Investigating the susceptibility and resistance barley ( Hordeum vulgare L.) cultivars against the Russian wheat aphid (Diuraphis noxia)

Six hulless barley (Hordeum Vulgare L.) cultivar, including 3 normal, 2 waxy, and 1 colored-waxy, was used to substitute 20% of wheat flour for pan-bread making. Replacing 20% barley flour significantly increased β-glucan content, which ranged in 0.98-1.36% for normal, 1.65-1.67% for waxy, and 1.50% for colored-waxy barley, which are all higher than wheat flour (0.14%). Pasting viscosity of barley flour blends varied by barley type and cultivar, presenting that barley cv. Dapung (DP) had the highest peak viscosity of 170.1 RVU, whereas the lowest value was 80.2 RVU in “Jasujeongchal (JSJC)”. Substitution of barley flour decreased the Hm and H’m value during dough fermentation and estimated a reduction of bread qualities compared to wheat bread. Bread loaf volume varied by barley type and cultivar, showing a slight decrease in loaf volume, but increase in crumb firmness compared to wheat bread. Among barley cultivars, DP barley showed high bread loaf volume (691.7 cm3 /g) with lower firmness (11.8 N). In contrast, bread made from JSJC barley flour had the lowest bread-making qualities probably due to bran layer inclusion. It appeared that barley type influenced more than barley cultivars although the mean values of all quality parameters slightly varied by barley cultivar. Results indicated that the inclusion of barley flour for bread-making could provide an elevated intake of β-glucan, which had health benefits by increasing dietary fiber content.

Bipolaris sorokiniana is the causal agent of spot blotch and other diseases in barley and wheat in different parts of the world. This study investigated the reaction of nine barley cultivars and four wheat cultivars to infection by 11 B. sorokiniana isolates. All B. sorokiniana isolates produced necrotic lesions on the inoculated barley and wheat cultivars, with no significant differences among most isolates in the necrotic lesion size. However, B. sorokiniana isolates induced significantly varying levels of chlorotic lesions and spores eight days following inoculation (P 7 mm) and produced thousands of conidia per cm2 of leaf area. A significant and positive correlation was found between the number of conidia produced on leaves and the size of the chlorotic lesions (P < 0.05), which suggests that the chlorotic weakened tissues provide a favorable site for spore production. Screening cultivars for resistance to spot blotch disease showed that barley cultivars ’Omani’ and ‘Beecher’ and wheat cultivars ’Cooley’ and ‘K65’ were the least susceptible to B. sorokiniana. The study shows the lack of host specialization of B. sorokiniana on wheat and barley. The apparently resistant barley and wheat cultivars should be used in future breeding programs for resistance to spot blotch.

ABSTRACTRussian wheat aphid [RWA; Diuraphis noxia (Mordvilko)] is a worldwide insect pest of barley (Hordeum vulgare L.), causing crop losses each year. Previously identified resistant barley lines do not show variable reactions to the eight United States RWA biotypes identified by wheat reactions. However, additional RWA isolates have been identified outside the United States. The objective of this research was to determine whether additional RWA biotypes that impact resistance in barley exist and whether resistance to these biotypes is present in the resistant barley germplasm and cultivars that have been developed by the USDA‐ARS. A total of 166 barley lines were rated for chlorosis and leaf rolling in response to infestation with RWA United States’ biotype 1 and to individual isolates from Hungary, Chile, Mexico, and Iran. Each barley line was genotyped for 5912 single nucleotide polymorphism (SNP) markers, and the combined data were used for association mapping of loci associated with resistance to each RWA isolate. A total of 40 loci were associated with resistance to the five RWA isolates. Biotype differences were evident, with only 23 lines showing resistance to all five biotypes. Loci with large effects on mean chlorosis and rolling differences were found for resistance to biotypes from the United States, Hungary, and Chile, while the loci for resistance to biotypes from Mexico and Iran had small effects on these traits, which may pose problems for developing resistant germplasm. The 23 lines resistant to all biotypes included 10 unadapted germplasm accessions and 13 improved germplasm lines and provide useful germplasm for developing new barley cultivars with resistance to multiple RWA biotypes.

Phenolic linked anti-hyperglycemic bioactives of barley (Hordeum vulgare L.) cultivars as nutraceuticals targeting type 2 diabetes

ABSTRACTRussian wheat aphid (RWA) [Diuraphis noxia (Mordvilko)] is an increasing problem on barley (Hordeum vulgare L.) throughout the world. Genetic resistance has been identified and used to create barley germplasm and cultivars adapted to the United States. Several mapping studies have been conducted to identify loci associated with resistance, but questions remain, particularly regarding the extent of genetic diversity among resistance sources and improved lines and cultivars. Association analysis of resistant (R) and moderately resistant (MR), unadapted accessions held in the USDA–ARS National Small Grains Germplasm Collection, adapted germplasm lines derived from these accessions, and susceptible (S) elite cultivars was conducted using 4509 single nucleotide polymorphisms (SNPs) to identify markers linked to resistance. Resistance was associated with loci on chromosomes 1H, 2H, 3H, 5H, and 7H at p‐values &lt;0.0001, and the major 1H and 3H loci identified in previous tests were confirmed. However, the genetics of RWA resistance was shown to be complex, and it is likely that loci involved in resistance in some lines were not identified. Nevertheless, this analysis identified diversity among R lines and showed that most of the released RWA‐resistant cultivars had similar genotypes at loci associated with resistance. This analysis also identified R lines that were genetically dissimilar to the released cultivars at these loci. This information can guide parental selection for future breeding efforts designed to capture and deploy greater diversity for RWA resistance among new barley cultivars.

Phytase activity, phosphorus and phytate contents in hydroponic fodder (up to 12 days of grain germination) of four Tunisian barley (Hordeum vulgare L.) cultivars (Arbi, Ardhaoui, Souihli, and Rihane) were studied. Barley cultivars differed significantly in their phytase activity (0.6–1.6 U/g), phosphorus (3.2–5.0 mg/g DM) and phytate (4.2–4.7 mg/g DM) contents. Phytase increased significantly up to 8 days of germination and decreased steadily thereafter. The phytase activity after 8 days of germination was increased up to tenfold in Arbi and Ardhaoui cultivars, eightfold in Souihli and fivefold in Rihane. The increase in phytase activity during germination was accompanied by a significant decrease in phytate content for all barley cultivars (reduced by 92–97%). The decrease in phytate content of sprouted barley by germination should improve phosphorus availability of the grain. Based on their phytase activity and phosphorus contents before germination, barley cultivars are ranked as Rihane > Ardhaoui > Souihli > Arbi. However, after germinating for 12 days the differences among varieties in phytase activity, phytate and phosphorus contents became non-significant. Further research is warranted to highlight the effect of germination on other nutritional attributes of hydroponic sprouted barley and its suitability as a feedstuff for farm animals.

Differential responses of two Egyptian barley (Hordeum vulgare L.) cultivars to salt stress

Competitive interactions of fifty barley cultivars with Avena sterilis and Asperugo procumbens

The production and utilization of root-derived C is fundamental to the functioning of ecosystems. The objectives of this experiment were to quantify the amount of root-released C produced by two barley (Hordeum vulgare L.) cultivars, to evaluate the direct and indirect effects of shoot C, root C and root length on the root-released C and to quantify the kinetics of the decomposition of root-released C in soil for two barley cultivars. Seedlings of two barley cultivars, Abee and Samson, were cultured in nutrient solution for 20 d and then pulse-labelled with 14C for 5 d. Samson released more C than Abee during the entire experimental period. Root length had the greatest direct effect on root-released C for the two barley cultivars. Kinetics analysis of the decomposition of root-released C added to soil showed that the labile components of the added material was 87.3% for Abee and 74.4% for Samson with half-lives of 4.3 d and 4.5 d, respectively. The half-lives of the resistant components of the root-released C added to soil and microbially-derived material were 37.7 d for Abee and 29.6 d for Samson, respectively. The amount of root-released C and its decomposition rate in soil varied with cultivars used. Key words: Root-released C, path analysis, direct effect, indirect effect, 14C, decomposition, Typic Cryoboroll

Effect of Feeding Corn, Hull-Less or Hulled Barley on Fermentation by Mixed Cultures of Ruminal Microorganisms

ABSTRACTIn this work, the time-dependent effect of exogenous salicylic acid (SA) applied before cold stress was investigated on the regulation of antioxidative respond mechanisms in two barley (Hordeum vulgare L.) cultivars (Akhisar and Tokak) differed in cold tolerance. SA (0.1 mM) was applied to 7-days old barley seedlings growing under control conditions (20/18°C). After this application, the seedlings were transferred to cold conditions (7/5°C) at different times (7, 14, 21 and 28 days) for 3 days. Then, the contents of malondialdehyde (MDA), hydrogen peroxide (H2O2) and the activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX) were determined in the leaves (control, cold and SA + cold) from the seedlings harvested at 10, 17, 24 and 31 days. Moreover, the effect of cold stress was evaluated on the endogenous SA level at the both cultivars by comparing to control plants. The MDA content increased in the cold treatment while it decreased in the SA treatment at all the days studied at the both cultivars. The SA + cold treatment could have a variable effect on H2O2 content at the tolerant barley (Tokak) while decreased its content at the sensitive cultivar (Akhisar). The SA + cold treatment could increase the activities of POX and SOD at both cultivars, but it increased the CAT activity at the tolerant cultivar while decreased at the sensitive cultivar. In addition, the content of endogenous SA was decreased by cold stress at all the days studied at the barley cultivars as compared to control plants. The results show that the SA treatment could be effective on the regulation of the parameters studied at cold conditions until 31 days after SA application, and the importance of exogenous SA treatment before cold stress. It was concluded that exogenous and endogenous SA could play an ameliorating role on cold tolerance by regulating reactive oxygen species and the activities of antioxidative enzymes in both cold-sensitive and cold-tolerant cultivars of barley.

Salinity stress affects plant growth and development and underlying metabolisms. To mitigate the effects of the stress, plants responded by changing their physiological and biochemical activities and withstand the stress. The present study aimed to determine barley's (Hordeum vulgare L.) physiological and biochemical response to salinity stress conditions for 7 days and 14 days. Six barley cultivars (Alfa93, DWRB73, DL88, NB1, NB3, NDB1173) were grown under controlled conditions, and different level of salinity stress was applied. In addition, seedling growth, physiological and biochemical parameters, plant leaves RWC, and electrolyte leakage were analyzed. The overall seedling growth, RWC, and electrolyte leakage in salt susceptible lines Alfa93 and DWRB73 were low than the salt-tolerant barley lines (DL88, NB1, NB3, and NDB1173). Electrolyte leakage was 26.0 and 20.6% in Alfa93 and DWRB73, whereas it was 17.6, 14.6, 15.3, and 10.4% in DL88, NB1, NB3, and NDB1173, respectively at 300 mM salinity stress. The loss of photosynthetic pigments under salt stress was high in susceptible lines, salinity treated (300 mM NaCl) Alfa93 plants exhibit 49.5% and 59.5% of Chl-a than control plants after 7 and 14 days of treatment, respectively. However, at 300 mM stress level, NB1 (ST) showed less Chl-a loss after 7 days, whereas NDB1173 showed less reduction in Chl-a after 14 days. Antioxidant enzymes such as SOD, POX, CAT, and APX activities in susceptible line Alfa93 and DWRB73 were lower than tolerant lines. PCA analysis demonstrated a positive correlation between antioxidant enzyme activities and genotypes under salinity stress. PCA analysis described DL88 as the most tolerant, and DWRB73 was the most salt susceptible genotype among the studied barley genotypes. The present findings suggest that barley cultivars' physiological and biochemical activities under salinity stress conditions may be used to screen salt-tolerant crops.

The effects of extracted and purified anthocyanin (ACY) from mature berries of Vaccinium myrtillus L., on growth parameters, antioxidant enzymes, total phenolic (TP) content, total flavonoid (TF) content, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity were investigated in the roots of barley (Hordeum vulgare L.) cultivars Akhisar-98 and Erginel-90 under ionizing irradiation (IR; 10 Gy). The responses to IR and ACY-rich extract treatment in the two cultivars differed; Akhisar-98 was more radiosensitive than Erginel-90 in terms of root development, but IR-induced decreases in Akhisar-98 root length were alleviated by ACY-rich extract (100 µM). Peroxidase (POD) activity in Akhisar and Erginel cultivars decreased, while superoxide dismutase (SOD), glutathione reductase (GR), and ascorbate peroxidase (APX) activities increased. The ACY-rich extract increased POD activity, and decreased SOD, GR, and APX activities in the two barley cultivars. Although TP content increased in the Erginel cultivar more than the Akhisar cultivar, TF contents did not differ between the control and irradiated roots of the Erginel cultivar. Since TP content, TF content, and DPPH radical scavenging activity increased and H2O2 content decreased after ACY-rich extract treatment, ACY-rich extract treatment enhanced antioxidant activity, especially in the Akhisar cultivar. Treatment with ACY-rich extract conferred a greater tolerance to IR stress, especially after irradiation, in the two barley cultivars exposed to IR and exogenic ACY-rich extract. These findings indicate that the Erginel cultivar is more IR-tolerant than the Akhisar cultivar and that exogenous ACY-rich extract treatment promotes antioxidant capacity in barley cultivars under IR stress.

Heterodera avenae is a cereal cyst nematode that reduces wheat yields in the Pacific Northwest of the United States. Barley is also susceptible but there were no previous reports of resistance or tolerance to H. avenae in the United States. Spring barley cultivars were assayed in H. avenae-infested fields over 2 years. Cultivars were planted in plots treated or not treated with aldicarb. Forty-five cultivars were evaluated for the market classes of two- and six-row feed barley cultivars and two- and six-row malt barley cultivars. One two-row feed barley ('Lenetah') was ranked as resistant and four were tolerant or very tolerant. In total, 1 two-row malt barley ('Odyssey') was very resistant and 10 were tolerant or very tolerant. Two six-row feed and two six-row malt barley cultivars were tolerant or very tolerant but none were resistant. Seven feed barley cultivars were ranked as having a balance of at least moderate resistance plus moderate tolerance: 'Champion', Lenetah, 'Xena', 'Idagold II', 'Transit', 'Millennium', and 'Goldeneye'. This is the first report of resistance and tolerance of barley in H. avenae-infested fields in the Pacific Northwest. Barley productivity can be improved by planting resistant plus tolerant cultivars or by using highly resistant and highly tolerant cultivars as parents in barley improvement programs.

Genetic variability of seven Egyptian barley cultivars was analyzed utilizing sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) and random amplified polymorphic DNA (RAPD) techniques. The results of SDS-PAGE produced 12 bands ranging from 135 to 11 KDa. Two polymorphic bands at molecular weight (MW) 13 and 12 KDs were detected with 16.6% polymorphism among barely cultivars. In the other hand, five RAPD primers were employed to assess the genetic diversity and relationships between the seven Egyptian barley cultivars. RAPD analysis exhibited 93 amplicons (86% polymorphism) with an average number of 18.6 amplicons per primer. Genetic similarity of RAPD and protein input ranged from 0.31 to 0.83. The dendrogram of combined data had clustered all the cultivars into two main clusters; the first one containing all barley cultivars except Giza 123 cultivar which formed a separate cluster indicating that the genetic background of this cultivar was distinct from all cultivars. The results obtained from RAPD and protein analysis exhibit different level of polymorphism. RAPD profile is more suitable technique than SDS-PAGE in assessing genetic variation among the seven barely cultivars. Moreover, the present results suggest that, the increasing number of primers and using more different markers could be more accurate to discriminate the genetic variance between barley cultivars. Subsequently, this could be useful to differentiate between barley cultivars in the breeding program.