Cent Of Dry Weight Research Articles

Laser-disintegrated copper-activated salicylic acid (Cu-SA) nanoparticles suppressed the seed-borne pathogens of rice with enhanced seed invigoration parameters.

Leading phytopathological research is focused on managing seed-borne pathogens of rice through the utilization of engineered nanomaterials. Herein, blue laser-induced topo-morphologically nano-advanced copper salicylates (Cu-SA) (Cu/SA in 1:1 and 1:2 ratio) were prepared and evaluated for their augmented antifungal potential along seed invigoration effects in contrast to their prepared sonicated formulations. Laser disintegration on the Cu-SA (Cu/SA in 1:1 and 1:2 ratio) was achieved with high degree of success and precision using blue laser, which yielded uniformly distributed spherical nanoparticles with a narrow size distribution and better crystallinity than aqua-dispersed sonicated formulations. In vitro antifungal evaluation against seed-borne fungi of rice viz. Fusarium verticillioides and Fusarium fujikuroi revealed multiple times the augmented potential of laser-disintegrated nanoformulations (l-CuSA) than sonicated (s-CuSA) and bulk samples. Laser-induced nano-sodium bis(2-oxobenzoato)cuprate (II) (l-CuSA2) with Cu/SA in 1:2 ratio was the best to inhibit the in vitro fungal growth. Ultra-micrographs and fungal double-staining assay further rationalized the membrane disruption as the mode of action for the fungitoxicity. Nanopriming of fungal infested rice seeds with l-CuSA2 at 2500 μg/mL for 8 h showed the maximum reduction of seed rot (80.43%) and seedling blight (63.15%) with respect to control (untreated). The seed-invigorating factors of l-CuSA2 nanoprimed seeds were enhanced to maximum extent and showed the highest per cent germination (35.29%), shoot length (11.42%), root length (21.14%), dry weight (75.43%) and vigour index (81.04%) over the control. Inclusively, the seed nanopriming with l-CuSA2 proved as agro-compatible hypo-toxic semi natural nanoplatform for sustainable agriculture.

Pogostemon benghalensis essential oil inhibited the weed growth via causing oxidative damage

The present study was conducted to evaluate the phytotoxic potential of Pogostemon oil in terms of oxidative stress on two weeds, viz. Avena fatua L. and Phalaris minor Retz. GC–MS analysis revealed that Pogostemon oil is rich in sesquiterpenes with azulen-2-ol, 1,4-dimethyl-7-(1-methyl ethyl)-as the major component of the oil with maximum % area (28.2%). For the laboratory bioassay, oil emulsion of different concentrations, ranging from 0.25 to 2.5 mg mL−1, was prepared. The effect of oil treatment was studied on per cent germination, seedling length, chlorophyll content and dry weight of the test plants. The inhibitory effect of Pogostemon oil was much pronounced on Avena fatua as compared to Phalaris minor. Roots were adversely affected due to oxidative damage. Consequently, oxidative damage, IC30, IC50 and IC70 values for A. fatua were calculated. Pogostemon oil treatment induced excessive generation of ROS leading to oxidative stress in test plant. ROS further disintegrated membrane integrity as evident from the increased level of MDA, REL and decreased level of CDs. Further exposure to Pogostemon oil enhanced the activities of antioxidant enzymes, thus indicating the activation of ROS scavenging mechanism. Thus, Pogostemon oil inhibits the growth of test plant via inducing oxidative stress and therefore shows potential towards weed management.

Toxic affects of chromium on some quality parameters of Sorghum bicolor (L.)

A pot experiment was conducted to determine the effects of varying Cr (VI) levels [0.0–4.0 mg Cr (VI) kg-1 soil in the form of potassium dichromate] on the some quality parameters of sorghum Sorghum bicolor (L.). Quality parameters was measured in terms of protein content, chlorophyll content, and IVDMD ( In vitro dry matter digestibility) content at different growth stages, i.e. 35 DAS, 70 DAS and 90 DAS (Days after sowing) that were adversely affected with an increase in Cr (VI) levels from 0.0 to 4.0 mg Cr (VI) kg-1 soil. The decline in protein content 4.67 g/ kg dry weight at T4 was observed as compared to control (T1) ( 8.96 g/kg dry weight basis) at 35 DAS in leaves , Total chlorophyll content declined from 3.25 mg g-1 fresh weight (T1) to 2.40 mg g-1 fresh weight (T4) at 35 DAS and IVDMD content declined from 43.60 to 33.60 per cent dry weight basis with increment in chromium concentration. It is concluded that Cr (VI) at higher doses (4.0 mg Cr (VI) kg-1 soil) adversly affects the quality parameters of Forage sorghum Sorghum bicolor (L.) however, quality parameters are responsible for nutritive value of sorghum Sorghum bicolor (L.).

Effects of Type of Cutting, IBA and Bioinoculants on Rooting in Madhunashini (Gymnema sylvestre Retz.)

An experiment was carried out to study the effect of type of cutting, IBA and bioinoculants on rooting in madhunashini. Among the three types of cuttings, hardwood cuttings registered higher values for fresh (0.790g/cutting) and dry weight (0.650g/cutting) of sprouts, per cent rooting (6.66 %), fresh and dry weight of roots (0.037 and 0.030g/ cutting) and biomass production (0.682g/cutting). Among IBA and bioinoculant treatments, Azotobacter chroococcum recorded higher values for percentage sprouting (26.66 %) and rooting (9.99 %) as also for other root parameters; whereas, maximum fresh weight (0.863g/cutting) and dry weight of sprouts (0.740g/cutting), and, biomass production (0.759g/cutting) was observed in IBA 1000ppm treatment. Interaction effect of type of cutting, IBA and bioinoculants on fresh and dry weight of sprouts (2.438g and 2.084g, respectively) and biomass production (2.123g/cutting) was found superior in hardwood cuttings treated with IBA 1000ppm. Percentage of rooting (13.33 %) was better in hardwood cuttings treated with Azotobacter chroococcum. Therefore, among the various treatments tested, hardwood cuttings treated with Azotobacter chroococcum are the best for propagation through cuttings.

Nitrate accumulation, growth and leaf quality of spinach beet (Beta vulgaris Linn.) as affected by NPK fertilization with special reference to potassium

The present study was carried out at the Herbal Garden of Jamia Hamdard, New Delhi on Pusa Bharti variety of Spinach Beet ( Beta vulgari s Linn.) to understand the effect of potassium with other fertilizers on nitrate accumulation, growth and quality of the leaves. Potassium application along with other fertilizers increased leaf area, per cent dry weight, Chlorophyll Content Index (CCI) and Nitrate Reductase Activity (NRA), but decreased nitrate content. Effect of 2:1 ratio of N and K was found statistically at par with 1:1 ratio of N and K. Fertilizer treatments without potassium had lower level of NRA and higher nitrate content in the leaves as compared to other applications. Application of FYM along with NPK fertilizers increased leaf area, per cent dry weight, CCI and NRA, whereas it decreases nitrate content. As higher NRA and lower nitrate content was recorded in treatments with potassium, application of K is desirable to reduce health hazards related with nitrate toxicity. Based on the results of the study, application of 1:1 ratio of N and K fertilizer and FYM is recommended.

Nitrate accumulation, growth and leaf quality of spinach beet (Beta vulgaris Linn.) as affected by NPK fertilization with special reference to potassium

The present study was carried out at the Herbal Garden of Jamia Hamdard, New Delhi on Pusa Bharti variety of Spinach Beet (Beta vulgaris Linn.) to understand the effect of potassium with other fertilizers on nitrate accumulation, growth and quality of the leaves. Potassium application along with other fertilizers increased leaf area, per cent dry weight, Chlorophyll Content Index (CCI) and Nitrate Reductase Activity (NRA), but decreased nitrate content. Effect of 2:1 ratio of N and K was found statistically at par with 1:1 ratio of N and K. Fertilizer treatments without potassium had lower level of NRA and higher nitrate content in the leaves as compared to other applications. Application of FYM along with NPK fertilizers increased leaf area, per cent dry weight, CCI and NRA, whereas it decreases nitrate content. As higher NRA and lower nitrate content was recorded in treatments with potassium, application of K is desirable to reduce health hazards related with nitrate toxicity. Based on the results of the study, application of 1:1 ratio of N and K fertilizer and FYM is recommended. Keywords: Spinach beet, potassium, nitrate toxicity, nitrate reductase, manure; fertilizers, NPK.

Changes in proximate and amino acid composition during early development of two Australian Percichthyid fish, Macquarie perch, Macquaria australasica Cuvier, and trout cod, Maccullochella macquarensis (Cuvier)

In the present paper, the results of a study on changes in the proximate and amino acid composition of the eggs and larvae of two Australian native Percichthyid fish, Macquarie perch, Macquaria australasica Cuvier, and trout cod, Maccullochella macquarensis (Cuvier), are presented. The stages of development studied were unfertilized and fertilized eggs, newly hatched larvae, and post-yolk-sac larvae (in Macquarie perch only). In Macquarie perch, significant changes in moisture content occurred throughout development, but this was not so in trout cod. The protein content (per cent dry weight) in Macquarie perch larvae only decreased significantly after hatching (P < 0.05). On the other hand, the total lipid (by dry weight) increased significantly during this transformation (P < 0.05), and decreased significantly in yolk-sac-resorbed larvae. In trout cod, the protein and lipid content did not change significantly up to hatching. The ash content increased significantly in newly hatched and yolk-sac-resorbed larvae of both species. The total amino acid contents of unfertilized eggs, fertilized eggs, newly hatched larvae and yolk-sac-resorbed larvae of Macquarie perch and trout cod were 5752, 4652, 3696 and 2723 μmol g−1 (dry weight), and 4688. 3448 and 2329 μmol g−1, respectively. In the amino acid pool in Macquarie perch, the essential amino acids (EAAs) leucine, isoleucine and valine, and the non-essential amino acids (NEAAs) alanine, aspargine and glutamate occurred in the greatest quantities in non-fertilized eggs, and the cysteine content was the smallest. In Macquarie perch, five out of nine EAAs (i.e. isoleucine, leucine, lysine, threonine and valine) and six out of eight NEAAs (i.e. alanine, asparagine, glutamate, glycine, proline and serine) decreased significantly (P < 0.05) from one developmental stage to the other. In trout cod, all the EAAs, barring lysine and all the NEAAs decreased significantly with development.

The effect of dietary changes on plasma lipids and lipoproteins of six Labrador Retrievers

Six healthy, spayed female Labrador Retrievers (aged 5·5 to 11 years), kept under controlled conditions of exercise and housing, were fed a diet of 15 per cent fat, 24 per cent carbohydrate and 33 per cent protein for two weeks before and between each of three test diets, of differing fat to carbohydrate ratios (A 13:44, B 20:33, C 25:26 fat:carbohydrate gm per cent dry weight) given in a predetermined order for four weeks each. Fasting plasma lipoproteins and total fatty acids were measured weekly. In the fourth week of each test period post-prandial plasma lipoproteins were measured. Diets B and C increased total (P<0·001) and LDL cholesterol (P<0.05) whilst diet A increased HDL triglyceride (P<0·05). Eicosapentaenoic acid (C20:5) increased on diets B and C, and oleic acid (C18:1) on diet A. Post-prandial hypertriglyceridaemia occurred on all diets. Chylomicron clearance was slower on higher fat diets. Relatively small dietary changes produced significant alterations of plasma lipids, lipoproteins and chylomicron clearance.

The influence of lifestyle and diet on the lipoprotein profile of Border Collies

Plasma lipoprotein cholesterol and triglycerides Were determined in two groups of Border Collies, one actively working and the other pets. Baseline concentrations of total, low density lipoprotein ( LDL) and high density lipoprotein ( HDL) cholesterol Were higher, and HDL triglyceride concentrations lower in the pet dogs. Lifestyle of the dogs was assessed by questionnaire completed by the owners. Measurement of exercise was made by visual observation and using a Caltrac activity monitor. The Working dogs were a homogenous group with respect to lifestyle and diet, but the pet dogs showed differences in lipoprotein profile relating to housing, dietary fat and exercise intensity. Two diets with different levels of dietary fat (13 and 20 per cent dry weight) were given for two months each. After two months on either of the diets the cholesterol concentration of the working dogs increased and HDL triglyceride concentration decreased, and there were no significant differences between the groups, but very low density lipoprotein ( VLDL) triglyceride increased significantly in the less active pet dogs.

In Vitro Culture and Regeneration of Solanum khasianum and Extraction of Solasodine

Leaf explants of Solanum khasianum regenerated on MS medium containing 2, 4-D (3 mg/l) and kinetin (1 mg/l). Shoots could be induced from these calli on medium containing BAP (3 mg/l) alone. Rhizogenesis of these shoots occurred when transferred to medium containing 2 mg/l NAA. The yield of solasodine — a pharmaceutically important compound, from 4-month-old callus tissue was remarkable at 2 per cent of dry weight.

Growth hormone influences collagen deposition and mechanical strength of intact rat skin. A dose-response study.

The influence of biosynthetic human growth hormone on biomechanical properties (strain at maximum load, maximum load, relative failure energy, maximum stiffness) and collagen content of intact rat skin was measured after injection of biosynthetic human growth hormone for 90 days at doses of 0.16, 1.10 and 8.33 mg.kg-1.day-1. The mechanical test showed that strain at maximum load, maximum load and relative failure energy increased with increasing doses of biosynthetic hGH. In the group receiving 8.33 mg.kg-1.day-1, skin collagen content per surface area and skin collagen concentration in per cent of dry weight were increased, whereas the fat concentration in per cent of dry weight was decreased. Also when correcting the mechanical data for cross-sectional area, a positive correlation between dose and relative failure energy was found. When dividing the mechanical data by collagen content per surface area of the skin, the maximum stress and relative failure energy reached the highest value at a dose of 1.10 mg.kg-1.day-1. The study shows that biosynthetic hGH can induce an increase in collagen content and mechanical strength of intact rat skin which is dependent on the dose of biosynthetic hGH, and that the increase in mechanical strength cannot be explained only by an increased collagen content.

Enhanced Rubber Accumulation and Rubber Transferase Activity in Guayule Under Water Stress

Effects of water stress on rubber accumulation and on the activities of rubber transferase (Cis-1,4-polyisoprenyl transferase) were investigated in field-grown guayule ( Parthenium argentatum Gray) plants. A pronounced increase in the activities of rubber transferase was recorded in the stressed plants. An increase in enzyme activity was observed with decreased leaf water potential (ψ) from -0.5 MPa to -2.5 MPa and the activity declined thereafter. The rubber yield (per individual plant and on a per cent dry weight basis) also increased with a decrease in ψ value upto -2.5 MPa, followed by a sharp decline. Rewatering of the guayule plants increased the ψ value, followed by a continuous decline in the transferase activity over the next 9 days. The results indicate that maintainance of low leaf water potentials is advantageous for maximized rubber accumulation in guayule. The increased levels of rubber transferase activity during water stress were attributed to a shift in de novo synthesis of the enzyme, resulting altered patterns of rubber accumulation in guayule. The results point to a clear correlation between the ability of guayule to grow in arid areas and its better performance in rubber accumulation under controlled water-stress conditions.

Feeding, digestion and assimilation of a population of giant tortoises (Geochelone gigantea (Sehweigger)) on Aldabra atoll

This paper describes an investigation of food processing by the Giant Tortoise (Geochelone gigantea (Schweigger)) on Aldabra atoll in the Indian Ocean. The dry weight assimilation efficiency of the Aldabran tortoise feeding on tortoise turf was found to be 30 per cent, while energy assimilation was calculated as 34·5 per cent. Weight specific consumption varied with body size according to diet and season. Some hollocellulose was broken down during the passage of food through the gut, but it is not clear whether cellulose breakdown is a regular feature of tortoise digestion. Throughput times for passage of food through the gut show a log-normal distribution with median throughput time of 8·8 days on tortoise turf and 12·0 days on the much coarser coastal grass Sporobolus virginicus (L.). Body composition was determined by the dissection of 8 animals. Gut contents accounted for 15 per cent of live weight, and skin, bone and scute for a further 47 per cent, or 68 per cent of dry weight. The average calorific value of tortoise tissue (excluding gut contents) was calculated as 4274 kJ/kg (fresh weight). Results on consumption and assimilation rates and energy contents were combined with data from earlier studies to produce an animal energy budget for the South East Grande Terre population. Discussion focuses on features of the energy budget of this population, which supports a high standing crop biomass on low rates of consumption and assimilation. Both turnover rates (P/B) and production efficiency (P/A) are below 1 per cent and the population appears to be food-limited. Comparisons are made with African wildlife areas with similar rainfall, dominated by large herbivorous mammals, particularly those dominated by elephant, and with lower density tortoise populations on other Aldabra islands. The interactions of food supply, growth rates, reproductive rates and population density are discussed.

Effects on dry weight and nitrogen content of grains of semi‐dwarf and tall varieties of winter wheat caused by decreasing the number of grains per ear

SUMMARYThe number of grains in ears of six varieties of winter wheat growing in the field was decreased by removing the top half of the ear 6 days after anthesis (halving). In the semi‐dwarf varieties Hustler, Sentry and Hobbit, and in the taller varieties Armada and Flanders, the mean dry weight per grain in the lower six spikelets of halved ears was about 23% greater than the dry weight of grains in the comparable part of intact ears. In Maris Huntsman the increase in grain size amounted to only 13%. Halving increased the number of grains in the semi‐dwarf varieties but not in the others. Consequently, the increases caused by halving in the total weight of grain in the lower six spikelets ranged from 41% in Hustler and Hobbit to 7% in Maris Huntsman.Halving increased the amount of nitrogen in the grain of the lower half of the ear similarly in all varieties, and relatively more than it increased dry weight. So nitrogen per cent dry weight of grain was increased, especially in Armada, Flanders and Maris Huntsman which responded least in dry weight. The uptake of nitrogen into the stem plus ear after anthesis was unaffected by halving. Most of the nitrogen that normally moved to the upper grains accumulated in the lower grains of halved ears.More nitrogen moved into the grain of intact ears of tall than of semi‐dwarf varieties after anthesis, because there was greater uptake of nitrogen into the shoot from the roots.

Arsenic accumulation, tolerance and genotypic variation in plants on arsenical mine wastes in S.W. England

Abstract Mine and smelter wastes in S.W.England, containing high concentrations of arsenic and other elements have been investigated. Several soil profiles were examined in detail for water soluble and ‘total’ arsenic, copper and iron levels. Macroelement and pH values were also obtained. The spoil material was highly acidic, deficient in macro‐elements and contained elevated levels of arsenic and iron. Concentrations of water soluble extracts of both arsenic and iron increased markedly down the profile. The conditions have given rise to a specialized arsenic‐tolerant flora which is both impoverished and restricted. Plant cover is generally less than 1 per cent on the very toxic areas. Plants present on the sites include Agrostis tenuis, Agrostis stolonifera, Agrostis canina and Jasione montana. These species were found to accumulate arsenic to high concentrations which, in some cases, approached 1 per cent dry weight. Clonal material of A. tenuis and A. stolonifera from high arsenic sites exhibited toler...

Use of concept of distance and group constellation for classifying the susceptibility of sorghum varieties to Ephestia cautella (Walker)

Ephestia cautella (Walker) was reared on ten sorghum varieties at 30°C and 70 ± 5% r.h. Average developmental period, per cent adult emergence and dry weight of the adult insects was recorded on each variety. Significantly poor adult emergence was recorded on 77 K 1262, CSV-5 and IS 7002. Larvae developed quickly on Swarna, CSV-2, CSV-3, CSV-4 and Sel. 472 and slowly on IS 4776 and IS 7002. Using a computed growth index the varieties can be grouped into six different categories. Distance analysis and group constellation indicated six distinct clusters. Similar clustering was also observed through canonical variate analysis which matches with the clusters obtained from D 2 statistics. The contribution of different nutritional characters in creating diversity among sorghum varieties revealed that per cent survival contributed maximum towards the divergence of the varieties.

Concentrations and temporal variations of 210Po, 210Pb, and Al in the surf zone ecosystem of Copalis Beach, Washington

Surf diatoms monitored during a 21-month period at Copalis Beach, Washington, contained elevated concentrations of Al, 210Pb, and supported 210Po compared to net phytoplankton from Washington coastal waters and Puget Sound. Aluminum concentrations of several per cent dry weight found in the surf diatoms were not a reflection of contamination by discrete inorganic particulate matter but were the result of a natural coating of clay-sized particles on Chaetoceros armatum, the predominant diatom in the surf blooms. A high correlation between Al and 210Pb in the surf diatoms suggests 210Pb and supported 210Po were also associated with the clay-sized particles. During fall through spring, the unsupported 210Po concentrations in the surf diatoms were correlated with the input of 210Po by precipitation. A summer maximum in unsupported 210Po concentrations in the surf diatoms may reflect upwelling that causes higher dissolved 210Po concentrations in the summer surf relative to those of late spring and early fall. The consumers of the surf diatoms exhibited larger 210Po-activity-to- 210Pb-activity ratios than their food, indicating 210Po was preferentially accumulated in the higher trophic level.

Food utilization and metabolic efficiency in larval and adult house crickets

The most rapid growth of the fat body, ovaries and residual body occurred only at the time of maximal feeding, which was the time of highest metabolic rate. Larvae ceased feeding before the next moult and lost weight. Adult females did not cease feeding and never lost weight. Mated females maintained a high feeding rate that corresponded to a constant oviposition rate with no gonotrophic cycles. Virgin females maintained a lower feeding rate and maintained fully mature eggs in a viable state for life. Growth during the last larval stadium was entirely somatic and characterized by a great accumulation of a lipid rich (65%) fat body. Net growth during the first 10 days of adult life was entirely gonodal, because the small amount of residual body growth was matched by the amount of fat body loss. However, since the residual body was 60% protein and the fat body was 60% lipid, some of the somatic protein growth had to come from the diet and some of the fat body lipid went for ovarial growth. The 20% dietary protein was more than sufficient for all somatic and ovarial growth, and some protein was catabolized for energy. The amount of uric acid in larval faeces accounted for almost all protein catabolism, but in adult females half of the catabolized protein nitrogen did not appear in the faeces. With only 5% dietary lipid both larvae and adults had to synthesize additional lipids from carbohydrates to supplement absorbed lipids for growth demands. Almost all absorbed and synthesized lipids were used for somatic growth in the larvae and for ovarial growth in the adults, because the per cent of food calories used for growth greatly exceeded the per cent dry weight of food used for growth. Based on the calories and dry weight of available fuel, almost all energy production was based on carbohydrate oxidation. Some carbohydrate was used for lipid synthesis but very little was used for growth. Probably the absorption efficiency (72%) and growth efficiency (28%) was the same for both the last instar larvae and virgin females because they ate exactly the same food. However, the larval metabolic efficiency (42%) was higher than that of females (37%), which indicated that more of the absorbed food was converted to tissue during larval growth (somatic) than during adult growth (ovarial). Of the dry weight of food eaten during the last larval stadium, 30% was egested, 32% was oxidized, 28% appeared as growth, and 10% was condensed to lipid and became part of the 28% growth. Of the dry weight of food eaten during the first 10 days of adult life, 27% was egested, 41% was oxidized, 25% appeared as growth, and 6% was condensed to lipid.

Étude des fractions glycanniques des glycosphingolipides totaux de la membrane des globules lipidiques du lait de femme

Human milk fat globule membranes have been prepared according to Brunner's procedure : isolation of the cream by low speed centrifugation, three washings by 0.25 M saccharose containing 0.002 M MgCl 2 , freezing and thawing, vigourous shaking, washing and lyophilisation. 900 mg of membranes are obtained from 1 liter of milk. Glycosphingolipidic fractions are isolated by the Folch method : extraction by chloroform methanol (2 : 1 and 1 : 2, v : v), then partition by adding 0.2 volume of water. The two phases are further purified by Sephadex LH 20 chromatography, leading to the « Purified aqueous phase(15 to 20 mg per liter of milk) and to the « Organic phase . The « Purified organic phase(20 to 25 mg per liter of milk) is obtained after a further purification on silicic acid column (Biosil A) to eliminate the neutral lipids. Purity of the various fractions has been checked by thin layer chromatography ; compounds are revealed by either orcinol, resorcinol or molybdic acid reagents. In addition, absence of milk oligosaccharides has been checked by reduction with tritiated sodium borohydride. The carbohydrate content has been determined by colorimetric methods and the molar ratio has been obtained by gas liquid chromatography of the trifluoroacetylated methylglucosides. The results are as follow (per cent of dry weight) : « Purified organic phase: galactose + glucose : 4.2, N -acetylglucosamine : 0, N -acetylneuraminic acid : 0 ; « Purified aqueous phase: galactose + glucose + fucose : 9.1, N -acetylglucosamine : 1.4, N -acetylneuraminic acid : 3.5. The composition in sphingosine and sphingosine derivatives has been determined after hydrolysis and further identification by thin layer chromatography. The carbohydrate moieties of glycosphingolipids have been cleaved from the ceramides according to Hakomori's procedure : periodic oxidation (catalyzed by osmium tetraoxyde) of the acetylated glycosphingolipids. After deacetylation and purification on Dowex 50 × 8 resin, the obtained mono- and oligosaccharides have been identified by paper chromatography, by determination of the reducing end and by the study of the oligosaccharides liberated after partial hydrolysis. From the « Purified organic phasewe obtained lactose only, and from the « Purified aqueous phasewe obtained : lactose, fucosidolactose, lacto- N -fucopentaose I,lacto- N -difucohexaose and neuraminyl-lactose. This results exclude the possibility that milk oligosaccharides are generated from the catabolism of the glycosphingolipid from milk fat globule membranes. In fact, the carbohydrate moieties of glycosphingolipids is only a few per cents in weight of the total milk oligosaccharide content (7 to 12 g per liter). However, one may consider that the metabolism of the carbohydrate moieties of glycosphingolipids is correlated with the metabolism of blood group substances in a process involving glycosyltransferases and lactose as acceptor. Les fractions glucidiques des glycosphingolipides extraits des membranes isolées des globules lipidiques du lait de Femme ont été détachées des céramides par le procédé de Hakomori et identifiées au lactose, au fucosido-lactose, au lacto- N -fucopentaose I, au lacto- N -difucohexaose et au neuraminyl-lactose. Tous ces glucides sont des constituants du « gynolactosede M. Polonovski et A. Lespagnol. Cependant, nous pouvons exclure l'hypothèse que les oligosaccharides du lait de Femme proviennent du catabolisme des glycosphingolipides des membranes des globules. En effet, plusieurs dizaines d'autres oligosaccharides existent dans le lait de Femme qui ne sont pas des constituants des glycosphingolipides des globules lipidiques. En outre, les glycolipides ne représentent qu'une masse très faible en regard de celle des oligosaccharides du lait de Femme dont le taux varie entre 7 et 12 g p. litre.

Simultaneous Inhibition of Linolenic Acid Synthesis in Winter Wheat Roots and Frost Hardening by BASF 13-338, a Derivative of Pyridazinone

Treatment of 12-day-old winter wheat (Triticum aestivum) plants with BASF 13-338 {4-chloro-5 (dimethylamino)-2-phenyl-3(2H)-pyridazinone} 36 hours before frost hardening simultaneously and completely inhibits accumulation of linolenic acid in the roots during the hardening period and the acquisition of frost resistance. Increased unsaturation of fatty acids is therefore probably an important part of the mechanism of cold adaptation in winter wheat.BASF 13-338 also prevents the increase in per cent dry weight in roots and shoots during hardening and causes a decrease in root lipid phosphorus and total fatty acids.The concurrent increase in linoleic acid and decrease in linolenic acid in the treated plants, while the level of the other fatty acids is but little affected, suggest that BASF 13-338 specifically inhibits linoleic acid desaturase.