Some effects of barley yellow dwarf virus on spring and winter cereals in glasshouse trials

The tolerance of spring and winter varieties of wheat, oats and barley to infection by barley yellow dwarf virus (BYDV) was examined in glasshouse tests. Severely affected plants were stunted and grain yields were considerably decreased because of decreases in both ear number and numbers and sizes of grains. Winter barley varieties were very susceptible and many were killed by BYDV infection. The winter wheat varieties were more widely tolerant than those of oats and barley. Individual seedling symptoms, although correlated with reductions in yield, could not be relied upon for accurate classification of all varieties in order of their susceptibility to infection. Symptoms of seedling infection incorporated into an index of infection permit estimates to be made o eventual decreases in yield by applying the formula DY = 1.4 × (SH+LA+LL)+18. Thus decrease in grain yield (DY) can be related to decreases in height (SH) and leaf length (LL) and increases in leaf area discoloured (LA) in seedling plants infected with BYDV.     

Interaction between barley yellow dwarf virus and rust in wheat, barley and oats, and the effects on grain yield and quality

In three separate experiments, the upper leaf surface of the fifth formed leaf of wheat cv. Highbury, the fourth and fifth leaves of barley cv. Julia and the third and fourth leaves of oat cv. Mostyn were inoculated in a spore settling tower with wheat brown rust (Puccinia recondita f. sp. tritici), barley brown rust (P. hordei) or oat crown rust (P. coronata f. sp. avenae), respectively. Fewer pustules developed on distal portions of leaves of plants infected with barley yellow dwarf virus (BYDV) than on similar portions of leaves from virus-free plants. There were no significant differences in the number of pustules on proximal leaf portions. In barley and oats, the number of pustules on distal leaf portions was negatively correlated with the amount of yellowing of the leaf areas scored. In wheat, symptoms of BYDV were mild and leaves were little affected by yellowing. The latent period of rust on wheat and oats was not affected by BYDV. In barley, BYDV reduced the latent period of rust on leaf 5, but not on leaf 4, and reduced it on proximal, but not distal, leaf portions. In other experiments, BYDV reduced the yield of wheat and oats by 44% and 66%, respectively, while BYDV-infected barley was almost sterile. The appropriate rust reduced the yield of wheat, barley and oats by 33%, 13% and 86%, respectively. When infected with both BYDV and rust, yield of wheat and oats was reduced by 63% and 91%, respectively. Neither BYDV nor rust affected the percentage crude protein content of wheat grain, nor did rust affect that of barley. In oats, BYDV and rust each significantly increased crude protein of grain, but rust infection of BYDV-infected plants tended to reduce it.     

Estimation of the chlorophyll content and yield of grain crops via their chlorophyll potential

The results of the assessment of the relationship between the chlorophyll content, crop yield and chlorophyll potential of crops of wheat, barley, and oat are presented. The results of a ground-based remotesensing technique and laboratory data were used to accomplish this assessment. The spectral reflectance data of agricultural crops obtained using a ground-based remote-sensing technique in the Krasnoyarsk region were used to calculate the chlorophyll potential. Long-standing experiments have been carried out in different seasons, under various lighting conditions. Spectral measurements were performed using a double-beam spectroradiometer, which was installed on a mobile work platform at a height from 5 to 18 m. A good correlation between the chlorophyll content, grain yield, and chlorophyll potential of different cultivars of wheat, barley, and oat has been shown. It was also shown that the values of chlorophyll potential are different for wheat, barley, and oat cultivars in the growing season.     

The invasion of root tips of cereals by the cereal cyst nematode Heterodera avenue

Newly germinated seedlings of susceptible cultivars of oats, wheat, barley and rye were inoculated with second-stage juveniles of Heterodera avenae in pots of sand. Subsequent examination showed oat root tips to be more commonly invaded, and by a greater range of nematode numbers than the other cereals. A comparison of oats and barley showed that lower nematode numbers in barley were not due to a higher emigration from barley; invasion, establishment and emigration by nematodes all being greater in oats. Second-stage juveniles were more likely to migrate prior to establishment in barley than in oats.     

Aspects in oat breeding: nutrition quality,nakedness and disease resistance,challenges and perspectives

Traditionally, the oat crop (Avena sativa) has been neglected in a number of respects, cultivated in cropping areas not optimal for wheat, barley or maize. In recent years the interest in oats has increased, particularly because of its dietary benefits and therapeutic potential for human health. The uniqueness and advantages of naked oats over other popular cereals, due to its potentially valuable nutritional composition, have been well studied and reported, opening new market “niches” for oats. Despite the well‐documented benefits, the status of the oat crop is still fragile, due to many reasons. The area cultivated for the oat crop is much less compared with other cereals, and therefore commercial efforts in oat breeding are less. Oat groat yield is lower than other cereals such as wheat and the nutritious uniqueness has not been reflected in agreeable market prices. The same price still exists for both naked and conventional/covered oats in the world grain market. The absence of visible market competitiveness, and some of the oat biological drawbacks, including low grain yield, keeps the oat crop as a lower profitability minor crop. This review is intended to analyse and summarise main achievements and challenges in oat genetics, agronomy and phytopathology to find possible ways of oat improvement and future perspectives for oat breeding.     

SOME OBSERVATIONS ON THE CEREAL-ROOT EELWORM POPULATION OF FIELD PLOTS OF CEREALS WITH DIFFERENT SOWING TIMES AND FERTILIZER TREATMENTS

In the autumn of 1953 an experiment was begun to follow changes in the cereal-root eelworm population of small plots on a field in Shropshire. The plots were cropped with either oats, wheat, barley or rye, sown in the autumn and spring, and some plots had fertilizer. Each plot received the same treatment for 3 years; in the fourth year an indicator crop of spring oats was grown on all the plots.
Under rye and autumn-sown wheat the eelworm population fell to a level which permitted a good oat crop in 1957. Autumn-sown wheat, barley and rye generally produced lower eelworm populations than their spring-sown counterparts, but autumn-sown oats proved to be the most efficient host. The order of host efficiency was oats (best), barley, wheat, rye. The eelworm populations were generally higher on plots receiving fertilizer treatment. In this experiment all oat plots, and spring-sown barley plus fertilizer, produced populations which severely damaged the 1957 oat crop.     

A COMPARATIVE STUDY OF THE GROWTH OF WILD OATS (AVENA FATUA L. AND A. LUDOVICIANA DUR.) AND OF CULTIVATED CEREALS WITH VARIED NITROGEN SUPPLY

Growth analysis of wild oats ( Avena fatua and A. ludoviciana ) grown in pots with different levels of nitrogen supply showed many similarities to spring barley, winter oats and winter wheat.
Small differences that could affect competition between wild oats and cereals occurred mainly in the seedlings. Wild oat seedlings were smaller than the corresponding cultivated cereals in total dry weight, total nitrogen content, leaf area and number of shoots. However, very young wild oat plants had higher net assimilation rates than the cultivated cereals and soon caught up and passed them. The difference in net assimilation rate did not persist, and in the later stages of growth differences in dry-matter production depended mainly on differences in leaf area. Another important difference between wild oats and cultivated cereals was that 98–100% of the wild oat seeds and none of the crop seeds were dormant 2 months after harvest.
Ear emergence in wild oats spread over a longer period, the range of ear heights was greater and the tallest ears were taller than in the corresponding cultivated cereals. Assimilation in the ear appeared to account for less of the total dry matter of the plants of wild and cultivated oats than of wheat. The wild oats produced more seeds per plant than the cultivated cereals, but the 1000-grain weight, and hence the total dry weight of seeds, was lower in the weeds than in the crop.
Addition of nitrogen to the soil affected the growth of the wild oats in the same ways as the cultivated cereals; they took up the same amount of nitrogen per plant as winter oats and winter wheat but more than spring barley.
It is concluded that wild oats are most susceptible in the seedling stage to competition from the crop and that nitrogenous fertilizer applied to an infested field is unlikely to alter the balance between the yields of crop and of wild oats.     

Grain yield and incidence of take-all (Ophiobolus graminis Sacc.) in wheat grown in different crop sequences

The yield of wheat and the incidence of take-all were measured in crops grown in six different 4-year sequences, repeated in 3 successive years. The first crop of winter wheat grown after oats or beans yielded 13–23 cwt/acre (1632–2887 kg/ha) more grain than wheat after wheat or barley. Spring wheat after oats yielded 2–5 cwt/acre (250–625 kg/ha) more than spring wheat after wheat. The smaller yields of wheat after wheat or barley were caused mostly by greater prevalence of take-all. Regression analysis indicates that each 1 % increase in straws with take-all decreased yield of winter wheat by 0·6%. Take-all was more prevalent in the second and third successive wheat crops after oats than in the fourth crop.     

Response of oat cultivars to <Emphasis Type="Italic">Fusarium</Emphasis> infection with a view to their suitability for food use

Oats as a source of antioxidants and complex polysaccharides are currently an important component in human nutrition. Producing healthy, safe and high-quality grain for this purpose depends upon growing oat cultivars with improved resistance to diseases caused by Fusarium spp. producing mycotoxins. Thirteen cultivars of naked (Ábel, Detvan, Izák and Avenuda) and covered (Zvolen, Auron, Atego, Flämingsstern, Kanton, Viktor, Zla?ák, Euro and Ardo) oats were inoculated with conidial suspensions of F. culmorum isolate in the field at flowering in 2006 and 2007. After harvest, reduction in thousand-kernel weight (R-TKW), reduction in panicle-kernel weight (R-PKW), and deoxynivalenol (DON) content in grain and hulls were determined. The ELISA immunochemical method was employed for the quantitative analyses of DON. Values of yield components (R-TKW; R-PKW) were 35.4% and 31.1% lower in dehulled covered oats than in naked oat cultivars. The DON accumulation was highest in hulls as compared with DON content in kernels of naked and covered oat cultivars. Accumulation of DON in dehulled covered cultivars was 34.4% lower than the average contamination in naked cultivars. When the cultivars were compared, there were positive correlations between R-TKW and R-PKW and also between DON content and R-PKW. With a view to growing oat cultivars for production of cereal foods, it was shown that dehulling of covered oat grain resulted in substantially reduced DON content.     

Liming and deep ripping responses for a range of field crops

Grain yields were measured over 2 seasons from a range of field crops following liming and deep ripping an acid and compacted soil in north-eastern Victoria. Lime (2.5 t ha^–1) substantially reduced the level of exchangeable Al and exchangeable Mn whilst raising soil pH by about 1.0 unit. The crops grown were 7 cultivars of wheat and one cultivar each of triticale, oats, barley, rapeseed, safflower, field pea, chick pea and lupins. With the exception of lupin, liming the soil increased (p=0.05) the grain yield of all crops and cultivars. With the wheat cultivars there were 2 distinct groups with different tolerance to soil acidity. Wheat, oats, triticale and lupins had higher absolute yields than the other crops. Safflower and chick pea had very low yields without soil amendment. The magnitude of the lime response did not differ between the wheat cultivars (17%) or between any of the crop species (range 9–29%). Deep ripping the soil to break a hard compacted layer resulted in more yield for all the cereals and safflower. The results demonstrate the importance of using crops with tolerance to acid soil conditions as well as gains that can be obtained with ameliorating identifiable soil problems.     

A Survey Investigating the Infection of Fusarium langsethiae and Production of HT‐2 and T‐2 Mycotoxins in UK Oat Fields

Fusarium langsethiae is a toxigenic fungal species that has been reported in European small‐grain cereal crops such as oats, wheat and barley. Although its relative contribution to fusarium head blight (FHB) symptoms is not well understood, it is reported to contaminate these cereals with high levels of HT‐2 and T‐2 trichothecenes mycotoxins that are currently under consideration for legislation by the European Commission. Ten commercial oat fields in Shropshire and Staffordshire (two adjacent counties in the Midlands) in the UK were surveyed in the 2006/2007 growing season. Samples were taken from predetermined field locations at Zadoks growth stages 32/33, 69, 77‐85 and 90‐92 for F. langsethiae biomass and HT‐2 and T‐2 toxins quantification. The results from this study showed that oats can be heavily infected with F. langsethiae and have high concentrations of HT‐2 and T‐2 toxins with no apparent FHB symptoms. The regression of HT‐2 + T‐2 toxins on F. langsethiae DNA concentration was highly significant (P < 0.001, r² = 0.55). The results indicated that although F. langsethiae had no direct effect on crop yield, it may result in indirect economic losses where the grain can be rejected or downgraded as a result of intolerable levels of HT‐2 and T‐2 toxins, which are of human food and animal feed safety concern. The influence of cultural field practices on the infection and HT‐2 and T‐2 toxins accumulation in oats was not clear and warrants further studies to identify the sources of F. langsethiae inoculum and conditions favourable for infection and mycotoxin production.     

Differences Between Barley, Oats and Wheat in the Occurrence of Deoxynivalenol and Other Trichothecenes in Norwegian Grain

The amount of the Fusarium toxins deoxynivalenol (DON). 3-acety-DON. ivalenol and fusarenon × have been determined in about 3000 samples of barley, oats and wheat grown in Norway. The samples were collected in the period 1988–1994. and grouped according to grain species, year of production, district and sample category. The DON content was found to be significantly higher in oats than both barley and wheat in grain produced by ordinary grain producers in Norway. Of samples collected from grain silos. 68.7% of the barley. 97.1% of the oats and 66.3% of the wheat samples were found to contain 30 mg/kg of DON or more. The proportion containing 1000 μg kg or more was 2.1.13.4and0.0% in burley, oats and wheat, respectively. However, these variations in contamination level were not reflected in the results from two field trials, where the grain species were grown side-by-side in the same fields. The differences in contamination level between the grain species seem to be due partly to edaphic and agrotechnical factors and partly to variation in the susceptibility to different Fusarium species in interaction with climatic factors. Nivalenol(≥ 50 μg/kg) was detected in 8.3% of the barley samples. 8.2% of the oats and 0.4% of the wheat samples. Samples collected at the grain silos were then not included.     

Control of subterranean clover red leaf virus in broad bean crops with aphicides

Apterous Rhopalosiphum padi on the first leaf of cereal plants, developed faster and were more fecund at seedling to stem extension of barley, at tillering to earing of oats and at stem extension and earing of wheat. Feeding site on a mature plant also affected the rate of development and fecundity of the aphids; the largest and most fecund developed on the stems of oat and wheat plants. The consequences of these variations in reproductive performance are discussed in relation to the population dynamics of R. padi and its possible pest status in Britain.     

基于生理指标与籽粒产量关系的小麦品种抗冻性分析

以20个冬小麦品种为材料进行盆栽试验,对其在低温胁迫条件下功能叶超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）活性,丙二醛（MDA）、可溶性蛋白、可溶性糖含量以及籽粒产量、千粒重和籽粒形态性状进行测定.结果表明：拔节初期麦苗经-4 ℃低温胁迫后,不同品种冬小麦籽粒形态性状和产量性状均发生变化,绝大多数小麦品种籽粒长宽比、圆度和不育小穗数均增加,籽粒等效直径和面积及千粒重和籽粒产量均下降.通径分析表明,拔节初期低温处理后,功能叶SOD活性和可溶性糖含量是影响籽粒产量的主导因素,其中SOD活性对籽粒产量的直接影响较大,直接通径系数为-0.578.以籽粒产量下降的百分数作为小麦抗冻性评价的标准,可将20个小麦品种划分为3类：强抗冻类型的济麦19、济麦20、良星99、山农1135、山农8355、泰山23、泰山9818、汶农6号和烟农21,弱抗冻类型的临麦2号、潍麦8号、烟农19和淄麦12号,而其余7个品种属中度抗冻类型.苗期综合评价值（D值）与籽粒产量下降的百分数之间呈显著负相关(r=-0.512*),说明小麦苗期抗冻性强有利于获得较高的籽粒产量.苗期是小麦抗冻性鉴别选择的重要时期.     

Uptake and Distribution of Stable Strontium in 26 Cultivars of Three Crop Species: Oats,Wheat, and Barley for Their Potential Use in Phytoremediation

The main objective of this study was to investigate the accumulation and distribution of strontium (Sr) in 26 cultivars of wheat (Triticum aestivum L.), husk oat (Avena sativa L) and naked oat (Avena nuda), and barley (Hordeum vulgare L.) for their potential use in phytoremediation.Sr levels had no effect on the accumulation of shoot biomass at tillering or at maturity. Mean shoot Sr concentration of naked oat and barley at tillering was significantly (P < 0.05) higher than that of wheat; Neimengkeyimai-1, a naked oat cultivar, had the highest Sr concentrations. At maturity, of four naked oat cultivars, Neimengkeyimai-1 had the highest Sr content at all measured Sr levels. Leaves had the highest Sr concentrations, followed by roots and straw, and then grain with the lowest. Mean enrichment coefficients from soil to shoots ranged from 0.521 to 1.343; the percentage of stable Sr removed from the soil to the shoots at harvest time was more than 1.4% after 120 days. Neimengkeyimai-1 could be used as a model for further research to find more effective cultivars; and naked oat plants could be selected for phytoremediation to clean up contaminated soil.     

Survival and duration of development of Oscinella spp. (Diptera: Chloropidae) on different Gramineae in the laboratory

The duration of development and survival of Oscinella frit, O. nitidissima and O. nigerrima at different growth stages of several plant species was investigated in the laboratory. The effect of the infestation on the growth of plants was also quantified. Survival of O. frit larvae was significantly lower (P < 0.01) on barley than on either oats or wheat, between which there was no significant difference. Survival was usually highest when plants were infested at the two-leaf stage and lowest when plants were infested at the five-leaf stage. The duration of development of both male and female O. frit was longer on barley than on either oats or wheat and generally increased when older plants were infested. The proportion of male flies was greatest when older plants were infested. Duration of development and survival of O. frit was similar on oats and Lolium multiflorum, but larvae did not survive on Dactylis glomerata. Of the other Oscinella species, O. nitidissima larvae did not survive on oats, wheat and barley and O. nigerrima larvae did not survive on either oats or barley. The main shoots of cereal plants infested at the two-, three- or four-leaf stages were rapidly killed by O. frit larvae whereas many of those infested at the five-leaf stage continued to grow slowly. In response to attack proportionately more tillers were produced by oat plants than by either wheat or barley plants. When cereals were infested with O. nigerrima larvae the central shoots were damaged, but most recovered and continued to grow. Damage symptoms were most obvious when cereals were infested at the two-leaf stage, oats being more severely affected than either wheat or barley.     

Influence of the Russian wheat aphid <Emphasis Type="Italic">Diuraphis noxia</Emphasis> (Kurdjumov) (Homoptera,Aphididae) on productive qualities of spring bread wheat and barley grown from the seeds from aphid-infested spikes

The aftereffects of the Russian wheat aphid (RWA) Diuraphis noxia on sowing and productive qualities of barley and spring bread wheat grain were assessed. Seeds of 4 cultivars of barley (Volgar, Povolzhsky 65, Kazak, and Povolzhsky 16) and 4 cultivars of spring wheat (Kinelskaya 59, Kinelskaya Otrada, Kinelskaya Niva, and Kinelskaya 2010) from spikes infested and uninfested with RWA in 2007 and in 2014 were sown in the subsequent years, using 0.5 m² experimental plots in four replications, at a seeding rate of 300 grains/m². The least significant difference (LSD_0.5) was used to compare the mean ± standard deviation (SD) values. The field germination rate of seeds from spring wheat spikes damaged by RWA was reduced by 15%. Of the components of grain yield, barley and spring wheat grown from seeds from the infested spikes showed a 23-31% smaller number of productive tillers before harvesting, a 16% smaller number of grains per spike, a 13-16% lower grain weight per spike, and a total yield loss of 33-42%. In hulless bread wheat RWA fed on the developing kernels inflicting greater damage, whereas the hulled barley seeds were practically not damaged. The mean yield loss of the barley and spring wheat spikes infested with RWA was 24-32% and 50-66%, respectively. Due to the greater tillering capacity and formation of secondary productive tillers in barley, about 52% of the productive barley tillers and 37-39% of spring wheat ones were infested with RWA, which resulted in a comparable yield loss (20-25% in barley and 19-23% in spring wheat). Resistance to RWA was higher in spring wheat and barley cultivars with a shorter vegetation period, looser spikes, and thinner culm walls. The length of productive tillers damaged by RWA was reduced by 21-28%, which determined a lower incidence of leaf diseases.     

Infection of cereals and grasses by isolates of Polymyxa graminis (Plasmodiophorales)

The host range of isolates of Polymyxa was tested in mono-fungal sand cultures. Fourteen isolates of P. graminis, obtained from barley, wheat, oats or Poa annua and from several different countries, all infected barley and all but one infected wheat. Rye was also a good host, whereas oats (nine cultivars), Lolium multiflorum and Poa pratensis became only slightly infected. Wheat cultivars differed in susceptibility, with Galahad much more resistant than Avalon. Several common weed and pasture grasses were not infected by the two isolates tested. A range of wild Hordeum spp. were mostly susceptible to P. graminis and/or barley mild mosaic virus, which it transmits. An isolate of P. betae, used for comparison, caused slight infection on oats but not on other cereals. The variation within and between species of Polymyxa needs more detailed investigation.     

Quantifying relationships between rooting traits and water uptake under drought in Mediterranean barley and durum wheat

In Mediterranean regions drought is the major factor limiting spring barley and durum wheat grain yields. This study aimed to compare spring barley and durum wheat root and shoot responses to drought and quantify relationships between root traits and water uptake under terminal drought.One spring barley（Hordeum vulgare L. cv. Rum） and two durum wheat Mediterranean cultivars（Triticum turgidum L. var durum cvs Hourani and Karim） were examined in soil‐column experiments under well watered and drought conditions. Root system architecture traits, water uptake, and plant growth were measured. Barley aerial biomass and grain yields were higher than for durum wheat cultivars in well watered conditions. Drought decreased grain yield more for barley（47%） than durum wheat（30%, Hourani）. Root‐to‐shoot dry matter ratio increased for durum wheat under drought but not for barley, and root weight increased for wheat in response todrought but decreased for barley. The critical root length density（RLD） and root volume density（RVD） for 90% available water capture for wheat were similar to（cv. Hourani） or lower than（cv. Karim） for barley depending on wheat cultivar. For both species, RVD accounted for a slightly higher proportion of phenotypic variation in water uptake under drought than RLD.     

Inheritance of nitrite reductase and regulation of nitrate reductase, nitrite reductase, and glutamine synthetase isozymes

Banding patterns of nitrate reductase (NR), nitrite reductase (NiR), and glutamine synthetase (GS) from leaves of diploid barley (Hordeum vulgare), tetraploid wheat (Triticum durum), hexaploid wheat (Triticum aestivum), and tetraploid wild oats (Avena barbata) were compared following starch gel electrophoresis. Two NR isozymes, which appeared to be under different regulatory control, were observed in each of the three species. The activity of the more slowly migrating nitrate reductase isozyme (NR1) was induced by NO3- in green seedlings and cycloheximide inhibited induction. However, the activity of the faster NR isozyme (NR2) was unaffected by addition of KNO3, and it was not affected by treatments of cycloheximide or chloramphenicol. Only a single isozyme of nitrite reductase was detected in surveys of three tetraploid and 18 hexaploid wheat, and 48 barley accessions; however, three isozymes associated with different ecotypes were detected in the wild oats. Inheritance patterns showed that two of the wild oat isozymes were governed by a single Mendelian locus with two codominant alleles; however, no variation was detected for the third isozyme. Treatment of excised barely and wild oat seedlings with cycloheximide and chloramphenicol showed that induction of NiR activity was greatly inhibited by cycloheximide, but only slightly by chloramphenicol. Only a single GS isozyme was detected in extracts of green leaves of wheat, barley, and wild oat seedlings. No electrophoretic variation was observed within or among any of these three species. Thus, this enzyme appears to be the most structurally conserved of the three enzymes.