Damage potential of grasshoppers (Orthoptera: Acrididae) on early growth stages of small-grains and canola under subarctic conditions

We characterized the type and extent of grasshopper injury to above- and below-ground plant parts for four crops [barley (Hordeum vulgare L.), oats (Avena sativa L.), wheat (Triticum aestivum L.), and canola (Brassica campestris L.)] commonly grown, or with potential to grow, in central Alaska. Cages were placed on 48 pots containing plants in second to third leaf stages and stocked with 0, 2, 4, and 6 first-instar Melanoplus sanguinipes F. pot(-1). Plants were harvested 22 d after planting. Stem growth of barley and oats was not affected except at the highest grasshopper treatment. In canola, stem biomass was reduced at the medium and high grasshopper treatments, when most of the leaves had been consumed. The highest grasshopper treatment reduced leaf area in barley and oats by approximately 55%, and caused a significant reduction in dry weight of leaves, stems, and roots (41-72%). Wheat and canola plants were smaller than barley and oats across all treatments and, at the highest grasshopper density, above-ground portions of wheat and canola were completely destroyed. Length and surface area of roots of barley and oats were reduced by 20-28% again at the highest grasshopper density, whereas the reduction for wheat and canola ranged from 50 to 90%. There was little or no difference among all grasshopper densities for C-N ratio in leaf and stem tissues of all crops. The results suggest that wheat and canola are more susceptible than barley and oats and that densities > or = 2 pot(-1) (approximately > or = 50 m(-2)) of even very small grasshoppers could cause significant damage in small-grain and oilseed crop production.     

Effectiveness of sulfuryl fluoride for control of different life stages of stored-product psocids (Psocoptera)

With the phase-out and impending ban of methyl bromide, sulfuryl fluoride is among the most promising alternative fumigant insecticides for control of stored-product insect pests. It has been evaluated for control of several stored-product insect pests, but there are few data available on its efficacy for control of stored-product psocids (Psocoptera). We evaluated sulfuryl fluoride for control of different life stages of the psocids Liposcelis paeta Pearman, L. entomophila (Enderlein), L. bostrychophila Badonnel, L. decolor Pearman, and Lepinotus reticulatus Enderlein (Trogiidae) in 48-hr trials at 27.5 degrees C. Adults and nymphs were susceptible to sulfuryl fluoride. Complete (100%) adult and nymphal mortality was recorded at concentrations between 4 and 8 g/m3, except for L. decolor for which all adults were only killed at 24 g/m3. Eggs were tolerant to sulfuryl fluoride. Complete egg mortality was achieved at 24 and 72 g/m3 for L. reticulatus and L. decolor, respectively. Survival of L. paeta eggs was recorded even after exposure to 96 g/m3. Given that the highest United States label concentration for sulfuryl fluoride for a 48-h exposure interval is 31.25 g/m3, our study indicates that high doses and/or longer exposures are needed for complete mortality of eggs of L. decolor and L. paeta. Moreover, the present work suggests that there is considerable variation in efficacy of sulfuryl fluoride for control of different psocid species.     

Bright Greenish-Yellow Fluorescence and Aflatoxin in Agricultural Commodities

The corn milling industry has widely accepted the presence of bright greenish-yellow fluorescence under a black light as a presumptive indicator of aflatoxin (a poison produced by the mold Aspergillus flavus). This test was applied to wheat, oats, barley, rice, coconut, white corn, yellow corn, peanuts, sorghum, and soybeans, and evaluated in the laboratory. Our study supported the use of bright greenish-yellow fluorescence as a presumptive test for aflatoxin in wheat, oats, barley, corn, and sorghum.     

Nonhost resistance of barley is successfully manifested against Magnaporthe grisea and a closely related Pennisetum-infecting lineage but is overcome by Magnaporthe oryzae

Magnaporthe oryzae is a major pathogen of rice (Oryza sativa L.) but is also able to infect other grasses, including barley (Hordeum vulgare L.). Here, we report a study using Magnaporthe isolates collected from other host plant species to evaluate their capacity to infect barley. A nonhost type of resistance was detected in barley against isolates derived from genera Pennisetum (fontaingrass) or Digitaria (crabgrass), but no resistance occurred in response to isolates from rice, genus Eleusine (goosegrass), wheat (Triticum aestivum L.), or maize (Zea mays L.), respectively. Restriction of pathogen growth in the nonhost interaction was investigated microscopically and compared with compatible interactions. Real-time polymerase chain reaction was used to quantify fungal biomass in both types of interaction. The phylogenetic relationship among the Magnaporthe isolates used in this study was investigated by inferring gene trees for fragments of three genes, actin, calmodulin, and beta-tubulin. Based on phylogenetic analysis, we could distinguish different species that were strictly correlated with the ability of the isolates to infect barley. We demonstrated that investigating specific host interaction phenotypes for a range of pathogen isolates can accurately highlight genetic diversity within a pathogen population.     

The involvement of wheat and common bean lectins in the control of cell division in the root apical meristems of various plant species

The effects of wheat germ agglutinin (WGA) and phytohemagglutinin (PHA) at the concentration of 1 mg/l on the rate of cell division in the root apical meristem of wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), rice (Oryza sativa L.), and common bean (Phaseolus vulgaris L.) seedlings were compared. WGA enhanced cell division in the roots of barley and rice approximately similarly as in wheat roots but did not affect division of meristematic cells in the roots of common bean seedlings. In contrast PGA enhanced mitotic activity in the root apical meristem of common bean seedlings but did not affect division in the wheat and barley roots. Seedling treatment with lectins shifted the hormonal balance in them toward accumulation of growth activators (IAA and cytokinins). The relationship between lectin and hormonal systems in the control of cell division is discussed.     

Occurrence of acid and neutral carboxypeptidases in germinating cereals

High neutral metallocarboxypeptidase activity (EC 3.4.17) has earlier been detected in young seedlings of rice ( Oryza sativa L.) using benzyloxycarbonyl-L-phenylalanyl-L-alanine (Z-Phe-Ala) as substrate at pH 7. This finding was confirmed, and it was observed that the activity could be assayed with higher specificity and sensitivity by using Z-Gly-Ala or Z-Gly-Phe as substrate at pH 6.5–7. No corresponding activity was detected in seedlings of barley ( Hordeum vulgare L. cv. Himalaya), oats ( Avena sativa L.) or maize ( Zea mays L.). The seedlings of the four cereals possessed similar activities of acid carboxypeptidases (EC 3.4.16; hydrolysis of Z-Phe-Ala and Z-Ala-Phe at pH 5.2 and of Z-Ala-Arg at pH 5.7). However, in endosperms of germinating rice and maize these activities were only about 1–5% of those in barley and oats. A corresponding, although less pronounced, difference was evident between the scutella of the two pairs of cereals. The possible relationship between neutral carboxypeptidase activity and ability to grow in anaerobic conditions is discussed.     

Future utilization of cereal crops

Estimates made on the uses for cereals (corn, wheat, oats, barley, sorghum, rice, and rye) in 1975 are based upon a number of assumptions. If those made in this article are approached, the pattern of cereal use will be much the same as it is at present.     

Cereal prolamin evolution and homology revealed by sequence analysis

Prolamin mixtures were isolated from oats, rice, normal and high-lysine sorghum, two varieties of pearl millet, two strains of teosinte, and gamma grass and subjected to NH₂-terminal amino acid sequence determinations. In each case (except for rice, whose prolamins apparently have blocked or unavailable NH₂-terminal residues), primarily a single sequence was observed despite significant heterogeneity, suggesting that prolamin homology in each cereal arose through duplication and mutation of a single ancestral gene. Comparisons were then made to prolamin sequences previously determined for wheat, corn, barley, and rye. Within genera, different varieties or subspecies exhibited few differences, but more distantly related genera, subtribes, and tribes showed increasingly large differences. Within the subfamily Festucoideae, no homology was apparent between prolamins of oats and those of the subtribe Triticinae (including wheat, rye, and barley, for which prolamin homology was previously demonstrated). Within the subfamily Panicoideae, corn was shown to be closely related to teosinte but more distantly to Tripsacum. Sorghum was shown to have diverged less from corn than had millet. These comparisons demonstrate that prolamin sequence analyses can successfully predict and clarify evolutionary relationships of cereals.     

Sequence analysis of the ribosomal internal transcribed spacers region in psocids (Psocoptera: Liposcelididae) for phylogenetic inference and species discrimination

Psocids (Psocoptera: Liposcelididae: Liposcelis spp.) are major pests of stored grain and commonly occur on a wide range of stored products. Increasingly, the genus of Liposcelis has gained recognition of their importance due to their feeding on stored grains, contaminating food, and agricultural commodities as well as transmitting harmful microorganisms, including fungi and bacteria. Psocids have close morphological similarities and often commix occur at the same ecosystems. Therefore, a first step necessary to further implement population studies is the accurate identification of species, based on molecular methods. In this study, we determined nucleotide sequences of the nuclear rDNA internal transcribed spacer (ITS)1-5.8S-ITS2 region in 100 individuals of six Liposcelis species (including Liposcelis bostrychophila Badonnel, Liposcelis entomophila (Enderlein), Liposcelis decolor (Pearman), Liposcelis tricolor Badonnel, Liposcelis paeta Pearman, and Liposcelis yunnaniensis Li & Li) from 16 locations of China. We evaluated the suitability of this marker for phylogenetic inference study in the Liposcelis species. We also developed a molecular identification method for six Liposcelis species based on ITS2 sequence. Results demonstrate that ITS1-5.8S-ITS2 sequences are a useful tool for the population genetic study and phylogeny estimation of Liposcelis species. The results of this study indicate that the ITS2 sequences can be a reliable tool for species discrimination of the six species of psocids tested here. In addition, the multiplex method described proved reliable when tested across different geographical populations.     

Use of Random Amplified Polymorphic DNA Analysis for Economically Important Food Crops

The objective of this review is to summarize numerous studies on the use of the random amplified polymorphic DNA （RAPD） technique on rice, corn, wheat, sorghum, barley, rye, and oats to examine its feasibility and validity for assessment of genetic variation, population genetics, mapping, linkage and marker assisted selection, phylogenetic analysis, and the detection of somaclonal variation. Also we discuss the advantages and limitations of RAPD. Molecular markers have entered the scene of genetic improvement in different fields of agricultural research. The simplicity of the RAPD technique made it ideal for genetic mapping, plant and animal breeding programs, and DNA fingerprinting, with particular utility in the field of population genetics.     

Willet M. Hays, great benefactor to plant breeding and the founder of our association

Willet M. Hays was a great benefactor to plant breeding and the founder of the American Genetic Association (AGA). We commemorate the AGA's centennial. We mined university archives, U.S. Department of Agriculture (USDA) yearbooks, plant breeding textbooks, scientific periodicals, and descendants for information. Willet Hays first recognized the individual plant as the unit of selection and started systematic pure-line selection and progeny tests in 1888. He developed useful plant breeding methods. He selected superior flax (Linum usitatissimum L.), wheat (Triticum vulgare L.), corn (Zea mays L.), barley (Hordeum vulgare L.), and oat (Avena sativa L.) varieties, and discovered Grimm alfalfa (Medicago sativa L.); all became commercially important. He initiated branch stations for better performance testing. Willet Hays befriended colleagues in other universities, in federal stations, in a London conference, and in Europe. He gathered and spread the scientific plant breeding gospel. He also improved rural roads and initiated animal breeding records and agricultural economics records. He started the AGA in 1903, serving as secretary for 10 years. He became assistant secretary of agriculture in 1904. He introduced the project system for agricultural research. He authored or coauthored the Nelson Amendment, the Smith-Lever Act, the Smith-Hughes Act, and the protocol leading to the United Nations Food and Agriculture Organization-all involved teaching agricultural practices that improved the world.     

Amino Acid and Peptide uptake in the scutella of germinating grains of barley, wheat, rice, and maize

Scutella separated from germinating grains of barley (Hordeum vulgare L.), wheat (Triticum aestivum L.), rice (Oryza sativa L.), and maize (Zea mays L.) took up the four amino acids and the three peptides tested from incubation media. The uptake of amino acids by wheat scutella was similar to that of barley scutella and was via at least four uptake systems: two nonspecific amino acid uptake systems, one system specific for proline, and another system specific for basic amino acids. The scutellum of rice apparently has two nonspecific systems and a system specific for the basic amino acids, but the proline-specific system is lacking. The scutellum of maize seems to have the same systems as the scutellum of rice, but one (or both) of the nonspecific systems differs from that of the other species studied in taking up arginine only slowly. No great differences were observed in the uptake of peptides in the four species studied. The rates of uptake of different amino acids and peptides were of the same order of magnitude in the four cereals. The fact that carboxypeptidase activities in the endosperms of wheat and barley are 20-to 100-fold higher than those in rice and maize, does thus not seem to be reflected in the uptake properties of the scutella.     

Amylolytic Activities in Cereal Seeds under Aerobic and Anaerobic Conditions

An adequate carbohydrate supply contributes to the survival of seeds under conditions of limited oxygen availability. The amount of soluble, readily fermentable carbohydrates in dry cereal seeds is usually very limited, with starch representing the main storage compound. Starch breakdown during the germination of cereal seeds is the result of the action of hydrolytic enzymes and only through the concerted action of [alpha]-amylase (EC 3.2.1.1), [beta]-amylase (EC 3.2.1.2), debranching enzyme (EC 3.2.1.41), and [alpha]-glucosidase (EC 3.2.1.20) can starch be hydrolyzed completely. We present here data concerning the complete set of starch-degrading enzymes in three cereals, rice (Oryza sativa L.), which is tolerant to anaerobiosis, and wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.), which are unable to germinate under anoxia. Among the cereal seeds tested under anoxia, only rice is able to degrade nonboiled, soluble starch, reflecting the ability to degrade the starch granules in vivo. This is explained by the presence of the complete set of enzymes needed to degrade starch completely either as the result of de novo synthesis ([alpha]-amylase, [beta]-amylase) or activation of preexisting, inactive forms of the enzyme (debranching enzyme, [alpha]-glucosidase). These enzymes are either absent or inactive in wheat and barley seeds kept under anaerobic conditions.     

Influence of paddy and corn in different rotations on wheat yield,nutrient removal and soil properties

Summary In a 3 year field study, the effect of two rotations, paddy (Oryza sativa L.), wheat (Triticum aestivum L.), mung (Phaseolus aureus L.) and corn (Zea mays L.), wheat (Triticum aestivum L.), mung (Phaseolus aureus L.) on wheat yield and chemical, physical and biological properties of soil was evaluated. Grain yield of the wheat sown after paddy during 1972–73, 1973–74 and 1974–75 was lesser by 0,300 and 390 kg/ha respectively than that of the wheat following corn. The reduction in the yield of wheat was attributed to relatively higher NPK removal by paddy, greater immobilization of N applied to wheat and deterioration of soil physical conditions in the paddy field. Total NPK removal by paddy average 131 kg/ha more than that by corn. Sharp increase in bacterial population of soil during early growth of wheat that followed paddy and the concurrent less available N in soil and low N content in wheat plants suggested that the N applied to wheat was immobilised to organic form. The increase in soil bulk density and particle dispersion ratio and decrease in water storage in deeper soil layers in the paddy field probably restricted the root proliferation and growth of wheat.     

杀虫剂胁迫下嗜卷书虱和嗜虫书虱能源物质的代谢比较

采用比色法测定嗜卷书虱（Liposcelis bostrychophila）和嗜虫书虱（L．entomophila）体内甘油三酯、多糖和可溶性蛋白的贮存量。结果表明,嗜虫书虱体内3种物质的贮存量均显著高于嗜卷书虱。在毒死蜱和丁硫克百威的胁迫下,嗜虫书虱体内3种物质的变化幅度均大于嗜卷书虱,其中甘油三酯的含量先增高后降低,整体呈现下口抛物线趋势;多糖和可溶性蛋白的消耗率增加。这些说明在毒死蜱和丁硫克百威的作用下,书虱更多地启动了多糖和可溶性蛋白的代谢,降低了对甘油三酯的利用,以应对杀虫剂的胁迫。     

Kinetics of direct fermentation of agricultural commodities to L(+) lactic acid byRhizopus oryzae

Summary The kinetics of fermenting barley, cassava, corn, oats, and rice directly to L(+) lactic acid byRhizopus oryzae NRRL 395 were determined. The rates of carbohydrate consumption and L(+) lactic acid production were found to be influenced by the type of substrate, the substrate concentration, the fermentation temperature, and the presence of a neutralizing agent.     

Inhibitors of animal cell-free protein synthesis from grains

We described earlier the purification and properties of a protein (tritin) from wheat that enzymatically inhibits translation in cell-free systems from animals but not plants. In this report, we have examined 11 additional grains (Family Gramineae) and three other seeds for the presence of tritin-like proteins. In addition to wheat species, barley, oats, rye, triticale and corn were found to be sources of inhibitor; no inhibitor could be detected in rice, millet, sesame, alfalfa, mung bean or common bean seeds. The inhibitors from barley and rye were purified and found to differ from tritin with respect to heat inactivation, although they are similar to tritin with respect to molecular weight, behavior during purification and specific activity. The inhibitor from corn was purified and found to differ from tritin with respect to heat inactivation and molecular weight, although it is similar to tritin in behavior during purification and specific activity. These inhibitors constitute 2–17% of the total extractable protein in these grain s. Thus, wheat, barley, rye and corn can serve as convenient sources of a family of closely related inhibitors of protein synthesis which, when conjugated with lectins, antibodies, or hormones, could prove useful as chimeric toxins.     

Seasonal abundance of aphids (Homoptera: Aphididae) in wheat and their role as barley yellow dwarf virus vectors in the South Carolina coastal plain

Aphid (Homoptera: Aphididae) seasonal flight activity and abundance in wheat, Triticum aestivum L., and the significance of aphid species as vectors of barley yellow dwarf virus were studied over a nine-year period in the South Carolina coastal plain. Four aphid species colonized wheat in a consistent seasonal pattern. Greenbug, Schizaphis graminum (Rondani), and rice root aphid, Rhopalosiphum rufiabdominalis (Sasaki), colonized seedlingwheat immediately after crop emergence, with apterous colonies usually peaking in December or January and then declining for the remainder of the season. These two aphid species are unlikely to cause economic loss on wheat in South Carolina, thus crop managers should not have to sample for the subterranean R. rufiabdominalis colonies. Bird cherry-oat aphid, Rhopalosiphum padi (L.), was the second most abundant species and the most economically important. Rhopalosiphum padi colonies usually remained below 10/row-meter until peaking in February or March. Barley yellow dwarf incidence and wheat yield loss were significantly correlated with R. padi peak abundance and aphid-day accumulation on the crop. Based on transmission assays, R. padi was primarily responsible for vectoring the predominant virus serotype (PAV) we found in wheat. Pest management efforts should focus on sampling for and suppressing this aphid species. December planting reduced aphid-day accumulation and barley yellow dwarf incidence, but delayed planting is not a practical management option. English grain aphid, Sitobion avenae (F.), was the last species to colonize wheat each season, and the most abundant. Sitobion avenae was responsible for late-season virus transmission and caused direct yield loss by feeding on heads and flag leaves during an outbreak year.     

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.     

Reproduction and feeding behavior of Myzus persicae on four cereals

Green peach aphid, Myzus persicae (Sulzer), does not overwinter outdoors in Minnesota; it arrives each spring on low-level jet streams from the south. After arrival, anholocylic reproduction occurs on numerous herbaceous species, including many common weeds, before movement to potato, Solanum tuberosum L. In investigating aphid feeding behavior on barrier crops, we observed winter wheat, Triticum aestivum L., colonized by green peach aphid. The Northern Great Plains grows 94,000 ha of potatoes and 20.5 million ha of small grain cereals each year, the latter potentially providing an early emerging and widely distributed green peach aphid host to influence early season potato colonization. Life tables statistics indicated green peach aphid had its highest reproductive potential among cereals on winter wheat, with rye (Secale cereale L.) > barley (Hordeum vulgare L.) > oats (Avena sativa L.). Green peach aphid was found to colonize barley, rye, and winter wheat, but not oats. Mean generation time, net reproductive rate, doubling time, and finite rate of increase were significantly different between host plants. Electrical penetration graph technique indicated mean nonpenetration duration by green peach aphid was significantly different among plant species, and significantly longer on winter wheat than on the other cereals. Mean xylem phase duration was not significantly different among plant species but sieve element salivation was of longest duration on potato. Phloem sap ingestion (E2) was also significantly different among plant species with longest E2 duration on winter wheat. This study demonstrates that this aphid can effectively use key cereals at the vegetative stage.