Plant regeneration from cotyledonary tissue of Glycine canescens,a perennial wild relative of soybean

Cotyledonary tissue from immature embryos of Glycine canescens was induced to callus and then form embryo-like structures. These structures could be cultured into whole plants and grown in soil.     

Changes in cell-wall polysaccharides in relation to seedling development and the mobilisation of reserves in the cotyledons of Lupinus angustifolius cv. Unicrop

Some 22% of the dry weight of the cotyledons of resting seeds of Lupinus angustifolius cv. Unicrop has been shown to be non-starch polysaccharide material comprising the massively thickened walls of the storage mesophyll cells. On hydrolysis this material released galactose (76%), arabinose (13%), xylose (4%), uronic acid (7%): only traces of glucose were detected indicating the virtual absence of cellulose from the walls. Changes in the amount and composition of this material following germination have been studied in relation to parameters of seedling development and the mobilisation of protein, lipid and oligosaccharide reserves. Starch, which was not present in the resting seed, appeared transitorily following germination: under conditions of continuous darkness starch levels were reduced. During the period of bulk-reserve mobilisation, 92% of the non-starch polysaccharide material disappeared from the cotyledons. The residual cell-wall material released galactose (14%), arabinose (19%), xylose (24%) and uronic acid (43%). The galactose and arabinose residues of the cotyledonary cell walls clearly constitute a major storage material, quantitatively as important as protein. The overall role of the wall polysaccharides in seedling development is discussed.     

Catecholamines in fetal pig plasma and the response to acute hypoxia and chronic fetal decapitation

Summary Dopamine, norepinephrine and epinephrine were measured by radioenzymatic assay in blood plasma samples drawn from the umbilical arteries of 30 anaesthetised Landrace pig fetuses. Just prior to term, the concentrations of dopamine (0.46±0.14 ng·ml^–1) and norepinephrine (1.74±0.60 ng·mg^–1) were lower than earlier in gestation, whereas epinephrine concentrations at term (0.80±0.31 ng·ml^–1) were similar to those at mid-gestation, intervening stages of gestation having higher levels of plasma epinephrine. Fetal hypoxia was induced by clamping the umbilical cord for 2 min and the catecholamines determined in arterial blood samples immediately thereafter, then again 3 min after removal of the clamp. Inconsistent effects of cord clamping on catecholamine levels were seen at 55 days, but thereafter, in all but one instance, the hormone levels were increased. Fetuses near term tended to respond less than fetuses at 75 and 96 days gestation (term=114±1 day). Catecholamines were also present in the circulation of fetuses decapitated at 42 days gestation and studied at 109±1 days. The average concentrations of dopamine (1.12±0.27 ng·ml^–1) and norepinephrine (8.23±3.04 ng·ml^–1) were greater than in intact fetuses, the plasma epinephrine levels being comparable to, or slightly higher than, those in intact fetuses. The results demonstrate that catecholamines are present in the circulation of the intact and decapitated pig fetus and that the actual concentrations and the type of response to umbilical cord clamping are dependent on gestation age.     

Selected aspects of collared peccary (Dicotyles tajacu) reproductive biology in a captive texas herd

Collared peccaries (Dicotyles tajacu) from 32 litters were born in captivity during the period from September, 1981 through July, 1983. Incidence of singleton, twin, and triplet litters was 28%, 66%, and 6%, respectively. Mean (± SE) weight of young from singleton, twin, and triplet litters was 751 (± 35) gm, 698 (± 17) gm, and 612 (± 74) gm, respectively. Sex ratio among all litters was 56:44 (M:F). Neonatal mortality amounted to 9% of the young born. Mean duration of estrus was 2.60 days and mean length of gestation was 145.6 days. Evidence indicated that multiple copulations increased ovulation rate and the chance for conception.     

Duration of Hydrogen Formation by Anabaena cylindrica B629 in Atmospheres of Argon, Air, and Nitrogen

The time course of hydrogen formation by Anabaena cylindrica was followed beneath an argon atmosphere alone and also beneath atmospheres of argon, nitrogen, and air in the presence of carbon monoxide (0.2%) and acetylene (5%). Hydrogen production beneath argon alone was comparable in rate and duration (7 to 12 days) to that which occurred beneath air in the presence of carbon monoxide (0.2%) and acetylene (5%). However, much greater longevity (16 to 26 days) and improved rates of hydrogen formation were obtained when algae were incubated beneath argon and particularly nitrogen, each supplemented with carbon monoxide and acetylene. The total hydrogen produced by these cultures was up to three times as much as that released by cultures incubated beneath argon alone. Hydrogen-oxygen ratios for argon cultures either with or without carbon monoxide and acetylene were initially 1:5 but approximated 1:2 when measured over the entire incubation period. In each case oxygen production and nitrogenase activity (acetylene reduction) continued at reduced rates after hydrogen evolution had ceased. The effects of methionine sulfoximine (2 μM), ammonium ions (0.5 mM), or both on oxygen production were generally negligible, while effects on hydrogen production were variable depending on the atmosphere used; in most cases, eventual destabilization of the system occurred. A brief comparison was made of the time courses of anaerobic and aerobic hydrogen formation by the marine cyanobacterium Calothrix membranacea. It was found that shaking of cultures was beneficial for hydrogen production but not strictly necessary. It is concluded that hydrogen production by A. cylindrica in air and particularly nitrogen in the presence of carbon monoxide and acetylene offers the best potential of the atmospheres considered on the basis of four criteria: rates and longevity of hydrogen formation, practicality of the atmosphere used, and tolerance of hydrogen evolution to slight changes in composition of the atmosphere.     

An investigation into the mechanism for reduced seed yield inLotus corniculatus

Summary A study of seed position in the pod ofLotus corniculatus L. cv. Mirabel (Fabaceae) suggested that reduced seed set after self-pollination is not due to an inability of the self-pollen tube to reach the end of the ovary. As in other cultivars, it has been demonstrated that cultivar Mirabel produced less seed per pod and shorter pods after self- than after cross-pollination. No differences were noted for percent germination of seeds produced by both types of pollination indicating that the number of seeds per pod is a reliable index of the ultimate productive potential of the pollination.     

Histamine-releasing activity (HRA). I. Production by mitogen- or antigen-stimulated human mononuclear cells.

Supernatants from 1- to 2-day cultures of human mononuclear cells induced the release of histamine from basophils. Generation of this histamine-releasing activity (HRA) was stimulated by addition of concanavalin A to the cell cultures. Mononuclear cells were also cultured with SKSD and Candida albicans antigens. Stimulation of HRA production by these antigens was correlated with positive delayed skin reactions. Serial dilutions of supernatants assayed for HRA provided a semiquantitative determination of the level of HRA in mitogen- or antigen-stimulated samples. Antigen increased HRA production when added during the first or second day of culture. Generation of HRA probably requires active protein synthesis, since puromycin was inhibitory, and since preformed HRA could not be recovered from lysed cells. HRA was detected in supernatants after 4 hr, and the effects of antigen stimulation were apparent after 8 hr of culture. Replacement of supernatants with fresh culture medium allowed continued synthesis of substantial quantities of HRA during the second day of culture. A linear correlation was observed between the amount of HRA produced and the mononuclear cell concentration. Our findings provide evidence for the interaction of lymphocytes and basophils via a soluble mediator.