The effect of monochromatic radiation in the range 350 to 750 nm on the carotenogenesis in Verticillium agaricinum

An action spectrum for carotenogenesis in V. agaricinum has maxima at 395, 433, 660 and 737 nm. In a previous study it had been shown that a light-minus-dark difference spectrum of a crude extract from V. agaricinum had maxima at 390 and 420 nm, and furthermore a red, far-red interaction suggesting phytochrome involvement has been proposed. All these data suggest that there may be at least two photoreceptor systems operating in the photoinduction process here; one for the near-ultraviolet (UV-A)-mediated carotenogenesis, presumably a novel pigment, and the other for the red, far-red region, most likely phytochrome.     

Ploidy and strain differences in seed germination of Glycine wightii at different pH levels

Summary Seeds from 27 wild strains (18 tetraploids and 9 diploids) of Glycine weightii were germinated at a pH range of 5 to 8. The differences in germination (%) between all the strains were highly significant but between pH levels they were only nearly significant (P=0.067) with no interaction between pH levels and strains. Mean germination (%) for all tetraploids seems to be slightly higher ( 2%) than that for all diploids, especially at pH's 5, 7 and 8 but this may be due to the significantly longer time ( one day) it took tetraploids to complete germination. The apparent inverse relationship between seed weight and germination (%) was not significant.Mean germination time was highly significant for strains, pH's and their interaction. Increasing mean germination (%) resulted in decreasing mean germination time among strains. Large seeds took less time to germinate especially those from some of the tetraploid strains. This indicates that it is possible to produce a variety with high germination (%), fast germination rate and possibly large seeds. If the marked difference in pH tolerance among strains will prove to be mainly hereditary, then it will be also possible to select for either specific pH tolerance or tolerance at a wide range of pH.     

Produits neutres et alcaloides de Myrtopsis macrocarpa,M. myrtoidea,M. novae-caledoniae et M. sellingii

Stems and leaves of Myrtopsis macrocarpa, M. myrtoidea, M. novae-caledoniae and M. sellingii yielded terpenes, sterols, coumarins, alkaloids (furoquinolines and quinolones) and amides. A new quinolone (8-methoxy flindersine) occurs in Myrtopsis macrocarpa, a new amide (N-benzoyltryptamine) in M. myrtoidea, two new coumarins (myrsellin and myrsellinol) and a new dihydrofuroquinoline (myrtopsine) in M. sellingii. Structures of the new compounds are proposed from chemical and spectroscopic evidence.     

Cowpea Rhizobia Producing Dark Nodules: Use in Competition Studies

During a program of screening rhizobia from West Africa, it was found that some strains produced nodules of unusually dark appearance on cowpeas, but not on peanuts, soybeans, pigeon peas, or mung beans. The dark pigmentation was in the bacteroid zone, was not correlated with nodule effectiveness, and was additional to the leghemoglobin pigment. Only rhizobial strains with a nongummy (“dry”) colony morphology produced dark nodules. Visually distinguishable pink and dark nodules formed on the same root when a mixture of pink and dark strains was applied as inoculum. The dark-nodule phenotype was therefore appraised as a marker and found to be useful for studying nodulation competition with strains of the orthodox pink-nodule type. The competitiveness of 10 pink-nodule strains was examined relative to a black-nodule strain, IRc 256; a range of competitiveness was obtained of less competitive than, equally competitive to, or more competitive than IRc 256. Patterns of primary (early) nodulation were generally the same as patterns of secondary (later) nodulation. Mixed infections by dark and pink strains produced piebald nodules, the frequency of occurrence of which was much greater among primary than among secondary nodules.     

Studies on dehydro-l-ascorbic acid 2-arylhydrazone 3-oximes: Conversion into substituted triazoles and isoxazolines

l-threo-2,3-Hexodiulosono-1,4-lactone 2-(arylhydrazones) (2) were prepared by condensation of dehydro-l-ascorbic acid with various arylhydrazines. Reaction of 2 with hydroxylamine gave the 2-(arylhydrazone) 3-oximes (3). On boiling with acetic anhydride, 3 gave 2-aryl-4-(2,3-di-O-acetyl-l-threo-glycerol-l-yl)-1,2,3-triazole-5-carboxylic acid 5,4¹-lactones (4). On treatment of 4 with liquid ammonia, 2-aryl-4-(l-threo-glycerol-l-yl)-1,2,3-triazole-5-carboxamides (5) were obtained. Acetylation of 5 with acetic anhydride-pyridine gave the triacetates, and vigorous acetylation with boiling acetic anhydride gave the tetraacetyl derivatives. Periodate oxidation of 5 gave the 2-aryl-4-formyl-1,2,3-triazole-5-carboxamides (8), and, on reduction, 8 gave the 2-aryl-4-(hydroxymethyl)-1,2,3-triazole-5-carboxamides, characterized as the monoacetates and diacetates. Controlled reaction of 2 with sodium hydroxide, followed by neutralization, gave 3-(l-threo-glycerol-l-yl)-4,5-isoxazolinedione 4-(arylhydrazones), characterized by their triacetates. Reaction of 2 with HBr-HOAc gave 5-O-acetyl-6-bromo-6-deoxy-l-threo-2,3-hexodiulosono-1,4-lactone 2-(arylhydrazones); these were converted into 4-(2-O-acetyl-3-bromo-3-deoxy-l-threo-glycerol-l-yl)-2-aryl-1,2,3-triazole-5-carboxylic acid 5,4¹-lactones on treatment with acetic anhydride-pyridine.     

The polysaccharides of the brown seaweed Turbinaria murrayana

Polysaccharides of the brown seaweed Turbinaria murrayana were isolated. Laminaran (3.2%) was isolated from the hot-water extract of the algae by using ion-exchange chromatography. Fucans (2.1%) were isolated from the hot-water extract, as well (4.7%) as from the extract of the algae with dilute acid. Acid hydrolsysis of the isolated fucans revealed glucose, amnnose, fucose, glucuronic acid, xylose, and galactose. Alginic acid (22.6%) was separated, and reduced to a neutral polysaccharide. The polysaccharides isolated were analyzed by methylation and Smith degradation.     

13C isotope discrimination correlates with biological nitrogen fixation in soybean (Glycine max (L.) Merrill)

Ammonium sulphate was applied at the rate of 300 kg N ha^–1 with or without the nitrification inhibitor 1-carbamoyl-3(5)-methylpyrazol (4 kg ha^–1) to plots measuring 1.5 × 1.5 m. The fertilizer and the inhibitor were washed into the top 15-cm layer of the soil, which was highly calcareous (55% CaCO₃), and the plots were kept bare. The process of nitrification was monitored by regular soil sampling. In the absence of the inhibitor, nitrification was completed in three weeks. In the presence of the inhibitor only 10% of applied N was nitrified by the end of the third week and 42% by the end of the eighth week. Average soil temperature at 5–, 10– and 20-cm depth over the first six weeks was 26.0, 24.8 and 24.2°C, respectively.     

Carbon isotope discrimination at vegetative stage as an indicator of yield and water use efficiency of spring wheat (Triticum turgidum L. var. durum)

A field experiment was conducted to investigate if carbon isotope (¹³C) discrimination () measured at the vegetative stage of spring wheat (Triticum turgidum L. var. durum) is related with the yield and water use efficiency (WUE) at ripening. A line source sprinkler irrigation system exposed the wheat genotypes to different watering regimes, from rainfed to full irrigation and thereby increased the range in yield and WUE attainable in the four genotypes studied. The results indicated that values measured at the late stem elongation stage 60 days after planting (DAP), showed strong positive correlation with total dry matter yield (r=0.732^***), and a highly significant negative correlation with WUE (r=–0.755^***) measured at ripening 105 DAP. The data suggest that the imprints of measured at vegetative growth stage persists throughout the entire growth period, until maturity. Subject to confirmation from additional studies in other crops and locations, early measurements of may prove a useful tool for rapid and early screening of cultivars, for high yield and high WUE.     

Effect of cyclic AMP on fructose utilization, progressive motility and protein synthesis by ram spermatozoa

Ejaculated washed ram spermatozoa showed consistent increases in the intracellular concentration of cyclic 3', 5'-adenosine monophosphate (cAMP) after incubation for 15 minutes with the phosphodiesterase (PDE)-inhibitors, theophylline and caffeine. In vitro addition of cAMP or PDE-inhibitors to ram semen also stimulated and maintained sperm motility and enhanced the rate of fructose utilization. The same doses of cAMP or theophylline significantly stimulated the rate of protein synthesis by the washed spermatozoa, while the PDE-stimulator, imidazole, inhibited protein synthesis significantly. The stimulatory effect of cAMP on sperm protein synthesis was not affected by cycloheximide, but was abolished by the mitochondrial inhibitor, chloramphenicol. The present results indicate a positive correlation between the intracellular concentration of cAMP and the rates of progressive motility, fructose utilization, and protein synthesis by ram spermatozoa. The results suggest that the effect of cAMP is associated with the synthesis of mitochndrial proteins which may be involved with the observed enhancement of sperm motility and metabolism. The data also indicate that cAMP map act either as a first or a second messenger in mature spermatoza.     

Human and rat chromosomal localization of two genes for 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase by analysis of somatic cell hybrids and in situ hybridization

Two genes encoding 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase were localized in human and rat chromosomes. PFKFB1 (previously PFRX), which encodes the liver and muscle isozymes, was assigned to Xq22-q31 in the rat and to Xq27–q28 in the human by in situ hybridization using probes generated by the polymerase chain reaction. PFKFB2, which encodes the heart isozyme of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase, was assigned to chromosome 13 in the rat and to chromosome 1 in the human by hybridization of DNA from somatic cell hybrids. By in situ hybridization, this gene was localized to the regions 13q24–25 in the rat and 1q31 in the human.