No abstract

Lotus glaber is a glycophytic, perennial legume from Europe that occurs widely in saline habitats. We evaluated the effect of mycorrhizal fungus colonization on the response to salt stress of two genotypes of L. glaber differing in their tolerance to salinity. The experiment consisted of a randomized block design with two factors: (1) mycorrhizal fungus treatments (with or without AM fungus) and (2) two salinity levels of 0 and 200 mM NaCl. Our results indicated that Glomus intraradices established a more efficient symbiosis with the tolerant than with the sensitive genotype. G. intraradices improved growth of L. glaber plants under saline conditions. They showed higher values of net growth, shoot/root and K + / Na + ratios, and protein concentrations than controls. Tolerant AM plants also showed higher chlorophyll levels than non-AM ones. Prevention of Na + accumulation in the plant and enhancement of K + concentrations in roots observed in this work could be part of the general mechanism of salt stress alleviation of L. glaber by G. intraradices.

To evaluate the importance of searching new naturally occurring strains to raise yields in mushroom production, eight wild and four commercial strains of Agrocybe cylindracea were cultivated on wheat straw. The highest biological efficiencies (BE) (54.5-72.4%) were obtained with three wild and two commercial strains when cultured on non-supplemented wheat straw. Rolled oats or soybean flour supplementation were tested using three selected strains, increasing BEs up to 1.2, 0.5 and 0.7-fold, respectively. This effect of supplementation was stronger in the Asiatic wild strain, yielding up to 41.1 and 30% more than the two other strains with rolled oats and soybean flour, respectively. The Asiatic wild strain cultivated with soybean flour supplementation achieved an average biological efficiency of 179%, to our knowledge, the highest reported for this species. These results show the importance of searching for new naturally occurring strains in combination with supplemented wheat straw substrate for raising yields in A. cylindracea cultivation.

Nomenclatural type definitions are one of the most important concepts in biological nomenclature. Being physical objects that can be re-studied by other researchers, types permanently link taxonomy (an artificial agreement to classify biological diversity) with nomenclature (an artificial agreement to name biological diversity). Two proposals to amend the International Code of Nomenclature for algae, fungi, and plants (ICN), allowing DNA sequences alone (of any region and extent) to serve as types of taxon names for voucherless fungi (mainly putative taxa from environmental DNA sequences), have been submitted to be voted on at the 11th International Mycological Congress (Puerto Rico, July 2018). We consider various genetic processes affecting the distribution of alleles among taxa and find that alleles may not consistently and uniquely represent the species within which they are contained. Should the proposals be accepted, the meaning of nomenclatural types would change in a fundamental way from physical objects as sources of data to the data themselves. Such changes are conducive to irreproducible science, the potential typification on artefactual data, and massive creation of names with low information content, ultimately causing nomenclatural instability and unnecessary work for future researchers that would stall future explorations of fungal diversity. We conclude that the acceptance of DNA sequences alone as types of names of taxa, under the terms used in the current proposals, is unnecessary and would not solve the problem of naming putative taxa known only from DNA sequences in a scientifically defensible way. As an alternative, we highlight the use of formulas for naming putative taxa (candidate taxa) that do not require any modification of the ICN.