Genetic variation among selected pure lines from Turkish barley landrace ‘Tokak’ in yield-related and malting quality traits

Aim of study: Improvement of barley cultivars for malting traits suffers from narrow genetic pool in barley for these traits. Landraces are resources that could be used for this purpose. The present study was conducted to determine the variation for malting quality traits within a Turkish barley landrace. Area of study: The study was undertaken in Tokat, a province in Black Sea Region of Turkey. Material and methods: Twenty-five diverse lines, out of 42 unique genotypes previously identified in ‘Tokak’ landrace (PI 470281) based on DNA markers, were evaluated for malting quality traits along with the malting barley cv. ‘Tokak 157/37’ in four field trials. Thousand-seed weight, test weight, grain yield, lodging, malt extract percentage, diastatic power, alpha amylase and malt beta glucanase activities, malt protein and starch contents were determined. Main results: Principal component analysis of malting quality traits revealed that thousand-seed weight, alpha amylase activity, beta glucanase activity and diastatic power were the most discriminatory traits for the lines. As the average of four trials, 15 of the 25 lines evaluated had higher grain yields and 10 of 25 lines had higher malt extract percentages than the standard cultivar ‘Tokak 157/37’. Malt extract was highest in Line 59 in all environments, and this line also had the highest values for beta glucanase activity and starch content. Line 215 had highest values for alpha amylase activity. Lines 59 and 215 clearly had superior malting quality. Research highlights: These lines could harbor novel alleles for these traits to be used in malting barley improvement.

Genetic Diversity in 19th Century Barley (Hordeum vulgare) Reflects Differing Agricultural Practices and Seed Trade in Jämtland, Sweden

Landrace crops are important genetic resources, both for plant breeding efforts and for studying agrarian history. The distribution of genetic diversity among landraces can reflect effects of climate, economic structure, and trade also over a limited spatial and temporal scale. In this study, we have SNP genotyped historical barley seed samples from the late 19th century, together with extant barley landrace accessions from Jämtland, Sweden, a county centrally located, situated between Sweden and Norway. We found two main genetic clusters, one associated with the main agricultural district around lake Storsjön and one in the peripheral areas. Data was also compared with genotypes from landraces from across the Scandinavian peninsula. Accessions from the peripheral part of Jämtland show genetic similarity to accessions from a large part of central Scandinavia, while the accessions from the Storsjön district are more differentiabted. We suggest that these dissimilarities in genetic diversity distribution are explained by differences in the relative importance of agriculture and trading. We further compared the historical material with ex situ preserved extant landraces from the same region and found that their genetic diversity was not always representative of the given provenience. The historical material, in contrast, proved particularly valuable for assessing how crop genetic diversity has historically been influenced by economic focus.

Variation and Stability in Agronomic Traits Among Geographic Groups of Traditional Landraces Grown Under High Yielding Conditions

Future crop production needs to deliver increased yields with less agronomic inputs in the face of increasingly variable climate, which is predicted to result in greater seasonal variation in production. To support more sustainable production, new crop varieties need to have increased resilience in their agronomic traits to cope with fluctuation in growing conditions. We investigated the breadth of phenotypic expression in yield related agronomic traits among groups of European barley landrace from different geographic origin and Harlan composite cross populations grown under a common high yield test protocol. Stability of agronomic traits and yield were assessed for each group across environments and years. There were significant differences in thousand grain weight (TGW), seeds per ear and shoot production (tillering) among landrace groups and between 2 or 6 rowed ear habit. Modern cultivars and, to a lesser extent, Harlan populations had significantly more stable TGW than other groups. Traits most strongly associated with yield stability in 2 rowed landraces were TGW and tillering, whilst in 6 rowed landraces tillering, ear length and plant height were associated with stable yield. Absence of significant difference in agronomic trait stability among landrace groups was attributed to high phenotypic variation within groups. We conclude that phenotypic variation and stability in agronomic traits among barley landraces could be exploited for enhancing resilience in future crop breeding.

Identifying potential novel resistance to the foliar disease ‘Scald’ (Rhynchosporium commune) in a population of Scottish Bere barley landrace (Hordeum vulgare L.)

Barley ‘Scald’ is an economically damaging fungal disease that is a global problem, causing significant yield and economical losses in the UK barley feed and malting industries. Presently, a limited number of Rhynchosporium resistance genes exist, but selective pressures on the fungi cause the demand for new sources of resistance. Landraces, such as the Scottish Bere barley, hold potential sources of resistance that can be utilised, with farmers providing anecdotal evidence of resistance in field populations of Bere. This study analysed 131 heritage cultivars and landrace lines, including 37 Bere lines, to screen for resistance using both detached leaf assays (DLAs) and field experiments. Results showed that Bere lines produced smaller, but more necrotic, lesions for the majority of isolates in the DLAs, as well as smaller scores when visually assessed in field conditions. Whilst the infection patterns of the lines differed between isolates and experimental conditions, three Bere lines were identified as consistently showing reduced levels of infection (45 A 23, 58 A 36 Eday, and 8-125). Using genome-wide association analysis, we were able to identify a number of genomic regions associated with reduced infection symptoms, four in regions associated with known resistance genes, but another four associated with new regions that contain promising candidate genes. Further analysis of these new regions and candidate genes should be undertaken to identify targets for future disease-resistance breeding.

Phenotypic response of barley landrace and its wild progenitor Hordeum spontaneum from Jordan to salt stress

Populations of barley landrace [Hordeum vulgare (L.)] and wild barley progenitor [Hordeum spontaneum (L.)] were collected from 13 diverse eco-geographical regions in Jordan. In addition to two check varieties (Rum and Acsad 165) were collected from farmers’ fields. In total, 28 genotypes were evaluated during germination, early seedling and maturity stages for salt tolerance. Barley populations were exposed to tap water of 0.85 dS m-1 and saline solutions (NaCl, CaCl2 and MgSO4) of 4, 8, 12 and 16 dS m-1. Final germination percentage, the lengths of shoot and seminal root, growth and yield related traits were significantly decreased by increasing the level of salinity. Proline content was increased by increasing the level of salinity. A high level of salinity of 16 dS m-1 had a strong impact on reduction of grain yield and other agronomic traits in the examined populations. A considerable variation among populations was detectable. Barley landrace and wild barley that were collected from Tafila region were the most tolerant grown populations in Jordan. Interestingly, the ranking pattern of these two populations at the germination and seedling related-traits was consistent with the ranking pattern at the maturity phase. In conclusion, this study indicates that barley landrace and wild barley populations are potential donors for genes of salt tolerance that can be used to enhance salinity tolerance in barley.

Morphological Characteristics of Two-rowed Barley (Hordeum sativum ssp. distichum L.) Landraces Originating from Herzegovina

Barley is a small grain cereal, tolerant to high temperatures and drought. Due to this characteristic, it can be regarded as a promising crop for production in dry conditions. Research on five spring landraces of two-rowed barley lasted two experimental years (2011 and 2012) in agro-ecological conditions of Banja Luka. In the experiment, the standard cropping practices were applied, without irrigation. The experiment was set as a complete randomized design with four replications. All measurements were performed in 10 plants per replication. Morphological characteristics included plant height (cm), spike length (cm), grain number per spike and grain weight per spike (g). Obtained data were subjected to two-way analysis of variance with landrace and growing season as main factors. Significant treatment or interaction effects were further analysed by Fisher's least significant difference (LSD) test, often utilized for pairwise comparisons among arithmetic means. In all tested traits the maximum average values were obtained in barley landrace AM2, i.e. the plant height (86.89 cm), the spike length (8.90 cm), the grain number per spike (24.74) and the grain weight per spike (1.17 g). Due to these facts, two-rowed barley landrace AM2 can be marked as the most productive in this research, bearing a potential for different crop breeding practices.

Changes in barley (Hordeum vulgare L. subsp. vulgare) genetic diversity and structure in Jordan over a period of 31 years

In many regions of the world, the cultivation of landraces is still common, in particular in centres of crop diversity. Significant effort has been put into ex situ conservation of landraces but limited data exist on the changes in genetic diversity that occur over time in farmers’ fields. We assessed temporal changes in barley landrace diversity in Jordan using seed samples collected in 1981 and 2012 from the same locations. We did not observe significant changes in the amount of genetic diversity, but samples collected in 2012 were more homogenous and less locally distinct. In two sites, we observed replacement of the old material. We observed a change in phenotype, and phenotypes were found to be more homogeneous among sites in 2012. Climate changed significantly over the study period, becoming hotter and dryer, but we did not identify any correlation between the changes in climate and genetic and phenotypic variations. While the amount of genetic diversity in terms of allelic richness and number of multi-locus genotypes has been maintained, local distinctiveness among landrace barley populations in Jordan was reduced.