU5), moderately ozone tolerant (ADT37, ADT(R)45, TPS5, Anna(R)4, PMK(R)3, and ADT(R)48), and ozone tolerant (CO51, CO47, and ADT36). This study indicates that the different responses of rice cultivars to elevated ozone stress through a change in plant physiology, biochemical, growth, and yield traits and the results directed to provide scientific information on plant adaptations to ozone stress and helps in efforts to search ozone tolerant gene for plant breeding.

Root and canopy traits and adaptability genes explain drought tolerance responses in winter wheat.

Abstract: Bread wheat (Triticum aestivum L) is one of the three main staple crops worldwide contributing 20% calories in the human diet. Drought stress is the main factor limiting yields and threatening food security, with climate change resulting in more frequent and intense drought. Developing drought-tolerant wheat cultivars is a promising way forward. The use of holistic approaches that include high-throughput phenotyping and genetic markers in selection could help in accelerating genetic gains. Fifty advanced breeding lines were selected from the CIMMYT Turkey winter wheat breeding program and studied under irrigated and semiarid conditions in two years. High-throughput phenotyping was done for wheat crown root traits and canopy senescence dynamics using vegetation indices (green area using RGB images and Normalized Difference Vegetation Index using spectral reflectance). In addition, genotyping by KASP markers for adaptability genes was done. Overall, under semiarid conditions yield reduced by 3.09 t ha-1 (-46.8%) compared to irrigated conditions. Genotypes responded differently under drought stress and genotypes 39 (VORONA/HD24-12//GUN/7/VEE#8//…/8/ALTAY), 18 (BiII98) and 29 (NIKIFOR//KROSHKA) were the most drought tolerant. Root traits including shallow nodal root angle under irrigated conditions and root number per shoot under semiarid conditions were correlated with increased grain yield. RGB based vegetation index measuring canopy green area at anthesis was better correlated with GY than NDVI was with GY under drought. The markers for five established functional genes (PRR73.A1 -flowering time, TEF-7A -grain size and weight, TaCwi.4A - yield under drought, Dreb1- drought tolerance, and ISBW11.GY.QTL.CANDIDATE- grain yield) were associated with different drought-tolerance traits in this experiment. We conclude that-genotypes 39, 18 and 29 could be used for drought tolerance breeding. The trait combinations of canopy green area at anthesis, and root number per shoot along with key drought adaptability makers (TaCwi.4A and Dreb1) could be used in screening drought tolerance wheat breeding lines.

The genetic structure of CIMMYT and U.S. inbreds and its implications for tropical maize breeding

Abstract: Assigned to Associate Editor Timothy Beissinger. Abstract The use of temperate maize (Zea mays L.) inbreds with expired Plant Variety Protection in tropical maize breeding programs could enhance the combining ability for grain yield among tropical heterotic groups. We used DNA markers from the DArTseq genotyping-by-sequencing platform to investigate the genetic structure of lines with expired U.S. Plant Variety Protection (ex-PVP) relative to the International Maize and Wheat Improvement Center’s (CIMMYT’s) maize heterotic groups. Neighbor-joining cluster analysis revealed two major groups: CIMMYT and ex-PVP. The CIMMYT lines clustered according to their pedigree relationships and adaptation, but not according to their heterotic groups. In contrast, ex-PVP lines clustered according to the Stiff Stalk Synthetic (BSSS) and non-Stiff Stalk Synthetic (NSSS) heterotic groups, except for a few lines that were considered to be mixed. The genetic divergence, estimated as Wright’s fixation index (FST), between BSSS and NSSS (FST = .053, P < .01) was four times as large as the divergence between CIMMYT Tuxpeño and non-Tuxpeño heterotic groups (FST = .013, P = .068). Estimates of genetic divergence marginally favored breeding with BSSS in Tuxpeño and NSSS in non-Tuxpeño. However, CIMMYT breeders may still exploit the ex-PVP heterotic structure fully only by ensuring that the temperate heterotic groups are placed on opposite sides of the Tuxpeño and non-Tuxpeño heterotic pattern. We also showed how estimates of admixture from model-based clustering could be used to avoid ex-PVP lines of mixed heterotic background when selecting lines to maximize the genetic divergence and combining ability of CIMMYT heterotic groups.

Genomic Selection for Wheat Improvement

Abstract: Recent advances in plant breeding and agronomic practices have contributed significantly to the annual genetic gain in crop productivity to the tune of 0.8–1.2%. However, the present rate of gain is insufficient to meet out the fast-growing food demand of the expected global population of 2050. Till 1980s genetic enhancement of crop plants was primarily based on conventional plant breeding approaches. Although conventional breeding is continued to be breeder’s choice, faster genetic gain is hampered particularly for complex traits. Increasing the rate of genetic gain through modern breeding technologies is essential for food and nutritional security. Genomic selection (GS) is one such proven technology in animal breeding and recently incorporated in plant breeding programmes, especially large-scale private sector. GS is a promising approach for the rapid selection of superior genotypes and accelerating the breeding cycle. A comprehensive review of the existing GS literature in crop plants may provide insights for integrating GS in crop breeding programmes. Incorporation and effective use of GS in breeding programme depend upon several factors such as breeding method, genetic architecture and heritability number of targeted traits, statistical models, availability of genotyping and phenotyping facilities and the budget of breeding program. In this chapter, we discuss GS in wheat while highlighting various studies carried for improvement of grain yield, biotic and abiotic stresses, disease resistance and grain quality parameters. Also discussed are the challenges and key considerations to be followed for successful implementation of GS in varietal development programmes. Most of the GS studies are used to predict the additive genetic value and lag behind for non-additive and Genotype X Environment Interaction (GEI). Multi-trait and multi-environment modelling is essential for improving the prediction accuracy for environment-sensitive traits. Another potential of GS is mining of genes in gene bank accessions to access unexplored diversity into breeding programmes.

Drought Tolerance in Some Field Crops: State of the Art Review

Abstract: Drought stress has a significant negative impact on plant growth, yield and quality of crop plants, particularly under current climate change Therefore, improving drought tolerance in field crops is essential to increase sustains productivity particularly in arid and semi-arid regions in the Mediterranean basin There are various selection criteria associated with drought tolerance could be exploited in selecting drought-tolerant genotypes Combining morpho-physiological and biochemical traits can provide a more completed model of gene-to-phenotype relationships and genotype-by-environment interactions Integration of recent advances breeding methods as quantitative trait loci, marker-assisted selection and genetic engineering technique with classic plant breeding helps significantly in developing drought-tolerant genotypes accurately and rapidly This chapter also addresses to genetic diversity among genotypes, related traits to drought tolerance, genetic behavior, breeding efforts and biotechnology in rice, maize, barley and sunflower

Application Techniques of Molecular Marker and Achievement of Marker Assisted Selection (MAS) in Three Major Crops Rice, Wheat and Maize

Abstract: With the discovery of new genetic technology, the researcher focuses on using DNA molecular markers to improve new varieties worldwide. Such as resistance to biotic and abiotic stresses and enhancing quality and quantity at different plant breeding fields. Conventional breeding selection is based on phenotype data selection, time-consuming, and has a high chance of linkage drag. Thus, DNA molecular marker method usage is faster, easy, and not expensive than conventional breeding programs. This review focused on applying molecular markers such as genetic diversity analysis, the genotype of identification and fingerprinting, gene tagging and mapping, QTL analysis, and marker-assisted selection. In another part of this review, we focused on MAS's achievements related to improving agronomic traits, quality traits, and biotic/abiotic stresses for three major cereal crops like Wheat, Rice, and Maize.

Agronomic characters, genetic and phenotypic diversity coefficients, and heritability of 12 genotypes of rice

Abstract: Kartahadimaja J, Utomo SD, Yuliadi E, Salam AK, Warsono, Wahyudi A. 2021. Agronomic characters, genetic and phenotypic diversity coefficients, and heritability of 12 genotypes of rice. Biodiversitas 22: 1091-1097. The achievement of national rice production is always below the target. One of the causes is the low productivity of the varieties grown due to the stagnant g enetic capacity of these varieties. The assembly of new lines through breeding is one solution that can increase the genetic capacity of new varieties. Genetic diversity is one of the factors that influence the success of plant breeding. Ten new F9 rice lines were s uccessfully assembled showing various phenotypes. The identification of the specific advantages of each of these new rice lines was based largely on the phenotypic response. The research objective was to identify the genetic advantages of each line through the analysis a pproach of genetic diversity coefficient (GDC), Phenotific Diversity Coefficient (PDC), and broad-sense heritability. The research was designed on a randomized completely block design (RCBD) with ten new F9 rice lines and two comparison varieties as treatments, repeated three times. The variables observed were plant height, maximum number of tillers, number of productive tillers, flowering time, harvesting time, panicle length, number of grain per panicle, number of filled grains per panicle, number of empty grain p er panicle, grain length, grain width, grain thickness, and grain yield per hectare. The data were analyzed using Analysis of Variance (ANOVA), if there was a difference between the mean values, it was continued with a 5% LSD test. The results showed that (i) the genotypes tested showed wide genetic and phenotypic diversity, (ii) based on the analysis of GDC, PDC, and broad sense heritability, the appearance of phenotypes of several agronomic characters was controlled by genetic factors. Keywords: Agronomic characters, genetic diversity, heritability, phenotypic diversity, rice production Abbreviations: GDC: diversity coefficient; PDC: phenotypic diversity coefficient

Recent molecular and breeding strategies in lettuce (Lactuca spp.)

Abstract: Lettuce (Lactuca spp.) is an annual and self-pollinating crop that belongs to the Asteraceae (Compositae) family. It is one of the most globally essential commercial vegetable crops, used in salads and sandwiches. The lettuce leaves are used to make a cigarette without nicotine. Seeds and stems contain edible oil and dried latex. Gene banks have conserved a large pool of lettuce's genetic resources, including wild Lactuca species with the same chromosome numbers 2n = 2x = 18. Lactuca species vary greatly in terms of geographical distribution and morpho-agronomic characteristics. By crossing commercial varieties with locally adapted varieties, novel alleles can be introduced, increasing genetic diversity and making preselection for desirable traits easier. Lettuce breeders and geneticists' main objectives are to improve lettuce for various desirable traits, including tolerance to abiotic and biotic stress and high yield. These targets accomplished with modern genomics tools together with traditional breeding methods. This chapter discusses lettuce conservation and biodiversity, stages of lettuce breeding, agriculture practices, and conventional breeding techniques and their restrictions. It also includes modern plant breeding tools and marker-assisted breeding, editing of genome, and genetic engineering.

Long-term breeding progress of yield, yield-related, and disease resistance traits in five cereal crops of German variety trials.

Abstract: KEY MESSAGE Considerable breeding progress in cereal and disease resistances, but not in stem stability was found. Ageing effects decreased yield and increased disease susceptibility indicating that new varieties are constantly needed. Plant breeding and improved crop management generated considerable progress in cereal performance over the last decades. Climate change, as well as the political and social demand for more environmentally friendly production, require ongoing breeding progress. This study quantified long-term trends for breeding progress and ageing effects of yield, yield-related traits, and disease resistance traits from German variety trials for five cereal crops with a broad spectrum of genotypes. The varieties were grown over a wide range of environmental conditions during 1988-2019 under two intensity levels, without (I1) and with (I2) fungicides and growth regulators. Breeding progress regarding yield increase was the highest in winter barley followed by winter rye hybrid and the lowest in winter rye population varieties. Yield gaps between I2 and I1 widened for barleys, while they shrank for the other crops. A notable decrease in stem stability became apparent in I1 in most crops, while for diseases generally a decrasing susceptibility was found, especially for mildew, brown rust, scald, and dwarf leaf rust. The reduction in disease susceptibility in I2 (treated) was considerably higher than in I1. Our results revealed that yield performance and disease resistance of varieties were subject to considerable ageing effects, reducing yield and increasing disease susceptibility. Nevertheless, we quantified notable achievements in breeding progress for most disease resistances. This study indicated an urgent and continues need for new improved varieties, not only to combat ageing effects and generate higher yield potential, but also to offset future reduction in plant protection intensity.

DArT-based evaluation of soybean germplasm from Polish Gene Bank.

Abstract: Soybean is an important plant used for food, feed and many industrial purposes. Interest in soybean breeding is growing in Central Europe, including Poland. A very large number of soybean accessions are stored in gene banks, but less than 1% of them have been used for breeding. Here, we present genotypic data as well as phenotypic data on plant and seed performance, including seed chlorophyll fluorescence traits, and on yield components within a collection of soybean accessions that are conserved in the Polish Gene Bank at the Plant Breeding and Acclimatization Institute-National Research Institute. The materials used consisted of sub-collections: 79 Polish genotypes, including old traditional cultivars, 24 Canadian, 21 American, 21 Swedish and 31 from Central and Eastern European Countries, 9 from France and 6 from Japan. In total, 9602 high quality SNPs were derived from DArTseq, a method utilising GBS technology. GWAS, performed with the BLINK model, revealed that a total of 41 significant SNPs were mapped for days to flowering, flower colour, plant height, days to pod formation, 100 seed weight, pod colour, seeds and hilum colour and steady-state chlorophyll fluorescence under light (Ft_Lss). This is the first report about the diversity of traditional old Polish soybean cultivars.

Innovative technologies in agricultural crops breeding and seed farming

Abstract: Plant breeding involves the study of ways of creation of the new varieties of cultivated plants with important traits and improvement of the existing one. The following basic breeding methods are distinguished: selection, hybridization, mutagenesis and polyploidy. In 2019, the share of domestic breeding seeds in the total volume of seeds was 62.7%, for sugar beets - 0.6, sunflower - 26.5, vegetables - 43, corn - 45.8, soybeans - 41.8%. For winter and spring wheat, this indicator was 90.5 and 82.2%, respectively. The food security doctrine for seeds as a whole sets the indicator at no less than 75%. Import dependence on seeds and hybrids of agricultural crops is due to a number of factors: low competitive potential of newly registered varieties and hybrids, low quality of seeds, deficiencies in the system for stimulation of variety renewal, underdeveloped infrastructure, outdated material and technical base, lack of highly qualified specialists in genetics, breeding and seed production.

Evaluation of salt tolerance in maize (Zea mays L.) at seedling stage through morphological characters and salt tolerance index

Abstract: Abiotic stressors such as salinity cause major yield losses in maize (Zea mays). To reduce the impact of salinity and breed for salt tolerance, precise phenotypic screening of maize genotypes at seedling stage is imperative. A laboratory experiment was conducted in the Department of Genetics and Plant Breeding, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh during rabi season (November–March) of 2017–18. Twenty maize inbred lines were assessed for salt tolerance at both germination and the seedling stage. The experiment was conducted using a completely randomized block design with three replications and four treatments viz. T0 (0 dS m−1), T1 (5 dS m−1), T2 (10 dS m−1) and T3 (15 dS m−1). The analysis of variance revealed highly significant (p < 0.001) differences in genotypes, treatments and interaction of genotype × treatment for most of the germination, shoot and root traits except root shoot ratio (fresh). Overall, the germination and shoot trait performances were more affected for most of the genotypes viz. ML13, ML25, ML03 with increasing the salinity level while less affected for root traits. The superior performances under control conditions (T0) was revealed by ML05 and under salt stress conditions (T1, T2, T3), the genotype ML28. Most of the shoot and root traits revealed stronger and significant correlations with each other except root shoot ratio for fresh and dry weights. The results of salt tolerance index (STI) indicated the superiority of genotype ML28 followed by the genotypes ML05, ML10, ML26, and ML19. These genotypes should be considered for further salt tolerance breeding in maize.

Genetic factors controlling nTiO2 nanoparticles stress tolerance in barley (Hordeum vulgare) during seed germination and seedling development.

Abstract: Titanium dioxide nanoparticle (nTiO2) is one of the most produced nanoparticles worldwide. Its mechanism on crop development and performance is unclear as it is hard to predict their toxicity or benefit. Therefore, understanding the genetics of crop development under nTiO2 is a prerequisite for their applications in agriculture and crop improvement. Here, we aimed to examine the influnce of 300ppm nTiO2 on seed germination, seedling morphology, root-related traits in 121 worldwide spring barley (Hordeum vulgare L.) accessions. Results show that nTiO2 significantley affected all traits scored in this study. Response to nTiO2 treatment, clear wide natural variation among accesions was detected. Remarkably, 10 genotypes showed increased root length under nTiO2 at the seedling stage indicating that nTiO2 enhanced the root elongation. Genome-wide association scan (GWAS) was applied using 9K single nucleotide polymorphism (SNPs) in a mixed-linear model that revealed 86 significant marker-trait associations with all traits scored in this study. Many significant SNPs were physically located near candidate genes, of which 191 genes were detected within the linkage disequilibrium and distributed over all barley chromosomes. Mostly, the genes harboured by chromosome 2H, specially calcium-binding genes family, regulate the variation of seedling length-related traits. Candidate genes on 7H encode zinc finger protein that controls the rate of germination. Therefore, these genomic regions at 2H and 7H can be targeted to select for improved seedling development and seed germination under nTiO2 stress in soils. These results improve understanding the genetic control of seed germination and seedling development under high levels of nTiO2 that can support plant breeding and crop improvement programmes.

Induction of Male Sterility: A Boon for Plant Breeding

Abstract: In general, the life cycle of plants consists of two phases, one prolonged vegetative or sporophytic generation and a short sexual or gametophytic generation. During the entire period a seed germinate, differentiate into root and shoot, undergoes vegetative growth and completes its life cycle once the flower is converted into fruit. Male sterility is a common phenomenon seen in higher plant species. Inability of a living organism for sexual reproduction is known as sterility and failure to produce functional pollen is called male sterility. In agriculture, male sterility has been proven as highly beneficial to produce hybrid seeds which are often superior in terms of quality and yield compared to their parents. Plants exhibits diverse forms of male sterility, like absence of normal anthers or reduced anther size, difference in petaloidy, abnormal meiosis which leads to formation of empty, shriveled microspores or normal meiosis, but with abnormal microspore development and failure of anthesis that doesn‟t allow pollen shed (Kaul, 1988). In all the above cases of International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 10 Number 02 (2021) Journal homepage: http://www.ijcmas.com

Molecular Breeding Strategies of Beetroot (Beta vulgaris ssp. vulgaris var. conditiva Alefeld)

Abstract: Beetroot, table beet, red beet or garden beet (Beta vulgaris ssp. vulgaris var. conditiva Alefeld) is a cross-pollinated crop that belongs to the family Chenopodiaceae. It is one of the most essential and economical cultivated vegetables. Globally, beetroot is used for food products, pickles, salads and juice rather than for sugar production. Also, edible sugar can be extracted from the root. Gene banks have conserved a wide variety of genetic resources from beetroot including wild species. There are several species with various chromosome numbers. Beta harbors significant diversity based on geographic regions and morphological features. Introgression of novel alleles by crossing different genetic resources for the beetroot e.g. crossing common varieties with locally developed varieties increases genetic diversity and pre-selects for useful traits. It is necessary to ensure ample natural variation in phenotypes. The key goals of breeders and geneticists are to improve beetroot for different desirable traits including tolerance to biotic and abiotic stress, quality and yield characteristics. Applying modern genetic tools to improve conventional breeding programs can further the achievement of these goals. This chapter provides an overview and limitations of the beetroot germplasm biodiversity and conservation, objectives and stages of beetroot breeding programs and conventional breeding methods. Additionally, it addresses modern methods of plant breeding, including marker-assisted breeding and genetic engineering.