VARIABILITY, HERITABILITY, AND CORRELATIONS AMONG GRAIN YIELD AND RELATED TRAITS IN HULLESS BARLEY ACCESSIONS

The aim of the present study was to investigate the variability, heritability and correlation between grain yield and yield-related traits of hulless accessions of spring barley under Southeast Bulgarian conditions. The research work was conducted in the experimental field of the Institute of Agriculture - Karnobat, South-eastern Bulgaria during the 2016 and 2017 growing seasons. The trail consisted of 20 six-rowed hulless barley accessions from ICARDA. A significant variation of grain yield and yieldrelated traits among the studied hulless barley accessions was found. The values of broad-sense heritability were from 1.81% for grain yield to 81.84% for the number of spikelets per spike. The number of spikes per plant had a direct positive effect on grain yield of hulless spring barley in both growing seasons. In a condition of water stress (the second year of study), the weight of grains per spike shows the highest direct effect on grain yield. Since the number of spikes per plant and weight of grains per spike had low heritability, these traits can be used as additional traits for selection for improving grain yield in the hulless barley breeding program of hulless barley only if the selection be practiced in later generations in replicated trials

GENETIC DIVERSITY IN SODIUM AZIDE-INDUCED BARLEY MUTANT LINES

The aim of this study was to assess the diversity among sodium azide-induced mutants of winter 2-rowed barley for 8 quantitative traits of by multivariate analyses. Forty-seven mutant lines and their parental varieties Kuber, Zagorets, Asparuh, and Imeon were tested in complete block design with four replications. The studied traits included spike length, awn length, peduncle length, spikelet and grain number per spike, grain weight per spike, 1000 grain weight and grain yield. Principal component and cluster analyses were used for the assessment of mutants. Traits spike length, spikelet number per a spike, grain number per spike and grain weight per spike had the largest contribution to the divergence between mutants. The cluster and principal component analyses employed in the present study divided the mutant lines into different groups, which were deviated significantly from the respective parents. Diverse mutant lines with improved yield-related traits suitable for including in winter barley breeding program were identified.</jats:p

HERITABILITY AND GENETIC ADVANCE OF YIELD AND YIELD RELATED TRAITS IN WINTER FEED BARLEY VARIETIES

A field experiment was conducted at the Institute of Agriculture – Karnobat, Southeastern Bulgaria in three growing seasons. Twenty barley varieties were laid out in a complete block design with 4 replications. Variability, heritability and genetic advance for yield-related traits and grain yield were studied. There were significant differences among varieties for all studied traits including grain yield. Heritability in broad sense ranged from 10.10% for grain yield to 94.60% for spike length. High heritability estimates and genetic advance as percent of mean was computed for spike length and 1000 grain weight. Besides, genotypic coefficient of variance and phenotypic coefficient of variance had low differences for these characters. Therefore, these traits could be easily improved by selection. Grain yields of the check varieties Veslets and Izgrev were 5.27 t/ha and 5.09 t/ha, respectively. The varieties that performed better than the checks for grain yield were PA86-49-95 (6.43 t/ha), Bojin (6.01 t/ha), and Express (5.90 t/ha). Hence, using these varieties in the breeding program of winter feed barley could lead to the improvement of grain yield.</jats:p

Variability, heritability, and correlations among grain yield and related traits in hulless barley accessions

The aim of the present study was to investigate the variability, heritability and correlation between grain yield and yield-related traits of hulless accessions of spring barley under Southeast Bulgarian conditions. The research work was conducted in the experimental field of the Institute of Agriculture - Karnobat, South-eastern Bulgaria during the 2016 and 2017 growing seasons. The trail consisted of 20 six-rowed hulless barley accessions from ICARDA. A significant variation of grain yield and yield-related traits among the studied hulless barley accessions was found. The values of broad-sense heritability were from 1.81% for grain yield to 81.84% for the number of spikelets per spike. The number of spikes per plant had a direct positive effect on grain yield of hulless spring barley in both growing seasons. In a condition of water stress (the second year of study), the weight of grains per spike shows the highest direct effect on grain yield. Since the number of spikes per plant and weight of grains per spike had low heritability, these traits can be used as additional traits for selection for improving grain yield in the hulless barley breeding program of hulless barley only if the selection be practiced in later generations in replicated trials.</jats:p

Grain quality of mutant lines of six-rowed barley

Abstract. The aim of this study was to assess the variation in grain quality traits among mutant lines of winter feed barley. Nine mutant lines derived from the advanced breeding line Kt3029 and 10 mutant lines derived from variety GA-Luttrell along with their parent forms were evaluated. The study was conducted at the Institute of Agriculture – Karnobat during the period 2015-2017. Test weight, 1000-grain weight, the content of protein, starch, lysine, fat, ash, and fibre were determined. Significant differences between the mutant lines and the parent forms for the studied traits were observed. Significantly higher protein content compared to parent was found in the grain of mutant lines 22/1-5, 22/2-10 and 22/1-12 from line Kt3029 and 26/1-1, 26/1-3 and 26/2-11 from variety GA-Luttrell. The grain of mutant line 26/2-12 had the best combination of protein and starch. Mutant lines 22/1-11 and 22/1-12 from Kt3029 and 26/1-1, 26/2-1 and 26/2-12 from variety GA-Luttrell showed a good combination between protein content and 1000-grain weight. Those mutant lines can be included in the breeding program for the development of varieties with improved feed quality.</jats:p

GRAIN QUALITY OF MUTANT LINES INDUCED IN MALTING BARLEY VARIETIES

Forty-three mutant lines selected on the base of their high grain yield along with parent varieties Kuber, Zagorets, Asparuh, and Imeon were grown in field trials at the Institute of Agriculture – Karnobat in three consecutive years. Eight physical and chemical characteristics of grain related to the grain quality of malting barley were measured. There was considerable variation among barley mutant lines for all studied traits. Mutant lines with higher extract content, grain uniformity, 1000 grain weight, and lower protein content in grain compared to parent varieties were found. The correlations among traits showed that improvement of extract content of mutant lines was associated with increased grain uniformity, starch content, grain size, and 1000 grain weight and reduced protein content. The results from cluster analysis indicated that mutants originated from the same parent were grouped into different clusters. Therefore, the sodium azide treatment effectively induced diverse types of changes in the grain characteristics.</jats:p