Is Lotus zhegulensis Klok. (Fabaceae) a separate species endemic of the Middle Volga Region or just a variety of a widespread L. corniculatus L.?

We have studied several samples from Lotus corniculatus s. l. and L. zhegulensis populations with the use of SSR and sequenced nuclear (ITS) and plastid (atpB-rbcL, ndhC-trnV, rpl32-trnL(UAG), trnH-psbA, trnL-trnF) markers. We analysed 9 local populations from the Volga River valley ranging from Ulyanovsk in the north to Volgograd in the south, as well as two local populations from Moscow and Lipetsk Provinces. Analyses of SSR markers using the STRUCRURE program divided the sample into three genetic clusters. Populations from Moscow and Lipetsk Provinces, and three local populations from the ‘locus classicus’ location of L. zhegulensis in Samara Province appeared to be the most genetically differentiated while all the other populations were variously genetically admixed. Low pairwise Fst values indicate low genetic differentiation of Lotus populations and the intraspecific nature of the revealed diversity. The nuclear and plastid DNA sequences analyzed yielded little information. Substitutions and indels revealed were mostly autapomorphies characteristic of separate specimens or small groups of specimens but not of populations. Our study enables to firmly conclude that Lotus populations from the right bank of the Volga River in vicinity of Zhiguli upland described as L. zhegulensis are weakly genetically differentiated from other populations of Lotus corniculatus s. l. and, hence, cannot be regarded as a separate species.

Rendimiento de forraje de tres genotipos de Lotus corniculatus L., en función de la edad al corte

El objetivo fue determinar el efecto del momento del corte sobre la respuesta productiva de tres genotipos de L. corniculatus. El diseño fue completamente al azar, con tres repeticiones. El mayor y menor rendimiento se presentó a los 35 y 7 DDR con 5.48 y 0.72 g MS plant-1. La hoja fue la que más aportó al rendimiento. La mayor y menor relación hoja:tallo se registró a los 7 (5.71) y 42 DDR (2.39), siendo el genotipo 255301 superior al resto (p > 0.05). La altura y el peso del tallo se incrementaron de los 7 y 49 DDR. En conclusión, la edad de cosecha afectó a los genotipos de L. corniculatus, siendo mayor el 255301 al resto de los genotipos en la altura, relación hoja:tallo, y peso por tallo individual, no en rendimiento de forraje y composición botánica y morfológica.

The key regulator LcERF056 enhances salt tolerance by modulating reactive oxygen species-related genes in Lotus corniculatus

Background The APETALA2/ethylene response factor (AP2/ERF) family are important regulatory factors involved in plants’ response to environmental stimuli. However, their roles in salt tolerance in Lotus corniculatus remain unclear. Results Here, the key salt-responsive transcription factor LcERF056 was cloned and characterised. LcERF056 belonging to the B3–1 (IX) subfamily of ERFs was considerably upregulated by salt treatment. LcERF056-fused GFP was exclusively localised to nuclei. Furthermore, LcERF056- overexpression (OE) transgenic Arabidopsis and L. corniculatus lines exhibited significantly high tolerance to salt treatment compared with wild-type (WT) or RNA interference expression (RNAi) transgenic lines at the phenotypic and physiological levels. Transcriptome analysis of OE, RNAi, and WT lines showed that LcERF056 regulated the downstream genes involved in several metabolic pathways. Chromatin immunoprecipitation-quantitative polymerase chain reaction (ChIP-qPCR) and yeast one-hybrid (Y1H) assay demonstrated that LcERF056 could bind to cis-element GCC box or DRE of reactive oxygen species (ROS)-related genes such as lipid-transfer protein, peroxidase and ribosomal protein. Conclusion Our results suggested that the key regulator LcERF056 plays important roles in salt tolerance in L. corniculatus by modulating ROS-related genes. Therefore, it may be a useful target for engineering salt-tolerant L. corniculatus or other crops.

Componentes não constituintes da carcaça de borregos Corriedale brancos e naturalmente coloridos criados no Bioma Pampa

O trabalho foi conduzido com objetivo de verificar a influência do fenótipo nos componentes não constituintes da carcaça de borregos Corriedale, brancos e naturalmente coloridos. Foram utilizados 29 borregos, machos castrados, oriundos de parto simples, provenientes de dois fenótipos (13 naturalmente coloridos e 16 brancos), criados na região do Bioma Pampa, no Estado do Rio Grande do Sul, em condições extensivas de pastagem natural melhorada com azevém (Lolium multiflorum), cornichão (Lotus corniculatus) e trevo branco (Trifolium repens), e abatidos a idade média de 18 meses. Foram mensurados o peso corporal ao abate e o peso dos não constituintes da carcaça: baço, fígado com vesícula biliar, coração, pulmão com traqueia, rins com gordura perirrenal, vísceras verdes cheias (complexo gastrointestinal e conteúdo), pele, cabeça, patas, gordura interna e bexiga, calculando-se suas porcentagens em relação ao peso corporal ao abate. O efeito do fenótipo foi verificado através da análise de variância. Borregos Corriedale naturalmente coloridos foram mais pesados ao abate, com maior peso de pele, cabeça, baço e do conjunto pulmões com traqueia (P<0,05). Percentualmente, borregos Corriedale brancos apresentaram maiores valores para patas e bexiga (P<0,05). Conclui-se que borregos da raça Corriedale naturalmente coloridos, mantidos em condições extensivas de criação, sob campos do Bioma Pampa, são mais pesados ao abate e apresentam maior peso absoluto de alguns componentes corporais.

Persistencia de efectos a largo plazo de la fertilización fosfatada y la introducción de leguminosas en pastizales del Uruguay

En el campo natural (CN) de Uruguay la introducción de leguminosas con fertilización fosfatada (CN+LP) evita restricciones nutricionales, pero son poco conocidos sus efectos sobre el suelo y la pastura. Para evaluar estos efectos en el largo plazo se utilizó un experimento previo de introducción de Lotus corniculatus y fertilización fosfatada con un tratamiento testigo de CN (1995-2002). Entre 2013 y 2015 se determinó la producción primaria neta aérea (PPNA), contenido de nutrientes de la planta, composición y diversidad florística. En el suelo se analizó pH, contenido de C orgánico, P disponible y orgánico. En dos gramíneas nativas se evaluó la colonización micorrícica. El suelo CN+LP presentó mayor contenido de P disponible, pero no hubo diferencias en C orgánico. Aunque la PPNA fue similar, el contenido de P del forraje fue mayor en CN+LP respecto a CN, mientras que la micorrización fue mayor en CN. La composición florística y la diversidad no difirieron. Se concluye que, aunque no se mantuvieron las ventajas productivas de CN+LP en PPNA, hubo una mejora en la calidad del forraje debido a su mayor contenido de P. Sin embargo, no hubo efectos en servicios ecosistémicos claves como la diversidad de especies.

Introduction of H2-Uptake Hydrogenase Genes Into Rhizobial Strains Improves Symbiotic Nitrogen Fixation in Vicia sativa and Lotus corniculatus Forage Legumes

Biological nitrogen fixation by the Rhizobium-legume symbiosis allows the conversion of atmospheric nitrogen into ammonia within root nodules mediated by the nitrogenase enzyme. Nitrogenase activity results in the evolution of hydrogen as a result of a side reaction intrinsic to the activity of this enzyme. Some rhizobia, and also other nitrogen fixers, induce a NiFe uptake hydrogenase (Hup) to recycle hydrogen produced by nitrogenase, thus improving the efficiency of the nitrogen fixation process. In this work we report the generation and symbiotic behavior of hydrogenase-positive Rhizobium leguminosarum and Mesorhizobium loti strains effective in vetch (Vicia sativa) and birsfoot trefoil (Lotus corniculatus) forage crops, respectively. The ability of hydrogen recycling was transferred to these strains through the incorporation of hup minitransposon TnHB100, thus leading to full recycling of hydrogen in nodules. Inoculation of Vicia and Lotus plants with these engineered strains led to significant increases in the levels of nitrogen incorporated into the host legumes. The level of improvement of symbiotic performance was dependent on the recipient strain and also on the legume host. These results indicate that hydrogen recycling has the potential to improve symbiotic nitrogen fixation in forage plants.