Evaluation of barley testing locations in Ontario

In order to develop new barley cultivars, promising genotypes are evaluated for their performance each year at a number of test locations representing the target region. In this study, we analyzed the Ontario barley registration trial data from 2015 to 2020 to understand the barley mega-environment in Ontario and to evaluate the suitability of the test locations. The analysis showed that the barley test locations fall into two mega-environments, with a major mega-environment consists of five test locations and a minor mega-environment with a single test location. Among the six test locations used for the barley registration trials, Palmerston was found to be the most desirable for the barley cultivar evaluation representing the Ontario barley growing region. This study also identified OB2930-35, a recently released cultivar, to be both high yielding and stable across Ontario. These findings are useful for future barley breeding and cultivar evaluation in Ontario.

Genome-Wide Association Study of Waterlogging Tolerance in Barley (Hordeum vulgare L.) Under Controlled Field Conditions

Waterlogging is one of the main abiotic stresses severely reducing barley grain yield. Barley breeding programs focusing on waterlogging tolerance require an understanding of genetic loci and alleles in the current germplasm. In this study, 247 worldwide spring barley genotypes grown under controlled field conditions were genotyped with 35,926 SNPs with minor allele frequency (MAF) > 0.05. Significant phenotypic variation in each trait, including biomass, spikes per plant, grains per plant, kernel weight per plant, plant height and chlorophyll content, was observed. A genome-wide association study (GWAS) based on linkage disequilibrium (LD) for waterlogging tolerance was conducted. Population structure analysis divided the population into three subgroups. A mixed linkage model using both population structure and kinship matrix (Q+K) was performed. We identified 17 genomic regions containing 51 significant waterlogging-tolerance-associated markers for waterlogging tolerance response, accounting for 5.8–11.5% of the phenotypic variation, with a majority of them localized on chromosomes 1H, 2H, 4H, and 5H. Six novel QTL were identified and eight potential candidate genes mediating responses to abiotic stresses were located at QTL associated with waterlogging tolerance. To our awareness, this is the first GWAS for waterlogging tolerance in a worldwide barley collection under controlled field conditions. The marker-trait associations could be used in the marker-assisted selection of waterlogging tolerance and will facilitate barley breeding.

The Breeding of Winter-Hardy Malting Barley

In breeding winter malting barley, one recurring strategy is to cross a current preferred spring malting barley to a winter barley. This is because spring malting barleys have the greatest amalgamation of trait qualities desirable for malting and brewing. Spring barley breeding programs can also cycle their material through numerous generations each year—some managing even six—which greatly accelerates combining desirable alleles to generate new lines. In a winter barley breeding program, a single generation per year is the limit when the field environment is used and about two generations per year if vernalization and greenhouse facilities are used. However, crossing the current favored spring malting barley to a winter barley may have its downsides, as winter-hardiness too may be an amalgamation of desirable alleles assembled together that confers the capacity for prolonged cold temperature conditions. In this review I touch on some general criteria that give a variety the distinction of being a malting barley and some of the general trends made in the breeding of spring malting barleys. But the main objective of this review is to pull together different aspects of what we know about winter-hardiness from the seemingly most essential aspect, which is survival in the field, to molecular genetics and gene regulation, and then finish with ideas that might help further our insight for predictability purposes.

Evaluation of RGB and Multispectral Unmanned Aerial Vehicle (UAV) Imagery for High-Throughput Phenotyping and Yield Prediction in Barley Breeding

With advances in plant genomics, plant phenotyping has become a new bottleneck in plant breeding and the need for reliable high-throughput plant phenotyping techniques has emerged. In the face of future climatic challenges, it does not seem appropriate to continue to solely select for grain yield and a few agronomically important traits. Therefore, new sensor-based high-throughput phenotyping has been increasingly used in plant breeding research, with the potential to provide non-destructive, objective and continuous plant characterization that reveals the formation of the final grain yield and provides insights into the physiology of the plant during the growth phase. In this context, we present the comparison of two sensor systems, Red-Green-Blue (RGB) and multispectral cameras, attached to unmanned aerial vehicles (UAV), and investigate their suitability for yield prediction using different modelling approaches in a segregating barley introgression population at three environments with weekly data collection during the entire vegetation period. In addition to vegetation indices, morphological traits such as canopy height, vegetation cover and growth dynamics traits were used for yield prediction. Repeatability analyses and genotype association studies of sensor-based traits were compared with reference values from ground-based phenotyping to test the use of conventional and new traits for barley breeding. The relative height estimation of the canopy by UAV achieved high precision (up to r = 0.93) and repeatability (up to R2 = 0.98). In addition, we found a great overlap of detected significant genotypes between the reference heights and sensor-based heights. The yield prediction accuracy of both sensor systems was at the same level and reached a maximum prediction accuracy of r2 = 0.82 with a continuous increase in precision throughout the entire vegetation period. Due to the lower costs and the consumer-friendly handling of image acquisition and processing, the RGB imagery seems to be more suitable for yield prediction in this study.

Comprehensive evaluation of spring barley breeding lines in yield, stability and tolerance to biotic and abiotic factors under condition of the central part of the Ukrainian Forest-Steppe

Purpose. Identification of spring barley promising breeding lines with combination of adaptive traits under conditions of the central part of the Ukrainian Forest-Steppe. Methods. Field trial, laboratory-field analysis of drought tolerance, statistical and graphical analysis of experimental data. Results. The analysis of variance of the AMMI model showed that the largest contribution to the general variation (85.78%) had environmental conditions (years of research). The value of the genotype was 8.21%, and the genotype by environment interaction was 6.01%. The first and second principal components of both AMMI and GGE biplot explained more than 85% of the genotype-environment interaction. Spring barley breeding lines ‘Deficiens 5162’, ‘Nutans 5073’ and ‘Deficiens 5161’ had the superior combination of yield performance and relative stability through the years according to GGE biplot. With GYT biplot analysis it has been determined that the breeding lines ‘Deficiens 5162’ and ‘Nutans 5073’ also significantly predominated over the other genotypes in terms of combination of yield performance and a number of other traits – 1000 kernels weight, drought tolerance, resistance to pathogens. Breeding lines ‘Deficiens 5161’, ‘Nutans 4966’, ‘Nutans 4705’, ‘Nutans 4816’, ‘Nutans 5184’, ‘Nutans 5193’, which exceeded the mean value in the trial in terms of combination of yield performance and a number of adaptive traits may have practical significance in the breeding process for creation of new initial material. Conclusions. As a result of the complex evaluation when using AMMI, GGE biplot and GYT biplot graphical models the breeding lines ‘Deficiens 5162’ and ‘Nutans 5073’ with the optimal combination of yield, stability, thousand kernel weight and tolerance to abiotic and biotic environmental factors have been identified

SEARCH FOR THE SELECTION CRITERIA IN THE PROCESS OF SPRING BARLEY BREEDING IN DIFFERENT YEARS OF MOISTURE AVAILABILITY

На гибридах ярового ячменя поколений F1 и F2 изучены варьирование элементов структуры урожая и корреляционные взаимосвязи между ними. Цель исследования – поиск эффективных критериев отбора в селекции ярового ячменя на продуктивность колоса и растения. Полевые эксперименты проведены на чернозёмах лесостепи Среднего Поволжья в контрастные по гидротермическому режиму годы. Низким коэффициентом вариации (до 10 %) стабильно характеризовались высота растений, Кхоз главного колоса и Кхоз главного побега, средним (10-20%) – продуктивная кустистость, масса зерна главного колоса, Кхоз растения. Изменчивость остальных изученных элементов структуры урожая варьировала от низкой до средней. В год с достаточным увлажнением проявились три относительно обособленные корреляционные плеяды: продуктивность главного колоса, продуктивность растения, Кхоз, а также почти независимый от них признак «масса 1000 зёрен». В засушливый год произошло переопределение корреляционных связей между элементами, возникло сопряжение между признаками различных плеяд, увеличился вклад в продуктивность показателей массы 1000 зёрен и Кхоз. Сделан вывод о влиянии различных критериях отбора на продуктивность ячменя в благоприятных и засушливых условиях. В благоприятных условиях следует вести селекцию на длину главного колоса и число зёрен в нём. В засушливый год приобретают особенное значение масса 1000 зёрен и показатели Кхоз, которые являются самостоятельной целью селекции в любых условиях. При отборе селекционных линий и подборе родительских форм для скрещиваний необходимо опираться на данные, полученные в контрастные по погодным условиям годы. Variations in the elements of the yield structure and correlation relationships between them were studied using hybrids of spring barley of generations F1 and F2. The goal of the study is to search for effective selection criteria for productivity of a head and a plant in the process of spring barley breeding. Field experiments were carried out on chernozems of the forest-steppe of the Middle Volga region in years contrasting in the hydrothermal regime. The height of plants, Khoz of the main head and Khoz of the main shoot were consistently characterized by a low coefficient of variation (up to 10%), productive tillering, grain weight of the main head, Khoz of a plant by average (10-20%). The variability of the other studied elements of the yield structure varied from low to average. In the year with sufficient moisture, three relatively separate correlational constellations appeared: productivity of the main head, productivity of the plant, Khoz, as well as almost independent trait of “weight of 1000 grains”. In the dry year, there was a redefinition of the correlations between the elements, a conjugation between the characteristics of different constellations, and an increase of contribution to the productivity of indices of weight of 1000 grains and Khoz. The conclusion is made about the influence of various selection criteria on the productivity of barley under favorable and arid conditions. Under favorable conditions, it is necessary to select by the length of the main head and the number of grains in it. In a dry year, the weight of 1000 grains and indicators of Khoz acquire special importance, which are an independent goal of breeding under any conditions. When selecting breeding lines and selecting parental forms for crosses, it is necessary to rely on data obtained in years with contrasting weather conditions.