Taxonomy and evolution of cultivated plants: Literature review 1983/1984

Summary Important papers on taxonomy and evolution of cultivated plants published in 1983 and 1984 were complied and briefly discussed.

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Taxonomie und Evolution der Kulturpflanzen: Literaturübersicht 1983/1984

Zusammenfassung Wichtige Arbeiten über Taxonomie und Evolution der Kulturpflanzen aus den Jahren 1983 und 1984 wurden zusammengestellt und kurz kommentiert.

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: 1983–1984

, 1983 1984 . .

     

Report of a collecting mission to the Georgian SSR 1983 for the study of indigenous material of cultivated plants

Summary In the summer 1983 the joint activities for the collection of autochthonous material of cultivated plants have been continued in the outermost western regions of Georgia (Abkhazia, Megrelia). Altogether 434 accessions could be obtained, more than one third of them being grain legumes, and one fourth vegetables and spice plants, resp. The remaining part includes mainly maize. Gene-erosion is very advanced especially for cereals and some grain legumes besidesPhaseolus vulgaris for which an astonishing genetic variability could be confirmed within the local material. Some details of the accessions regarding botanical interest and breeding value have been outlined. The collecting work should be continued.

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Bericht über eine Reise in die Georgische SSR 1983 zur Sammlung indigenen Materials von Kulturpflanzen

Zusammenfassung Im Sommer 1983 wurde eine weitere gemeinsame Reise zur Sammlung autochthonen Kulturpflanzenmaterials unternommen, die in die westlichen Teile von West-Georgien (Abchasien, Megrelien) führte. Es konnten insgesamt 434 Proben gesammelt werden, von denen mehr als ein Drittel Körnerleguminosen und je etwa ein Viertel Gemüse- und Gewürzpflanzen waren. Getreide war fast ausschließlich durch Mais vertreten. Die Gen-Erosion ist bei Getreide und einigen Körnerleguminosen bereits sehr weit fortgeschritten, während beiPhaseolus vulgaris wiederum eine erstaunliche Vielfalt an Formen festgestellt werden konnte. Besonders interessantes Material von Knoblauch, Blattkohlformen und einigen Spinatgemüsen wird kurz vorgestellt. Die Sammeltätigkeit sollte fortgesetzt werden.

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1983 .

1983 . ¶rt; , (, ). 434 , , . . , . , «» . .

     

Oberflächenstrukturen und Eigenschaften von Permafrostböden im nordsibirischen Lena-Delta

Patterned ground and properties of permafrost soils of the Northsiberian Lena Delta The land surface of the Lena Delta is covered by polygon structures with scattered pingos and dunes. There exist so-called aerated, swampy and open polygons (open water surface) with Gelic Gleysols and Gelic Histosols (gelundic phase). The soils show only minor signs of cryoturbation and weathering. They contain high amounts of silt and slightly decomposed organic matter down to soil depths far beyond the permafrost table during summer. The soil surface is rising due to accumulation of organic matter and periodic flooding. This leads to a continuous rise of the permafrost table and subsequently to a permafrost freeze storage of plant material. The soils are therefore effective carbon sinks. On top of an investigated pingo a Gleyi-gelic Cambisol developed due to windexposed position, good drainage and higher soil temperatures connnected with a deeper permafrost table. This soil did not show any signs of cryoturbation. It has a relatively low content of organic matter due to a higher mineralization. As a consequence of frost effected sorting and wind erosion the soil material near to the surface is rich in sand and has a reduced silt content.     

Chromatographische Trennung von teerbürtigen PAK in einem Boden

Chromatographic separation of tarborne PAH in a soil At coal gas production sites soils are frequently infiltrated by fluid coal tar. From tar-filled pores a further diffusive and/or convective dispersion of PAH into the soil matrix occurs. Results from a contaminated site indicate, that the systematic change of the PAH congener pattern along the transport vector is due to differences in solubility and adsorption. This leads to a chromatographic fractionation of the initial PAH mixture with the least adsorbed congeneres forming the front of PAH translocation and the strongest adsorbed congeneres moving clearly slower.     

Taxonomic status and geographic provenance of germplasm accessions in the Solanum nigrum L. complex: AFLP data

Amplified Fragment Length Polymorphisms (AFLPs) were employed within the taxonomically difficult Solanum nigrum L. complex in order to characterize the genetic diversity present in a collection of the Gatersleben Genebank, to classify taxonomically unknown material, and to correlate the clustering of the examined accessions with their geographic origin. The results from AFLP analyses using two primer combinations on 44 entries from five species led to the detection of four major clusters, simultaneously uncovering significant differences in the levels of genetic diversity within or between species. S. americanumexhibited the highest infraspecific variation despite close geographic origins, simultaneously being placed in a clearly separated cluster in comparison to the other examined species of the complex. In addition, these other species showed even less interspecific variation than was found at the infraspecific level in S. americanum. In terms of taxonomy, the application of AFLPs helped in the classification of 13 black nightshade accessions formerly only listed as Solanum sp. This also was confirmed by morphological determination. Furthermore, one accession formerly classified as S. physalifolium var. nitidibaccatum i) clustered with AFLPs and ii) was identified morphologically as S. villosum. Contradictory classifications remain for two further entries from the same species, found within the S. nigrum cluster after AFLP analyses, while belonging to S. physalifolium var. nitidibaccatum according to herbarium specimen. Finally, as indicated by the information on provenance in geographically separated subclusters in S. americanum and partially in S. villosum, clues on the currently unknown origin of accessions from the genebank seem feasible by AFLP data.     

Irrigation with plant extracts in ecofarming increases biomass production and mineral and organic nitrogen content of plants

Seedlings of alfalfa, rape, spinach, and wheat, potted on sandy soil, were irrigated with an aqueous extract of pea shoot (PE, 9.84 g dry weight l^–1) or a solution of Ca, K, Mg, P, and NO₃‐N salts (SS) in a concentration similar to that in PE, for 31–48 days. In comparison to water‐irrigated controls, both SS and PE treated plants showed nearly equal increases in shoot dry weight (29–40 %), whereas PE‐treated plants had higher fresh weights (38–84 %) due to increased succulence. Treatment with SS did not enhance, but sometimes even reduce, the concentrations of Ca, K, Mg, and several trace elements in shoot tissues. In contrast, PE‐treated plants had higher Ca, K, Mg, and organic N, but lower As and Ni contents and were thus of higher nutritive value. Reduced contents of metals in plant tissue correlated with their reduced solubility in the soil solution, which was not due to changes in pH. Fertilizer components such as K and Mg (metals of lower exchange intensity) were incorporated into the soil to release Ca, Sr, and Ba (metals of higher exchange intensity) and reduce the solubility of most trace elements and metal‐complexing humic substances. In addition, application of Ca precipitated heavy metals and humic complexes directly from the soil solution. This effect was partially overcome by PE. Its carboxylic acids could act as phytochelators of metal ions and as mobilizers of the highly diffusible humic substances which carry metals to roots. It is concluded that continuous PE application replaces the quantities of Ca, K, Mg, P, and organic N, but not of NO₃‐N consumed during plant growth. Using PE does not add any relevant quantities of toxic metals to the plant‐soil system.     

Effects of the aglycone of ascaulitoxin on amino acid metabolism in Lemna paucicostata

Ascaulitoxin and its aglycone (2,4,7-triamino-5-hydroxyoctanoic acid, CAS 212268-55-8) are potent phytotoxins produced by Ascochyta caulina, a plant pathogen being developed for biocontrol of weeds. The mode of action of this non-protein amino acid was studied on Lemna paucicostata. Ascaulitoxin is a potent growth inhibitor, with an I₅₀ for growth of less than 1 μM, almost completely inhibiting growth at about 3 μM. Its action is slow, starting with growth inhibition, followed by darker green fronds, and then chlorosis and death. Most amino acids, including non-toxic non-protein amino acids, reversed the effect of the toxin when supplemented in the same medium. Supplemental sucrose slightly increased the activity. d-Amino acids were equally good inhibitors of ascaulitoxin activity, indicating the amino acid effects may not be due to inhibition of amino acid synthesis. Oxaloacetate, the immediate precursor of aspartate, also reversed the activity. LC-MS did not detect interaction of the compound with lysine, an amino acid that strongly reversed the effect of the phytotoxin. Metabolite profiling revealed that the toxin caused distinct changes in amino acids. Reduction in alanine, paralleled by enhanced levels of the branched chain amino acids valine, leucine and isoleucine and nearly unchanged levels of pyruvate, might indicate that the conversion of pyruvate to alanine is affected by ascaulitoxin aglycone. In addition, reduced levels of glutamate/glutamine and aspartate/asparagine might suggest that synthesis and interconversion reactions of these amino group donors are affected. However, neither alanine aminotransferase nor alanine: glyoxylate aminotransferase were inhibited by the toxin in vitro. Our observations might be explained by three hypotheses: (1) the toxin inhibits one or more aminotransferases not examined, (2) ascaulitoxin aglycone affects amino acid transporters, (3) ascaulitoxin aglycone is a protoxin that is converted in vivo to an aminotransferase inhibitor.