The anal gland secretion of the European badger (Meles meles) and its role in social communication

The aim of this study was to investigate the chemical profile and hence the potential biological function of anal gland secretion in the European badger ( Meles meles ). Samples of secretion collected from wild and captive animals were analysed using gas chromatography. Analysis of whole secretion revealed the scent profiles of all samples to be remarkably similar. No evidence was found to suggest that the secretion contained information about the individual identity or sex of its producer, although some evidence was found of group differences in odour profile. Analysis of methylated samples revealed the secretion to be of low volatility, containing a number of long-chain (> C14) fatty acids, 15 of which were identified. The results are consistent with the idea that badger anal gland secretion functions as a long-term territory marker.     

The Effects of Mechanical Impedance to Growth on the Levels of ABA and IAA in Root Tips of Zea mays L.

Extraction and analytical methods have been refined and newones devised to allow precise determinations by GC-EC of thelevels of abscisic acid (ABA) and indol-3ylacetic acid (IAA)in samples of maize root tips as small as 1.0 g fr. wt. Seminalroots of 5-d-old maize seedlings grown in normal (bulk density1200 kg m^–3) and compacted (bulk density 1600 kg m^–3)sand/garden loam mixtures have been examined. Seminal rootsfrom compacted soil had an average length of about 40% of thatof control roots and were much thicker. The ABA levels in 10mm tips of impeded roots (c. 25–35 ng g^–1 fr.wt.)did not differ significantly from those of normal root tipson both a fresh and dry weight basis. The levels in 0–1mm tips were approximately double those in the remaining 1–10mm zones. IAA levels were increased by about 3 times in impededroots (176.3 as compared with 52.4 ng g^–1 fr.wt) and itis concluded that this response is likely to be the main causeof the morphological and growth changes brought about by soilcompaction.     

Salt Tolerance in the Halophyte Suaeda maritima L.Dum.: Abscisic Acid Concentrations in Response to Constant and Altered Salinity

Endogenous abscisic acid contents were measured by gas-liquidchromatography in shoots of Suaeda maritima growing both inthe steady state over a range of salinities and over a time-coursefollowing an increase in the culture solution salinity of betweenapproximately 100 and 400 mol m^–3 NaCl. In steady-stateplants, the ABA content was maximal in the absence of salt at41 ng g^–1 fr. wt., declining to a minimum at 200 mol m^–3NaCl of 24 ng g^–1 fr. wt. Increase of culture solutionsalinity resulted in a marked increase in shoot ABA which wasmaximal after 6 h or 24 h in plants previously growing at 200mol m^–3 NaCl and in the absence of salt, respectively.Additionally, culture solution water potentials were loweredby 1.0 MPa (equivalent to raising the salt concentration byaround 200 mol m^–3); this resulted in a similar increasein endogenous ABA content to that brought about by an iso-osmoticsalt increase. Results are discussed in relation to the possiblerole of ABA in halophyte salt tolerance mechanisms. Key words: Suaeda, halophyte, abscisic acid, salt tolerance     

The Use of 14C-Ethane Diol as a Quantitative Tracer for the Transpirational Volume Flow of Water and an Investigation of the Effects of Salinity upon Transpiration, Net Sodium Accumulation and Endogenous ABA in Individual Leaves of Oryza sativa L.

Yeo, A. R., Yeo, M. E., Caporn, S. J. M., Lachno, D. R. andFlowers, T. J. 1985. The use of ¹⁴C-ethane diol as a quantitativetracer for the transpirational volume flow of water and an investigationof the effects of salinity upon transpiration, net sodium accumulationand endogenous ABA in individual leaves of Oryza sativa L.—J.exp. Bot. 36: 1099–1109. Oryza sativa L. (rice) seedlings growing in saline conditionsexhibit pronounced gradients in leaf sodium concentration whichis always higher in the older leaves than the younger ones.Individual leaf transpiration rates have been investigated todiscover whether movement of sodium in the transpiration streamis able to explain these profiles from leaf to leaf. The useof ¹⁴C labelled ethane diol to estimate transpiration was evaluatedby direct comparison with values obtained by gas exchange measurements.Ethane diol uptake was linearly related to the transpirationalvolume flow and accurately predicted leaf to leaf gradientsin transpiration rate in saline and non-saline conditions. ¹⁴C-ethanediol and ²²NaCl were used to compare the fluxes of water andsodium into different leaves. The youngest leaf showed the highesttranspiration rate but the lowest Na accumulation in salineconditions; conversely, the older leaves showed the lower transpirationrates but the greater accumulation of Na. The apparent concentrationof Na in the xylem stream was 44 times lower into the youngerleaf 4 than into the older leaf 1. Exposure to NaCl (50 molm^–3) for 24 h elicited an increase in endogenous ABA inthe oldest leaf only, but no significant changes occurred inthe younger leaves. Key words: —Salinity, rice, Oryza sativa L., transpiration, volume flow, abscisic acid