Green Wheat Research Articles

Photosynthesis, Ribulose-1,5-bisphosphate Carboxylase, Electron Transport, and Ribulose 1,5-Bisphosphate of Virescent and Normal Green Wheat Leaves

CO(2) gas exchange, ribulose-1,5-bisphosphate, and electron transport have been measured in leaves of a yellow-green mutant of wheat (Triticum durum var Cappelli) and its wild type strain grown in the field. All these parameters, expressed on leaf area basis, were similar in both genotypes except electron transport which was more than double in the wild type. These results, treated according to a recent photosynthesis model for C(3) plants, seem to indicate that the electron transport rate of mutant leaves is not sufficient to support the carboxylation derived through both the assimilation rate and the in vitro ribulose-1,5-bisphosphate carboxylase activity. It is suggested that under our experimental conditions photosynthetic electron transport is not the sole energy-dependent determinant of ribulose-1,5-bisphosphate regeneration in the mutant.

CONTROL OF GREEN FOXTAIL IN CEREALS WITH AC 206,784, ALONE AND IN MIXTURES WITH TRIALLATE FOR WILD OATS

Control of green foxtail (Setaria viridis (L.) Beauv.) with AC 206,784 (2-chloro-N-isopropyl-2′,3′-acetoxylidide) was evaluated at four locations in western Canada. With soil applications, control was good at Lacombe in 1978 but poor at Lacombe and Regina during 1979. Control was good at Brandon and Scott in 1979. At two locations in 1979, soil surface (PE) applications were less effective for control of green foxtail than preplant-incorporated (PPI) treatments. PPI treatments to a depth of 5 cm were more effective than PPI to 10 cm. Soil applications of AC 206,784 did not control wild oats (Avena fatua L.) or injure wheat (Triticum aestivum L.) under field conditions but did provide suppression of these species under greenhouse conditions. Barley (Hordeum vulgare L.) tolerance to AC 206,784 was good. Treating the soil zone containing the emerging coleoptiles of green foxtail and wheat caused more injury that treating the root zone. Application of AC 206,784 as a tank-mixture with triallate did not affect its activity on green foxtail or influence triallate activity on wild oats. In field and greenhouse experiments, control of green foxtail with AC 206,784 applied at the two-leaf stage was variable; at the four-leaf stage it was poor.

High resolution two-dimensional electrophoresis of protein from congenic wheat lines differing by single resistance genes

Two methods were developed for the extraction of proteins from green wheat leaves. The methods result in distinct, highly reproducible patterns of polypeptides when separated by two-dimensional electrophoresis. Interference due to phenolic compounds and proteinases was minimized by these methods, and over 300 polypeptides were observed when visualized with Coomassie blue stain. Comparisons of 12 different congenic host lines, each differing by a single gene for resistance to Erysiphe graminis f. sp. tritici ( Pm isolines), failed to reveal any differences in polypeptide mobility which could be attributed to, or associated with, a gene for resistance. Some seedlings of “Chancellor” wheat, the common background parent cultivar from which all of the Pm lines were derived, exhibited a unique polypeptide variant. The variant polypeptide was not found in all seedlings of “Chancellor”, nor was it found in any of the Pm lines tested. The variant polypeptide appears to reflect a change in molecular weight from about 63 000 to about 68 000, with a very slight change in charge (pI of about 4). The variant polypeptide is among the 300 most visible polypeptides in seedling extracts that were subjected to electrophoresis and stained with silver. Thus, the variant polypeptide appears to be made in a large number of copies. Chancellor appears to be a mixture of the original type and a variant type which appeared subsequent to the breeding of the Pm lines.

Dispersal of Alate Biotype C Greenbugs in Kansas12

Alate greenbugs were trapped at Hays, Kans., from 1974 to 1979, inclusive. There were two distinct flight periods each year. The first flight peaked during the first week of June, and the second during the last week of July (1974 to 1977) or the third week of August (1978 and 1979). Flight patterns indicated that early planting of both wheat and sorghum should be avoided. More greenbugs were trapped from SE than NW during the spring but not during the summer. More greenbugs were collected from heights of 3 to 6 m than from 1.5 m, but that might be attributed to type of ground cover. As the green vegetation increased, the numbers of greenbugs collected decreased; however, strips of green wheat did not provide practical protection to adjacent bordering areas.

Control of scarabaeid larvae of sweet potato by applying green wheat and MPP

Control of scarabaeid larvae of sweet potato by applying green wheat and MPP

Crop Identification in a Parkland Environment Using Aerial Photography

SUMMARYThe estimation of crop production using remote sensing techniques first requires a correct identification of the crops found in a given area. In Western Canada, the identification of field crops is hampered by the occurrence of confusion crops such as spring grains. These follow crop calendars and/or possess spectral signatures similar to each other. The results of an interpretation test using color and color infra-red photography show a higher percent correct identification of spring grains with the color photography. This is attributed in part to the differences in visible colors often noted in the field during the vegetative period between darker green wheat crops and lighter green oat and barley crops. A higher percent correct identification of fallow fields was attained with the color infra-red photography. Relatively high percent commission errors were made for grain and hay crops with both types of photography.

Proteolytic enzymes in green wheat leaves IV. Degradation of ribulose 1,5-bisphosphate carboxylase by acid proteinases isolated on DEAE-cellulose

Proteolytic enzymes in green wheat leaves IV. Degradation of ribulose 1,5-bisphosphate carboxylase by acid proteinases isolated on DEAE-cellulose

Proteolytic enzymes in green wheat leaves II. Purification by affinity chromatography, and some properties of proteinases with acid pH optima

A comparison of haemoglobin, 2,4-dinitrophenyl and N,O-dibenzyloxycarbonyltyrosine as ligands for the affinity chromatography of wheat-leaf proteinases delete widi acid pH optima, established that haemoglobin was the most satisfactory. Using haemoglo-bin-Sepharose 4B affinity chromatography it was possible to purify wheat-leaf acid proteinases, previously isolated on DEAE-cellulose, to homogeneity as judged by polyacrylamide gel electrophoresis. Some properties of three purified proteinases are presented and discussed.

Proteolytic enzymes in green wheat leaves I. Isolation on DEAE-cellulose of several proteinases with acid pH optima1

Proteolytic enzymes in green wheat leaves I. Isolation on DEAE-cellulose of several proteinases with acid pH optima1

Environmental factors limiting growth of Sporobolomyces roseus, an antagonist of Cochliobolus sativus, on wheat leaves

Sporobolomyces roseus Kluyver et Van Niel developed on green wheat leaves equally well in simulated dew as under conditions of high ambient relative humidity. Relative humidities varying from 65–95% had differential effects on the Sporobolomyces population. At 65% r.h. the population decreased but resumed growth when exposed to 95% r.h. Under optimum humidity the population reached a steady state at densities between 5 × 10 3 and 10 4 cells/cm 2 . Spraying leaves with nutrients resulted in additional growth of the population, reaching a steady state again within 10 days, at a density of ca . 5 × 10 5 cells/cm 2 . Nutrients were equally available under dew as under high r.h. Sporobolomyces could only profit from the nutrients if exposed to relative humidities of at least 90% during part of the day. Susceptibility to low r.h. and the ability to consume exogenous nutrients were similar in populations of individual cells and established colonies. A temperature of 32 °C during part of the day interfered with the growth rate but was not as detrimental as earlier field observations suggested. A S. roseus population stimulated to an antagonistic level by exogenous nutrients reduced infection of wheat leaves by Cochliobolus sativus (Ito & Kuribayashi) Drechsler ex Dastur to ca . 15%.

Influence of Temperature on Sterol Biosynthesis in Triticum aestivum

Sitosterol, campesterol, stigmasterol, and cholesterol were isolated from green wheat (Triticium aestivum var. Monon) seedlings. Sitosterol was the predominant sterol extracted from the shoot, root, and crown tissue. Cholesterol accounted for less that 1% of sterol in shoot tissue with only trace amounts in the root. A temperature change from 10 to 1 C resulted in a general decrease in sitosterol, stigmasterol, and campesterol in the shoot tissue. The cholesterol level was not altered significantly by the temperature change. The sterols in the root responded in a manner very different from those in the shoots. With the reduction in temperature, sterols first decreased and then recovered over a period of 7 to 14 days to levels that were equal to or exceeded the original levels. From these experiments, it would appear that root tissue can acclimate to the lower temperatures and continue sterol synthesis at the normal rate. The level and response of sterols in the crown tissue were intermediate between the root and shoot tissue. At 10 C the crown response was similar to that of root tissue, whereas, at 1 C the response more closely resembled that of the shoot.

The Oversummering and Dispersal of Inoculum of Puccinia striiformis in Oregon

Stripe rust (Puccinia striiformis) was found on grasses Urediospores were trapped on rod spore samplers in wheat-growing regions and in adjacent mountains of exposed in the field only after stripe rust was Oregon during late spring only after the disease was well well established on the wheat crop. The number of spores established on the wheat crop. Disease incidence on these trapped followed closely the development of the disease grasses diminished during summer, and approached zero in wheat fields near the traps. Throughout northeastern during August. Stripe rust was seen less frequently on Oregon, urediospores moved predominantly from west to grasses in the mountains than on grasses in the wheatland. east. Most plants of susceptible grass species were free from The results suggest that urediospores which infect the stripe rust in the field, but became infected when fall wheat crop come from rust that oversummers on inoculated in the greenhouse. Commercial wheat plantings residual green wheat and grasses within the wheatland. served as the sources of inoculum for natural infections of wheat in plots located up to 64 km from wheat fields. Phytopathology 63:13-17 The source of stripe rust (Puccinia striiformis established wheat plots in the mountains at various West.) inoculum for fall infection of Oregon's wheat distances from wheatland (Fig. 1). Ten wheat crop has remained undetermined since the discovery cultivars, differing in their susceptibility to stripe of the disease there in 1916 (4). The fungus has no rust, were grown at each site (Table 2). Nearly all the known alternate host, so urediospores must serve as wheat grown commercially in northeastern Oregon primary inoculum. The critical period in the disease during this study were the cultivars Gaines, Moro, and cycle is the period between ripening of the wheat Omar. Druchamp was also grown in the Willamette crop in July and the emergence of the new crop in Valley. October (12). During this interval, there is very little Two plots consisting of a 2-m row of each cultivar green wheat in Oregon because of the dry summers, were established at each location in the fall. Poultry We occasionally found stripe rust on ripening wheat wire cages (2 m X 6 m X 1.5 m), with rodent shields and residual green wheat during July and early August (12). The earliest when stripe rust was found on the fall-sown crop was in December, and then only Wheot-.Growing Area in early-sown fields. Since apparently little stripe rust oversummers on wheat in Oregon, we conducted investigations to determine whether rust oversummers on hosts other than wheat or whether inoculum moves in from some distant source. MATERIALS AND METHODS.-Wheat in northeastern Oregon is grown in three areas separated • ... by mountains (Fig. 1). These are the Columbia Basin, . rx i .;:a _:i. ! .. consisting of Wasco, Sherman, Gilliam, Morrow, and -.. ,.•I .: Umatilla Counties; the grande Ronde Valley of '.o, . .. I, L-_, '..-I adjacent mountains. Observations were also made in ) ii' . .iI the Cascades, which separate western and eastern L l i I. ' Oregon, in the Willamette Valley, and in the Coast --)--I-..!.:.', j_ .. Mountains. Stripe rust collected from grasses or wheat was Fig. 1. Wheat-growing areas of Oregon and location of the tested in the greenhouse for pathogenicity on Mountain plots: 1 =Mary's Peak, 975 m; 2 =Tupper, 1,311 Oregon's commercial wheat cultivars and grasses. in; 3 = Dale, 1,615 m; 4 = Meachum, 1,219 in; and 5 To study long-distance spore dispersal, we Tollgate, 1,524 m.

Activity and properties of (−)- S-adenosyl- l-methionine:magnesium-protoporphyrin IX methyltransferase in crude homogenates from wheat seedlings

A direct, rapid assay for the enzyme S-adenosylmethionine:magnesium-protoporphyrin IX methyltransferase (EC 2.1.1.11) is presented. Using the assay developed, the effect of temperature and pH on the activity of the enzyme in a crude homogenate of etiolated wheat seedlings was studied. The pH optimum was found to be 7.7 using phosphate buffer; the enzyme exhibited maximum activity at 37 °C although activity was found to be nearly optimal at 25 °C. The K m (pH 7.7, 25 °C) values determined for Mg-protoporphyrin IX and S-adenosylmethionine were 36 and 48 μM, respectively. Treatment of the crude preparation from etiolated wheat with n-butanol to remove endogenous pigments did not result in a decrease in specific activity of the preparation. A crude preparation from green wheat seedlings when treated with butanol exhibited an activity comparable with that of the etiolated wheat preparation so treated thereby demonstrating that this assay could be used in green plant systems.

Nonphotosynthetic Retardation of Chloroplast Senescence by Light

Excised apical portions of green wheat leaf sections were treated with aminotriazole to prevent formation of new chloroplasts. Illumination retarded the decline in chlorophyll content per leaf section, the disintegration of chloroplast ultrastructure, and the loss of capacity for photosynthetic carbon fixation. We interpret these 3 effects of illumination as facets of a single light effect in retarding chloroplast senescence. This light effect in retarding chloroplast senescence has features differing from characteristics of photosynthetic carbon fixation. For example, A) application of the photosynthetic inhibitor 3-(3,4-dichlorophenyl)-1, 1-dimethylurea did not decrease, and may have even slightly increased, the effectiveness of light; B) although the action spectrum contains peaks in the blue and red regions, it differs from the action spectrum for photosynthetic CO(2) assimilation in wheat; C) in nonphotosynthesizing tissue, application of sugars did not retard chloroplast senescence; D) light saturation was achieved by only a few hundred microwatts/cm(2). Considered together with the well-known light requirement for chloroplast formation, our results indicate that light has a dual, photomorphogenetic control in maintaining the green status of the plant by also exerting a second effect: retarding of senescence of chloroplasts already present.

Plant-growth regulant. Determination of chlorocholine chloride residues in wheat grain, straw, and green wheat foliage

Plant-growth regulant. Determination of chlorocholine chloride residues in wheat grain, straw, and green wheat foliage

Experiments comparing the effects on yields of potatoes of three methods of applying three amounts of NPK fertilizer and the residual effects on following winter wheat

1. Seven experiments with main-crop potatoes on heavy soils from 1962–5 measured yields from 0, 5, 10 or 15 cwt/acre of 13–13–20 fertilizer; (1) broadcast and worked into the soil by seed bed preparations; (2) broadcast on the final seed bed; (3) placed in bands 3 in. from the seed centre. Wheat followed the potatoes and was manured with 0, 5, or 10 cwt/acre (of the equivalent) of 13–13–20 fertilizer, in all combinations with the four amounts of, and the three ways of applying, the fertilizer given for the potatoes.2. Fertilizer greatly increased potato yields and 15 cwt/acre of 13–13–20 was justified, provided it was broadcast. Both methods of broadcasting gave similar yields with 5 or 10 cwt/acre, but working the fertilizer into the seed bed was usually the better method with 15 cwt/acre of the fertilizer. Placing in bands beside the seed was the best method in four experiments with 5 cwt, in two with 10 cwt, but never with 15 cwt/acre of fertilizer.3. Yields of green wheat, and of grain and of straw, were increased by residues of fertilizer applied for the potatoes, but were increased much more by freshly applied fertilizer. The residues increased wheat yields by the same amount as one quarter as much freshly applied fertilizer. The residues had smallest effects when the winter rainfall was largest, and were the same however the fertilizer had been applied.

The Dissemination of Plant Pathogens

A cloud of reddish spore dust arose from a rusted wheat field in southern Mexico and was borne northward on the prevailing winds. It settled finally on some fresh green wheat leaves in Texas. In a few days a billion rust spores were produced on the Texas wheat and carried aloft, again northward. These in turn found some wheat leaves and regenerated their kind. In this hop, skip fashion the wheat stem rust pathogen travelled up through the wheat belt of the central United States and all the way to Canada, some 2000 miles in two months. In its wake lay destruction, the wheat kernels failing to fill and the yield of grain drastically reduced. This dramatic event could be repeated every year were it not for the fact that resistance to this menace has been built into most wheat varieties by our plant scientists, and that a combination of ideal weather conditions must prevail for optimum disease development. It illustrates the ease with which microscopic organisms that cause disease in plants may be disseminated. Countless billions of fungal spores, bacterial cells, viral particles, and nematodes, many with the potential for destruction of plants, are carried literally all over the globe. And many are the ways by which they may be disseminated-by the wind, by splashing rain and running water, by insects, birds, and other animals, and even, unknowingly, by man himself in his daily transport of plant products from place to place. Wind is perhaps the most common means by which plant pathogens, particularly the spores of fungi, are carried. Years ago black clouds of smut spores arose from the combine as it harvested diseased wheat heads along with healthy ones. (Fig. 13) The most gentle of breezes can sweep the tiny spores from their mooring places. A little cloud of blue mold spores, for example, may swirl upward from a rotted orange or lemon as the housewife picks out fruit in the market place. They settle on fresh fruit which in turn may become rotted. Smut spores may shower down from a black gall on a corn plant as the home gardener picks the ripe ears. These spores may produce a new gall or fall to the soil and survive the winter to menace the next year's crop. A grower care-

On the Formation of Protochlorophyll in Normal Green Wheat Leaves of Varying Age

On the Formation of Protochlorophyll in Normal Green Wheat Leaves of Varying Age

Occurrence of Malonic Acid in Plants

THE occurrence of malonic acid has been reported in the leaves of lucerne1 and in green wheat plants2. This acid is well known as a competitive inhibitor of succinic dehydrogenase, and has been used extensively in investigations of the tricarboxylic acid cycle. In consideration of this inhibiting effect of the acid, some further investigations have been made into its presence in plants.

A Study of Spotted and Fallowed Wheat Fields in West Central Kansas

During the spring of 1947, spotted growth areas appeared in many wheat fields in west central Kansas. Such spots had been noted prior to 1947 when the weather was favorable. Seasonal conditions most favorable for such growth are drought in late summer and early fall, followed by ideal growing conditions in late fall and winter. This produces ample vegetation for pasturing of wheat by livestock. The major causes of spotted wheat fields in the past 25 years have been studied by the Kansas Agricultural Experiment Stations'l particularly in those areas of the state where rainfall is relatively light. Research by Lipman(2) and others revealed a great deal about nitrogen supply and deficiency but little about calcium and phosphorus of the soil and their relationship to the grain produced on fallowed fields, and those continuously cropped containing small areas of taller dark green wheat. The areas selected for study were on a farm four miles north of Hays, Kansas, and the project was conducted with the cooperation of the farm operator, Mr. J. D. Fellers. Two fields were chosen for study: A, a continuously cropped field (Fig. 1) and B, a fallowed field adjacent to Field A (Fig. 2). Both of the areas had been farmed by Mr. Fellers and as far as could be determined, the two fields were comparable as to soil type, topography and erosion. Field A (the continuously cropped area) had been in wheat since 1943. In both fields, the seedbed had been prepared by moldboard plowing, spring-toothing to pack the soil and kill volunteer wheat, and harrowing to level the soil just before seeding. Stubble burning had not been practiced in either field. Fields A and B were seeded to Comanche wheat, September 20, 1946. Thirty-four pounds of wheat per acre were used in seeding each field. When wheat pasture was available, both fields had been grazed heavily by a dairy herd during the three years previous to this study. Further reference to the areas studied will be given by the symbols: G for the green spots in the continuously cropped area,