Plants Of Different Varieties Research Articles

Differences in the sterol composition of Heliothis zea fed Zea mays versus Medicago sativa

Larvae of Heliothis zea were fed Zea mays or Medicago sativa in order to determine how these plants affected the development and sterol composition of the insect. The larvae fed corn kernels grew more rapidly than those fed alfalfa leaves. The corn kernels contained Δ 5-24-alkylsterols whereas the leaves as well as the sprouts and flowers of alfalfa contained Δ 7-24-alkylsterols. The corn-fed larvae dealkylated the dietary Δ 5-sterols and utilized primarily cholesterol in their tissues. In contrast, although the larvae fed alfalfa dealkylated the Δ 7-sterols present in the leaves, they were unable to metabolize the B-ring of these sterols and so both the prepupae and adults utilized large quantities of lathosterol in their tissues. Interestingly, H. zea, a generalized feeder, shared its inability to metabolize Δ 7-sterols to Δ 5-sterols with Hypera postica, a specialized feeder on alfalfa. This coleopteran also dealkylated the Δ 7-24-alkylsterols and contained lathosterol, but not cholesterol, in its tissues. Therefore, the ability of H. zea to utilize either Δ 5- or Δ 7-sterols in its tissues may help to explain its ability to complete its development on a variety of different plants, although it may prefer a host, such as corn, that produces Δ 5-sterols and supports a more-rapid rate of growth.

Study of the lignin of cotton plants of the variety AN Bayaut-2. I

The dioxane lignin has been isolated from ripe stems of a cotton plant of the variety AN Bayaut-2. Its developed empirical formula has been derived, its UV, IR, and PMR spectra have been recorded, and its molecular weight has been determined. It has been shown that the dioxane lignins of the stems of cotton plants of different varieties differ in chemical structure.

Limited-host-range plasmid of Agrobacterium tumefaciens: molecular and genetic analyses of transferred DNA.

A tumor-inducing (Ti) plasmid from a strain of Agrobacterium tumefaciens that induces tumors on only a limited range of plants was characterized and compared with the Ti plasmids from strains that induce tumors on a wide range of plants. Whereas all wide-host-range Ti plasmids characterized to date contain closely linked oncogenic loci within a single transferred DNA (T-DNA) region, homology to these loci is divided into two widely separated T-DNA regions on the limited-host-range plasmid. These two plasmid regions, TA-DNA and TB-DNA, are separated by approximately 25 kilobases of DNA which is not maintained in the tumor. The TA-DNA region resembles a deleted form of the wide-host-range TL-DNA and contains a region homologous to the cytokinin biosynthetic gene. However, a region homologous to the two auxin biosynthetic loci of the wide-host-range plasmid mapped within the TB-DNA region. These latter genes play an important role in tumor formation because mutations in these loci result in a loss of virulence on Nicotiana plants. Furthermore, the TB-DNA region alone conferred tumorigenicity onto strains with an intact set of vir genes. Our results suggest that factors within both the T-DNA and the vir regions contribute to the expression of host range in Agrobacterium species. There was a tremendous variation among plants in susceptibility to tumor formation by various A. tumefaciens strains. This variation occurred not only among different plant species, but also among different varieties of plants within the same genus.

Chemical identification of iron reductants exuded by plant roots

Abstract Different varieties of plants exhibit varying abilities to mobilize iron from the soil and to some extent this is dependent upon the reduction of the iron from the ferric form to the ferrous form. Tomato, barley, soybean, and sunflower were studied to identify the iron reductants exuded by roots during periods of iron stress. The tomato reductants were fractionated into one major and at least three minor components. The major component has been identified as chlorogenic acid and considerable data has been collected on the other components. The reductant extract from sunflower has chlorogenic acid as a primary component. The reductant fractions from soybean and barley are similar but different from those of tomato and sunflower. The barley reductants contain glucose and the soybean reductants contain glucose and galactose as well as a ultraviolet light absorbing aglycone.

Stable-isotopic composition of soil carbon dioxide in the Tucson basin, Arizona, U.S.A.

Most models to correct 14C groundwater ages require the δ 13C-value of soil CO 2 in the recharge areas of the aquifer at the time of recharge. Ninety-one soil gas samples were collected at three long-term sites in the Tucson area from July 1980 to June 1981 to determine the extent of seasonal variations and the influence of vegetation on the δ 13C and CO 2 concentration of soil gases. Variations were observed in both δ 13C and CO 2 concentrations. The highest CO 2 concentrations, up to 1.3% at 60-cm depth, were observed during March and April; the lowest, 0.1% CO 2 at 12-cm depth, were observed during the winter months. The δ 13C-values varied by ~ 5‰ during the sampling period. The lowest 13C contents were found in early spring and summer. Part of the δ 13C variation is due to exchange with atmospheric CO 2. Other causes could be decomposition of organic matter with different isotopic composition and different decay rates and/or to a seasonal displacement of the period of maximum activity among different varieties of plants. The mean δ 13C for samples at the long-term sites was ~ −18‰. In addition, fifteen soil gas samples were collected in the bottom of washes which are the assumed recharge areas of the Tucson aquifer. Both CO 2 and 13C concentrations showed changes with time and location. High concentrations of CO 2 of up to 4.8% were found. The mean δ 13C for these samples was ~ −20‰. A major source of CO 2 in the riverbeds is believed to be decomposition of organic matter carried out by the runoff water during the periodic flooding of the washes.

Lipids in Alfalfa Leaves in Relation to Cold Hardiness

The lipid composition of the leaves of hardy Vernal and cold-sensitive Caliverde alfalfa plants, grown at different temperatures, was determined. Phosphatidyl glycerol, phosphatidyl inositol, and the sulfolipid content were directly related to growth temperature. Mono- and digalactose diglyceride and phosphatidyl choline and ethanolamine were inversely related to temperature. At corresponding growth temperatures Vernal plants showed higher percentages of mono- and digalactose diglyceride and phosphatidyl choline and ethanolamine than Caliverde plants, while the opposite was true for phosphatidyl glycerol and inositol and sulfolipid. Differences in fatty acid composition of corresponding leaf lipid fractions of plants grown at different temperatures or differences in fatty acid composition between lipid fractions of plants of different varieties in general were negligible.

Species specificity of ribosomal proteins from chloroplast and cytoplasmic ribosomes of higher plants: Electrophoretic studies

1. The proteins isolated by the LiCl-urea method from chloroplast ribosomes of several different plants are electrophoretically dissimilar from those extracted in a similar manner from the corresponding cytoplasmic ribosomes. 2. The electrophoretic patterns of proteins of cytoplasmic (80-S) ribosomes isolated from plants of different subclasses, different order, different genera, exhibit variable degrees of dissimilarity depending on the degree of taxonomic kinship of the plants from which the ribosomes were derived. The electrophoretic patterns of proteins extracted from plants of different varieties and species are identical. 3. The electrophoretic patterns of proteins isolated from the chloroplast (70-S) ribosomes of plants of different subclasses, of different order and of different genera exhibit a higher degree of electrophoretic dissimilarity than those of the corresponding 80-S ribosomes; i.e., in general in differently related plants the patterns obtained from cytoplasmic ribosomes tend to be more congruent than those of the 70-S ribosomes.

Studies on the Seed Production of Soybean : 5. Varietal differences in photosynthetic rate of soybean.

This study was carried out to verify the varietal difference in the activity of photosynthesis per unit of leaf area and the stability against environmental conditions. For this study, the leaves adhering to the soybean plants were used as sample and the activity of photosynthesis was measured at the stage when the leaves showed the maximum photosynthetic rate, in the laboratory under the conditions of the saturated light intensity at leaf temperature of 26 to 29°C, with ordinary atomospheric concentration of CO2. The results are as follows: 1. Coefficient of variation in photosynthesis among plants of different varieties varied as much as 5 to 25 percent. 2. Variations in photosynthetic rates among varieties were less than some ± 20 percent as against the aggregate average rate of all the different varieties. 3. Absolute vaule of photosynthesis varied with the environmental conditions, but it was verified that the varieties of high activity of photosynthesis indicated high rates of photosynthesis without exception, when all the different varieties were tested in comparison. 4. Varietal difference being found in the photosynthetic rate according to different varieties as stated above, photosynthetic rate can be taken as a target characteristic for selection in the breeding process.

Seed Lipids

Many of the newly discovered seedoil acids have reactive or unusual functional groups or other facets of molecular structure that permit their ready differentiation from oleic, linoleic, linolenic, and the other most prevalent saturated and unsaturated long-chain fatty acids. The recognition and availability of the new acids, coupled with methods that make detection and determination easy, will help studies of lipid biosynthesis in the plant and of lipid metabolism and utilization in animals, and will stimulate more studies in depth on the fine points of seedlipid structure. Correlations of structural patterns in seed lipids of particular groups of plants with classical taxonomic categories will permit clarifications, raise needed questions concerning classifications, and accelerate research in chemotaxonomy and phylogenetics. Seed lipids are particularly well suited for establishing relationships among plants because of their great variety in structure compared to the more limited structural types of amino acids, sugars, purines, and many other plant substances. The newly characterized seed oils are potentially important industrial raw materials whenever they come from agronomically promising plant species. The molecular structures of seed triglycerides have major influence on their physical properties and therefore advances in knowledge in that sphere have practical implications. For example, the unusual characteristics of cocoa butter that make it so valuable for food and confectionery use are attributed to the specific arrangement of fatty acids it its triglycerides. The glycerides are almost all 2-oleic-1,3-disaturated acid triglycerides. The physical characteristics of lard are advantageously changed by catalytically rearranging fatty acyl groups among the glycerides initially in the fat to achieve a more nearly random distribution, followed sometimes by further fractionation to remove more saturated glycerides. Through this change of glyceride structures a preferred, less grainy texture is achieved. Future studies to understand, unravel, and control seed-oil triglyceride structures will be significant in developing margarines of improved texture and "feel," cocoa-butter substitutes, and many other products. I expect rapid, fruitful progress in seedlipid research and utilization to continue. Such progress will be aided by investigation of seed lipids from a large number and variety of different plants to find new types of fatty acids, to find new sources of familiar oils, and to obtain more data regarding their glyceride structures.

Effects of Photoperiodism and Other Factors on the Improvement of Pigeonpea Varieties

Studies on the effects of photoperiodism and other factors were conducted to obtain information which might be useful in a breeding program with pigeonpeas. The information was sought for accelerating this work in a region where extremes of day-length vary by only 2 hours because of its location in latitude 18°. By shortening the length of day to 8 hours through the use of a darkroom, and planting during the month of February, it was possible to induce flower formation 4 months earlier in two early varieties and 7 weeks earlier in a late variety. However, this short-day treatment did not appreciably affect the time of flower induction in an all-season, or "Totiempo" variety. One-gallon tin-can containers and 10-inch polyethylene bags were found satisfactory for growing pigeonpea plants of different varieties.

Effects of chronic gamma irradiation in Durum and bread wheats

Plants of different varieties of durum and bread wheats were subjected to several dose rates of chronic gamma irradiation for the whole of their life cycle or allowed to recover after 38 or 56 days of irradiation. In plants subjected to daily exposures of 148 and 72 r with or without a recovery period, the following growth reactions were observed: (1) increase in the mean number of culms per plant and (2) increase in the mean weight per mature plant. In both durum and bread wheats the strongest tillering reaction was typical of the late varieties. Analysis of the number of spikes per plant showed that three out of the ten varieties tested formed spikes in greater number than the controls at 148 r/day chronic exposure; an increase in mean number of spikes per plant was observed in most of the varieties at 52 and 72 r/day. Spikelet fertility and germinability of seeds produced by irradiated plants showed that the group of bread wheat varieties, as a whole, is more radiation resistant than the group of durum wheat varieties. Among these, Aziziah appeared the most radiation sensitive, and Cappelli the most radioresistant.

Factors Affecting Rate of Honeydew Deposition by Therioaphis maculata (Buck.) and Toxoptera graminum (Rond.)1

Various factors affecting the rate of honeydew deposition by the greenbug ( Toxoptera graminum (Rond.)) and the spotted alfalfa aphid ( Therioaphis maculate (Buck.)) were studied and the reactions of the two species compared. A method was developed whereby honeydew droplets from one aphid feeding for a '24-hour period on a plant part were caught on the bottom or sides of plastic cages. The rate of honeydew deposition was affected significantly in both the greenbug and the spotted alfalfa aphid by: (1) changes in temperatures; (2) different plant parts as feeding sites (leaf, stem, petiole); (8) different varieties of plants; and (4) the amount of light reaching the host plant and feeding site. The following factors were found to affect significantly the rate of honeydew deposition by the greenbug: (1) the area of feeding on a Reno barley leaf; (2) feeding on leaves yellowed by age; (8) reduced moisture to host plant. Changes in the following factors or conditions did not affect significantly the rate of honeydew deposition by the spotted alfalfa aphid: (1) reduced moisture to host plant or (!t) distance of leaves from growing point. The rate of honeydew deposition on Reno and Dicktoo barley and Pawnee wheat exceeded that found on the alfalfa varieties studied. This implies that the problems resulting from honeydew might be as great on barley and wheat as on alfalfa if it were not for the different methods in cultivation and harvesting time. The rate of honeydew deposition was found to be influenced almost directly in proportion to the known amount of resistance found in the host plants used. This condition suggests the possibility that the rate of honeydew deposition by aphids may be used to measure the degree of resistance of host plants to aphids, the rate of ingestion of plant material, and to serve as a crude measure of the metabolic activity of the insect.

COMPARATIVE DEVELOPMENT OF TWO WHEAT VARIETIES UNDER VARYING MOISTURE SUPPLY

Two varieties of wheat, Lutescens and a cross of Reward × Caesium, were both grown in the greenhouse at four levels of soil moisture supply. The plants produced were harvested individually and subjected to structural counts, measurements, and weighings designed to illustrate certain components of growth and yield.Significant effects of moisture supply on number, height, and weight of shoots, number of fertile heads, and weight, size, and nitrogen content of grain per plant and per shoot, differing in some cases in the two varieties, were demonstrable. The relation between the production of straw and fruiting parts per tiller also seemed to be a varietal characteristic. It is suggested that, observations of this type, under field plot conditions, on a relatively small number of plants grown under controlled moisture supply, might provide useful information respecting the adaptability of different varieties of plants.

The Presence of Urease in the Nodules on the Roots of Leguminous Plants

AFTER the discovery of urease in the Soya bean by Takeuchi in 1909, the presence of this remarkable urea-splitting enzyme was soon recognised in the seeds of many leguminous plants. On the other hand, while the occurrence of the enzyme in seeds from widely different varieties of plants has been recorded in recent years, its absence from the seeds of several Leguminosæ has also been noted.

Coffee parasites

The reconstitution of European vineyards after the phylloxera outbreak was performed with few high-aptitude varieties. In Navarre (Spain), the variety used was mainly ‘Garnacha’, though the inclusion of a small number of plants of different varieties traditionally grown in this area within each vineyard was relatively frequent. In this context, in 2008 and 2009, a systematic survey was performed on the oldest vineyards (>50 years) from Navarre in order to gather the intravarietal diversity that could be found within ‘Garnacha’ in the region, but subsequent field observation showed 197 plants to be different from ‘Garnacha’. The aim of this study was to identify the varieties corresponding to those plants. Molecular profiles were determined using 25 SSR markers, and 33 varieties were identified: 28 of them after comparisons with national and international databases and the remaining five through other sources. Slight differences in SSR allele length were found in some of the plants identified as ‘Mazuelo’, ‘Rojal’, ‘Miguel de Arco’ and ‘Tortozona Tinta’. In addition, polymorphisms involving the appearance of a third allele were found in some plants identified as ‘Viura’, ‘Mandón’, Mazuelo’ and ‘Morate’. This study shows that an important biodiversity reservoir still remains within old vineyards and, therefore, systematic surveys on them could allow gathering the varietal richness that still can be found in the region. Additionally, somatic variation at SSR loci has been shown to occur in several grape varieties, especially in the ancient ones where the likelihood that mutations are accumulated and fixed is higher.

Scientific Serials

THE Journal of the Chemical Society for December 1875 contains the following papers communicated to the Society:—On the agricultural chemistry of the tea-plantations of India, by J. Campbell-Brown, D.Sc. This lengthy paper contains analyses of the young and old leaves of good plants and of stunted and blighted plants of different varieties, analyses of the wood of good and stunted tea-plants of different varieties, analyses of tea-seed, of the soils of tea-plantations, and of tea from manured and unmanured plants. The author discusses also the analytical results.—On certain new reactions of tungsten, by Prof. J. W. Mallett, of the University of Virginia. The author has lound, contrary to the statements in text-books, that the precipitate produced by hydrochloric acid in a solution of an alkaline tungstate is soluble in an excess of the concentrated acid. By adding fragments of metallic zinc to the above-named acid solution, various colours are produced, the most noteworthy being a brilliant magenta. Potassium sulphocyanate and metallic zinc added to the acid solution produce a rich green colour, but when the sulpliocyanate is added first to the alkaline tungstate solution, then a considerable quantity of water, then hydrochloric acid, and finally zinc, a fine amethyst colour is produced. The blue colour well known as characteristic of one of the lower oxides of tungsten may be best brought out by the use of hyposulphurous acid (H2SO2) as the reducing agent.—The remainder of the journal contains the usual collection of abstracts.