Barley Breeding Research Articles

Evaluating salinity tolerance in progeny of domestic and wild barley crosses at the seedling growth stage

AbstractSalinity is one of the most detrimental abiotic stresses affecting crop productivity worldwide. To identify barley (Hordeum vulgare L.) genotypes with satisfactory production under increased salinity, screening must focus on multiple phenological stages, specifically the earliest stages (germination and seedling), when plants are most vulnerable to stress. This experiment was conducted in a greenhouse to assess salinity tolerance of 161 genotypes (34 genotypes of 2× H. vulgare crosses; 116 genotypes of 4× H. vulgare crosses, and 11 parents). Beginning at the third leaf stage, seedlings were irrigated with solutions of 0, 100, 200, and 300 mM NaCl for 21 d. Analysis of variance showed significant effects due to genotype, salinity level, and their interaction for shoot dry weight (SDW). Overall, SDW showed negative association with plant height, whereas it was positively associated with tiller number, fertility, 100‐seed weight, and grain yield. Mean SDW of all families decreased as salinity treatment level increased. Families varied in SDW and salinity susceptibility index (SSI) at 300 mM salinity treatment. Diploid Families 2 and 3 had the greatest SDW and lowest SSI (<1). Thirty percent of crosses from tetraploid Family 2 yielded the greatest SDW, whereas the same proportion of crosses from tetraploid Family 4 showed the greatest salinity tolerance as measured by SSI. These crosses, as well as the female parents, are valuable germplasm for improving salinity tolerance in barley breeding programs.

Assessment of Genetic Diversity and Population Structure of Tunisian Barley Accessions (Hordeum vulgare L.) Using SSR Markers

In barley breeding programs, information about genetic dissimilarity and population structure is very important for genetic diversity conservation and new cultivar development. This study aimed to evaluate the genetic variation in Tunisian barley accessions (<em>Hordeum</em><em> </em><em>vulgare </em>L.) based on simple sequence repeat (SSR). A total of 89 alleles were detected at 26 SSR loci. The allele number per locus ranged from two to five, with an average of 3.4 alleles per locus detected from 32 barley accessions, and the average value of polymorphic information content was 0.45. A cluster analysis based on genetic similarity was performed, and the 32 barley resources were classified into five groups. Principal coordinates (PCoA) explained 12.5% and 9.3% of the total variation, and the PCoA was largely consistent with the results of cluster separation of STRUCTURE software analysis. The analysis of genetic diversity in barley collection will facilitate cultivar development and effective use of genetic resources.

Leaf rust resistance in barley accessions from Ethiopia

Currently, the problem of broadening the diversity of cultivated barley varieties based on the effective genes for resistance to the leaf rust causal agent Puccinia hordei has become relevant. In 2018–2019 the resistance of 925 barley accessions from Ethiopia to the northwestern (St. Petersburg, Pushkin) pathogen population was evaluated. The accessions were sown at a later date, favoring to severe plant damage. The resistance was assessed during the heading period and over the milk ripening stage using a point scale. The results of the experiments have indicated a low diversity of Ethiopian barley according to the studied trait. Only 4 accessions have been resistant to P. hordei, and 3 breeding lines (k-30810, k-30811 and k-30812) have been protected by the previously identified Rph7 gene, which efficiency has been decreasing
 in recent years. The accession k-21919 has possessed a high level of resistance to the pathogen (i.e. lack of damage symptoms) and therefore it can be recommended for utilization in barley breeding.

Yield Stability and Physiological Parameters of Barley (Hordeum vulgare L.) Genotypes under Rainfed Conditions

The development of barley (Hordeum vulgare) genotypes over its life cycle depend on a number of environmental abiotic stress factors. Grain losses are often caused by high or low temperatures, drought, and such soil structure. The research was carried out to investigate the yield, stability, some quality, and physiological characteristics of some advanced barley genotypes under rainfed conditions. This research was established with 25 genotypes, in randomized complete blocks design with four replications at 3 locations in 2012-2013 growing years. Grain yield, plant height, days of heading, biomass, canopy temperature, 1000-kernels weight, and test weight was investigated. There were significant differences among the genotypes. Based on location, the highest yield was determined in Tekirdağ location. Cultivar Harman had higher yield potential. The highest biomass was measured for cultivars Harman and Lord and the lowest canopy temperature was measured for the G21 line. Earliness in terms of growing forage crops in the same growing year and short plant height for lodging resistance are very important characters in the Trakya region. G11 and G16 were early, and G6, G7, and G16 were the shortest genotypes. The highest 1000 kernels weight was measured in G3, and test weight in G19 lines. It was determined that cultivar Harman and 5 lines G7, G9, G22, G24, and G25 were well adapted to all environmental conditions. Genotypes Sladoran, G18, G3, and G8 were well adapted to fertile environmental conditions. Canopy temperature negatively affected and reduced grain yield, biomass, test weight, 1000-kernel weight, and protein ratio under rainfed conditions. The result of the study suggested that canopy temperature could be used in a barley breeding program for physiological parameters under rainfed conditions.

The study results of the world collection of hullless barley according to grain quality in the south of the Rostov region

The current paper has presented the study results of the collection varieties of hull-less spring barley according to grain quality indices (protein, starch, lysine and ß-glucan). The initial material for the for the varieties' study in the conditions of the south of the Rostov region were than 100 varieties and lines of hull-less barley developed in the Federal State Budgetary Scientific Institution “FRC All-Russian Institute of Plant Genetic Resources named after N. I. Vavilov”. The study was carried out in the crop rotation of the department of barley breeding and seed production of the FSBSI “Agricultural Research Center “Donskoy” in 2016-2018. The purpose of the study was to scrutinize quality indices of the hull-less barley varieties. The trials were carried out according to the Methodology of the State Variety Testing. The accounting area of the plot was 10 m 2 , the seeding rate was 450 germinating grains per 1 m 2 , the standard variety ‘Ratnik’ was sown in 20 numbers with single sequence. The sowing was carried out with the seeder Wintershteiger Plotseed S; the harvesting was conducted with the combine Wintershteiger-Classik. The qualitative indices were determined according to generally accepted GOST standards. During the study under contrasting weather conditions, there have been identified the samples with increased indices of protein, lysine, starch and ß-glucan. In 2016 the variety ‘Golozerny’ (RF) was characterized by a high content of lysine and ß-glucan. In 2018 the samples ‘K-3800’ (Ukraine) and ‘Nigohodaka’ (Japan) combined a high content of several indices. Throughout three years of study, according to seed protein percentage, there has been identified the sample ‘Nigohadaka’ (Japan), which showed consistently high values of this trait. According to starch content there has been identified the sample ‘CDC Dawn’ (Canada). During the years of study, it was possible to trace that there were the advantages of hull-less samples according to quality indices over the unhulled standard variety. There could be made the conclusion that hull-less barley can be used in hybridization to improve quality.

A High-Density Genetic Linkage Map of SLAFs and QTL Analysis of Grain Size and Weight in Barley (Hordeum vulgare L.).

Grain size is an important agronomic trait determines yield in barley, and a high-density genetic map is helpful to accurately detect quantitative trait loci (QTLs) related to grain traits. Using specific-locus amplified fragment sequencing (SLAF-seq) technology, a high-density genetic map was constructed with a population of 134 recombinant inbred lines (RILs) deriving from a cross between Golden Promise (GP) and H602, which contained 12,635 SLAFs with 26,693 SNPs, and spanned 896.74 cM with an average interval of 0.07 cM on seven chromosomes. Based on the map, a total of 16 QTLs for grain length (GL), grain width and thousand-grain weight were detected on 1H, 2H, 4H, 5H, and 6H. Among them, a major QTL locus qGL1, accounting for the max phenotypic variance of 16.7% was located on 1H, which is a new unreported QTL affecting GL. In addition, the other two QTLs, qGL5 and qTGW5, accounting for the max phenotypic variances of 20.7 and 21.1%, respectively, were identified in the same region, and sequencing results showed they are identical to HvDep1 gene. These results indicate that it is a feasible approach to construct a high-quality genetic map for QTL mapping by using SLAF markers, and the detected major QTLs qGL1, qGL5, and qTGW5 are useful for marker-assisted selection (MAS) of grain size in barley breeding.

Identification of Spring Barley Breeding Lines With Superior Yield Performance and Stability

The aim of the present study was to substantiate theoretically and to test in practice scheme of multi-environment trials at the final stage of spring barley breeding process and to distinguish the genotypes which combine superior yield performance and stability. In the first year of competitive testing (2015) nine promising spring barley breeding lines have been selected under condition of the Central part of Forest-Steppe of Ukraine (latitude 49°64′, longitude 31°08′, altitude 153 m). In 2016 and 2017, the genotypes were additionally tested in two other different agro-climatic zones of Ukraine: Polissia (latitude 50°93′, longitude 31°69′, altitude 126 m) and Northern Steppe (latitude 48°56′, longitude 32°32′, altitude 171 m). In addition to the standard variety Vzirets, the breeding lines were compared with ten widespread spring barley varieties in agricultural production. Significant total yield variability of the genotypes and cross-over genotype by environment interaction has been revealed. It confirmed the validity of proposed combination of spatial (zones) and temporal (years) gradients for more efficient evaluation of the genotype by environment interaction and differentiation of genotypes in terms of yield performance and stability. As a practical result, using additive main effects and multiplicative interaction (AMMI) and genotype main effects plus genotype by environment interaction (GGE) models, four spring barley breeding lines with combination of superior yield performance and high stability have been identified.

Traits discovery in Hordeum vulgare sbsp. spontaneum accessions and in lines derived from interspecific crosses with wild Hordeum species for enhancing barley breeding efforts

AbstractBarley is a crop of global significance with multiple uses (feed, food and beverages), but its productivity worldwide is limited by several abiotic and biotic stresses. Crop wild relatives, exclusively, Hordeum vulgare ssp. spontaneum and H. bulbosum, are important genetic resources needed to develop new adapted varieties. A total of 117 accessions of H. spontaneum from different origins and 145 lines derived from crosses between barley and H. bulbosum supplied by NordGen were evaluated for field reactions to four major diseases. In addition, a set of 45 lines derived from interspecific crosses with H. spontaneum and H. bulbosum along with 10 checks were evaluated for agronomic traits and yield performance under four different environmental conditions and for quality attributes. The results showed that 37.7%, 71.6%, 15.1%, and 79.5% of H. spontaneum accessions were resistant to moderately resistant to net form net blotch, scald, leaf rust and powdery mildew, respectively, while the respective percentages in case of H. bulbosum derivatives were 31%, 20.4%, 17.9% and 70.6%. Only three accessions of H. spontaneum showed high resistance levels to the four diseases while 23 other accessions and 16 H. bulbosum derived lines showed resistance to a combination of two to four diseases. When H. bulbosum and H. spontaneum derived lines were evaluated under different environments, none of them gave higher grain yield and higher thousand kernel weight than the best checks. However, a few H. bulbosum derived lines showed higher straw yield, and lines combining tall stature, and lodging resistance were identified. Pre‐breeding efforts need to be strengthened further by evaluating more wild Hordeum accessions, their crossing with the best available parents and selection of elite germplasm to be made available to barley breeding programs for the development of new adapted and high yielding varieties.

Genotype-by-environment interaction analysis for grain yield of barley genotypes under dryland conditions and the role of monthly rainfall

In rainfed areas, due to the many variable environmental factors, the introduced cultivars, in addition to high yield, must also have yield stability. In the present study, 15 barley lines along with three local control cultivars under dryland conditions in six cold locations of Iran during three consecutive years (2013–2016) were evaluated. The results showed that the genotype-by-environment interaction is highly significant. The ratios between the sums of squares of G, GE and IPCA1 indicated that the AMMI model is suitable for data analysis. Also, combining AMMI model with BLUP technique and using WAASB index was promising and the results of both were in agreement. With the AMMI1 model, three mega-environments were determined, and the locations of Maragheh, Qamlu and Zanjan were located in the same mega-environment every three years. Finally, it was concluded that the second control cultivar was the most desirable genotype for most environments. Genotypes 16, 15 and 12 with high yield and optimal stability have the ability to be used as new potential genetic resources for improving and stabilizing grain yield in barley breeding programs for cold rainfed conditions. Genotypes 4, 5, and 6 should only be used in narrow adaptation to restricted environments. On the other hand, rainfall in November and January is important for proper seedling establishment, and rainfall in April and May is important for pollination and grain filling period.

High-resolution mapping of Rym14Hb, a wild relative resistance gene to barley yellow mosaic disease

Key messageWe mapped the Rym14Hb resistance locus to barley yellow mosaic disease in a 2Mbp interval. The co-segregating markers will be instrumental for marker-assisted selection in barley breeding.Barley yellow mosaic disease is caused by Barley yellow mosaic virus and Barley mild mosaic virus and leads to severe yield losses in barley (Hordeum vulgare) in Central Europe and East-Asia. Several resistance loci are used in barley breeding. However, cases of resistance-breaking viral strains are known, raising concerns about the durability of those genes. Rym14Hb is a dominant major resistance gene on chromosome 6HS, originating from barley’s secondary genepool wild relative Hordeum bulbosum. As such, the resistance mechanism may represent a case of non-host resistance, which could enhance its durability. A susceptible barley variety and a resistant H. bulbosum introgression line were crossed to produce a large F2 mapping population (n = 7500), to compensate for a ten-fold reduction in recombination rate compared to intraspecific barley crosses. After high-throughput genotyping, the Rym14Hb locus was assigned to a 2Mbp telomeric interval on chromosome 6HS. The co-segregating markers developed in this study can be used for marker-assisted introgression of this locus into barley elite germplasm with a minimum of linkage drag.

Genetic and Agro-morphological diversity in global barley (Hordeum vulgare L.) collection at ICARDA

Heat stress at later growth stage is one of the major limitations in achieving potential yield in barley. Incorporation of heat tolerance in the variety development process is an essential task that breeders would like to achieve by exploring new sources of genetic variability and their utilization. A better understanding of genetic variation in existing genotypes under heat stress is required to produce high yielding varieties with improved heat tolerance. An association mapping panel 2017 (AM2017), comprising of 316 genotypes, was evaluated under timely and late sown (heat stress) conditions for two consecutive crop seasons at Hisar in India during 2017–2019. Eight agro-morphological traits, mainly contributing to yield, were considered agro-morphological diversity study. Genetic diversity and population structure were explored by using the 50 K iSelect Illumina Barley SNP array. A set of 36,793 SNP markers, covering a genetic distance of 991.82 cM with an average marker density of 37.09 SNPs/cM, was obtained after quality filtration. The gene diversity (GD) and Polymorphic Information Content (PIC) at genome level was 0.362 and 0.289, respectively. In AM2017, two subpopulations were observed mainly due to the row types. Principal component analysis of agro-morphological traits revealed that days to heading and maturity along with spike length, spikelet number per spike and grain yield per plot were the most important traits in timely and late sown conditions. The information on agro-morphological genetic diversity under heat stress conditions will be useful in identifying heat tolerant genotypes for use in barley breeding programs.

The influence of breeding history, origin and growth type on population structure of barley as revealed by SSR markers

Natural and mass selection during domestication and cultivation favored particular traits of interest in barley. In the present study, population structure, and genetic relationships among 144 accessions of barley landraces and breeding materials from various countries were studied using a set of 77 and 72 EST-SSR and gSSR markers, respectively distributed on seven chromosomes of barley. In total, 262 and 429 alleles were amplified in 77 EST-SSRs and 72 gSSR loci, respectively. Out of which, 185 private/group-specific alleles were identified in the landraces compared with 14 in "cultivar and advanced breeding lines", indicating the possibility to introgress favorite alleles from landraces into breeding materials. Comparative analysis of genetic variation among breeding materials, Iranian landraces, and exotic landraces revealed higher genetic diversity in Iranian landraces compared with others. A total of 37, 15, and 14 private/group-specific alleles were identified in Iranian landraces, exotic landraces, and breeding materials, respectively. The most likely groups for 144 barley genotypes were three as inferred using model- and distance-based clustering as well as principal coordinate analysis which assigned the landraces and breeding materials into separate groups. The distribution of alleles was found to be correlated with population structure, domestication history and eco-geographical factors. The high allelic richness in the studied set of barley genotype provides insights into the available diversity and allows the construction of core groups based on maximizing allelic diversity for use in barley breeding programs.

Resistance of Two-Rowed Barley Cultivars and Collection Accessions to False Loose Smut in Western Siberia

False loose smut caused by the fungus Ustilago nigra Tapke causes significant damage to barley crops in Russia. The aim of this work was to estimate the false loose smut resistance in spring double-row barley varieties created by the Omsk Agrarian Research Center and samples from the Collection of the Vavilov All-Russia Institute of Plant Genetic Resources (VIR) in Western Siberia. Cultivars were assessed in the field in 2016–2019 according to common methods. The artificial inoculation of seeds with U. nigra teliospores was carried out before sowing. The damage to cultivars significantly varied, which was due to contrasting weather conditions during periods critical for plant infection. Stable resistance to disease was observed for cultivars Omsky 91 and Sasha, while damage to other cultivars of Omsk breeding increased. The collection cultivars of Russian and Western European breeding showed high resistance to false loose smut under conditions favorable for infection, as well as in drought with high temperatures. Ukrainian and Latvian cultivars showed high resistance to infection under conditions of high humidity and low temperature. High resistance under contrasting conditions was observed for cultivars Vorsinsky 2, Yasny, Vakula, Zadel 3, Yastreb, Inklyuziv, and Vzirez. The best combination of resistance to the disease and yields were demonstrated by cultivars Vorsinsky 2, Zernogradsky 770, Vakula, Vzirets, and Inklyuziv. These cultivars are promising to be used as sources of false loose smut resistance for barley breeding in Western Siberia.

The Effect of Pesticide Application on QTLs Controlling Traits in Barley

Among cereals, barley (Hordeum vulgare L.) ranks fourth in consumption worldwide. Among barley breeding goals, one can refer to gene mapping, studying their inheritance, and saturated genetic linkage maps. Problems with pesticide applications include reduced genetic diversity, reduced nitrogen fixation, and destruction of the habitat of especially endangered species. The effect of pesticide application on the emergence of QTLs expressing traits in experimental barley was investigated using 104 barley F2:4 families from Badia × Kavir cross. A total of 25 QTLs were mapped for all traits. In non-using pesticides, 12 QTLs were identified for peduncle length, stem diameter, flag leaf length, and awn length. It was found that qFL-4 has major effects on flag leaf length. or using the pesticide, 13 QTLs were detected that QTLs related to stem diameter, grain weight, flag leaf length explained a high percentage of phenotypic variation. The results of this study showed that pesticide application affects the expression of some genes in barley. Besides, major-effect trait-controller QTLs and their associated markers can be used in marker-assisted selection (MAS) programs.

Sources of characters useful for breeding in hulless barley

Background. In the present-day situation, the problems pertaining to the nutritional quality of food and feed are quite pertinent for fodder production and cereal farming. The prospect to exploit hulless barley is regarded as a promising trend of agricultural research, because its grain contains chemical compounds of higher value than those in hulled barley. However, among the limiting factors of hulless barley cultivation, low yield should be mentioned, along with poor lodging resistance and susceptibility to fungal diseases. Therefore, the task of searching for and comprehensive studying of source material for hulless barley breeding is essential as the first step towards the development of high-yielding and adaptable cultivars.Materials and methods. Twenty hulless barley accessions, representing 15 botanical varieties, served as the target material for the study. Their genotypes were evaluated in the northern forest steppe environments of Tyumen Province (2015– 2017) according to the guidelines developed by the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) and field trial methods by B. A. Dospekhov. Correlation analysis was used for statistical processing of experimental data.Results and conclusion. The degree of interactions between the studied characters was measured, and their effect size in the formation of the yield was shown for hulless barley accessions. An inverse correlation of medium strength (r = –0.37) was observed between plant height and lodging resistance, and a direct relationship between plant height and yield was recorded (r = 0.37). The yield was most closely associated with grain weight per plant (r = 0.61) and 1000 grain weight (r = 0.54). The research results showed that C.I.10975 (k-30624, Ethiopia), Liguleless (k-29894, Tajikistan), Schwarze Nackte Kraftborn (k-25788, Germany) and ‘De printempe’ (k-23491, France) had relatively high yield combined with a number of other useful traits.

Identification, gene expression and genetic polymorphism of zinc finger A20/AN1 stress-associated genes, HvSAP, in salt stressed barley from Kazakhstan

BackgroundA family of genes designated as the Zinc finger A20/AN1 Transcription factors encoding stress-associated proteins (SAP) are well described in Arabidopsis and rice, and include 14 AtSAP and 18 OsSAP genes that are associated with variable tolerances to multiple abiotic stresses. The SAP gene family displays a great diversity in its structure and across different plant species. The aim of this study was to identify all HvSAP genes in barley (Hordeum vulgare L.), to analyse the expression of selected genes in response to salinity in barley leaves and develop SNP marker for HvSAP12 to evaluate the association between genotypes of barley plants and their grain yield in field trials.ResultsIn our study, 17 HvSAP genes were identified in barley, which were strongly homologous to rice genes. Five genes, HvSAP5, HvSAP6, HvSAP11, HvSAP12 and HvSAP15, were found to be highly expressed in leaves of barley plants in response to salt stress in hydroponics compared to controls, using both semi-quantitative RT-PCR and qPCR analyses. The Amplifluor-like SNP marker KATU-B30 was developed and used for HvSAP12 genotyping. A strong association (R2 = 0.85) was found between KATU-B30 and grain yield production per plant of 50 F3 breeding lines originating from the cross Granal × Baisheshek in field trials with drought and low to moderate salinity in Northern and Central Kazakhstan.ConclusionsA group of HvSAP genes, and HvSAP12 in particular, play an important role in the tolerance of barley plants to salinity and drought, and is associated with higher grain yield in field trials. Marker-assisted selection with SNP marker KATU-B30 can be applied in barley breeding to improve grain yield production under conditions of abiotic stress.

Genome-wide association analysis of natural variation in seed tocochromanols of barley.

Tocochromanols (tocols for short), commonly called Vitamin E, are lipid-soluble plant antioxidants vital for regulating lipid peroxidation in chloroplasts and seeds. Barley (Hordeum vulgare L.) seeds contain all eight different isoforms of tocols; however, the extent of natural variation in their composition and their underlying genetic basis is not known. Tocol levels in barley seeds were quantified in diverse H. vulgare panels comprising 297 wild lines from a diversity panel and 160 cultivated spring-type accessions from the mini-core panel representing the genetic diversity of the USDA barley germplasm collection. Significant differences were observed in the concentration of tocols between the two panels. To identify the genes associated with tocols, genome-wide association analysis was conducted with single nucleotide polymorphisms (SNPs) from Illumina arrays for the mini-core panel and genotyping-by-sequencing for the wild barley panel. Forty unique SNPs in the wild barley and 27 SNPs in the mini-core panel were significantly associated with various tocols. Marker-trait associations (MTAs) were identified on chromosomes 1, 6, and 7 for key genes in the tocol biosynthesis pathway, which have also been reported in other studies. Several novel MTAs were identified on chromosomes 2, 3, 4 and 5 and were found to be in proximity to genes involved in the generation of precursor metabolites required for tocol biosynthesis. This study provides a valuable resource for barley breeding programs targeting specific isoforms of seed tocols and for investigating the physiological roles of these metabolites in seed longevity, dormancy, and germination.

Comparative de novo transcriptome analysis of barley varieties with different malting qualities

Barley is one of the most important crops in the world. Barley is used as both food and feed and is important for malt production. Demands for malting quality differ among countries and customs. Malting quality is a complex characteristic involving barley genetics, the environmental conditions during barley growth, and the technological parameters of the malting process. In this study, the hypothesis was that there were no differences between two groups of barley varieties with different but defined malting qualities, which was tested using RNA sequencing during selected stages of malting. In total, 919 differentially transcribed genes between the two barley groups were identified and annotated. Differentially expressed genes (DEGs) were primarily assigned to gene ontology (GO) terms of oxidation-reduction process - oxidoreductase activity, response to stress, carbohydrate metabolic process, and proteolysis - hydrolase activity, and metal ion binding. Genes connected with the plasma membrane and its integral components also play important roles in malting quality. DEG profiles of selected genes in the three malting stages indicate a complex character of malting quality. Many single-nucleotide polymorphisms (SNPs) and insertions and deletions (indels) were identified. SNPs and indels with the best quality were used for primer design. After optimization and validation, five molecular markers were developed for use in barley breeding.

Fast and Inexpensive Phenotyping and Genotyping Methods for Evaluation of Barley Mutant Population.

To further develop barley breeding and genetics, more information on gene functions based on the analysis of the mutants of each gene is needed. However, the mutant resources are not as well developed as the model plants, such as Arabidopsis and rice. Although genome editing techniques have been able to generate mutants, it is not yet an effective method as it can only be used to transform a limited number of cultivars. Here, we developed a mutant population using ‘Mannenboshi’, which produces good quality grains with high yields but is susceptible to disease, to establish a Targeting Induced Local Lesions IN Genomes (TILLING) system that can isolate mutants in a high-throughput manner. To evaluate the availability of the prepared 8043 M3 lines, we investigated the frequency of mutant occurrence using a rapid, visually detectable waxy phenotype as an indicator. Four mutants were isolated and single nucleotide polymorphisms (SNPs) were identified in the Waxy gene as novel alleles. It was confirmed that the mutations could be easily detected using the mismatch endonuclease CELI, revealing that a sufficient number of mutants could be rapidly isolated from our TILLING population.

Implications of intra-seasonal climate variations on chlorophyll a fluorescence and biomass in winter barley breeding program

This study aimed to explore how ten selected winter barley genotypes responded to variations in environmental conditions during the growth season by using fast chlorophyll a fluorescence and normalized difference vegetation index (NDVI) at the booting, anthesis and early grain-filling stage. Lower amount of rainfall during the anthesis induced instability in the function of PSII, observed as the positive K-band in six and the positive L-band in seven genotypes. At grain filling, all genotypes displayed negative K- and L-bands, suggesting an increase of stability within PSII. The performance index increased from booting to grain filling in most genotypes. Chlorophyll a fluorescence parameters were incorporated into the partial least squares model as explanatory variables of NDVI. After a cross-validation, the model with four latent variables was chosen explaining 75.8% variance (r = 0.870) for NDVI. The principal component analyses showed two distinct types of the reaction of the barley genotypes to the mild drought stress at anthesis.