The Harvest Index as Breeding Criteria in Soybean [Glycine max (L.) Merrill]

Crosses of soybean genotypes (cv. Atlanta, MG 0; cv. Romantica, MG 00; cv. Izidor, MG I and cv. Houta, MG I) with different meaning of the trait harvest index (HI) were made (2017) and studied (2018-2020) in the environmental conditions of the region of Central North Bulgaria, the town of Pavlikeni (43°24\u27 N, 25°32\u27 E, 144 m a.s.l.). The objectives of the study were: i) establishment of genotype variance by HI and the traits determined for it in the group of the parent genotypes and in their hybrid populations (F2-F3 generations); ii) assessment of the potential of different parent genotypes and development of the strategy for crosses for the improvement of the HI; iii) assessment of the capacity of the HI as main or additional selection criteria in the breeding programs for seed productivity of soybean. In F2 and F3 generation of each hybrid combination biometrical and variance analyses were conducted for the following traits: total yield of aboveground plant biomass (including seeds, stems and branches, without leaves -BMY, g); seed yield per plant (SY, g) and harvest index (HI). The correlation (r) and regression (b) between F2 and F3 were assessed on the base of the middle values in F3 generation of each hybrid combination and its corresponding individual values per transgressive forms in HI. Based on the results obtained, the application of father component with high meaning of the HI resulted in breeding progress for seed productivity. It is reasonable to use the application of the harvest index as a breeding criterion in progenies of the crosses with father genotype as a donor with high value of the trait aboveground biomass. By phenotypic assessment of the HI as additional selection criteria recombinant lines with increased seed productivity were selected

Recent Progress in Development of Tnt1 Functional Genomics Platform for Medicago truncatula and Lotus japonicus in Bulgaria

Legumes, as protein-rich crops, are widely used for human food, animal feed and vegetable oil production. Over the past decade, two legume species, Medicago truncatula and Lotus japonicus, have been adopted as model legumes for genomics and physiological studies. The tobacco transposable element, Tnt1, is a powerful tool for insertional mutagenesis and gene inactivation in plants. A large collection of Tnt1-tagged lines of M. truncatula cv. Jemalong was generated during the course of the project ‘GLIP’: Grain Legumes Integrated Project, funded by the European Union (www.eugrainlegumes.org). In the project ‘IFCOSMO’: Integrated Functional and COmparative genomics Studies on the MOdel Legumes Medicago truncatula and Lotus japonicus, supported by a grant from the Ministry of Education, Youth and Science, Bulgaria, these lines are used for development of functional genomics platform of legumes in Bulgaria. This review presents recent advances in the evaluation of the M. truncatula Tnt1 mutant collection and outlines the steps that are taken in using the Tnt1-tagging for generation of a mutant collection of the second model legume L. japonicus. Both collections will provide a number of legume-specific mutants and serve as a resource for functional and comparative genomics research on legumes. Genomics technologies are expected to advance genetics and breeding of important legume crops (pea, faba bean, alfalfa and clover) in Bulgaria and worldwide

Expanding the Benefits of Tnt1 for the Identification of Dominant Mutations in Polyploid Crops: A Single Allelic Mutation in the MsNAC39 Gene Produces Multifoliated Alfalfa

Most major crops are polyploid species and the production of genetically engineered cultivars normally requires the introgression of transgenic or gene-edited traits into elite germplasm. Thus, a main goal of plant research is the search of systems to identify dominant mutations. In this article, we show that the Tnt1 element can be used to identify dominant mutations in allogamous tetraploid cultivated alfalfa. Specifically, we show that a single allelic mutation in the MsNAC39 gene produces multifoliate leaves (mfl) alfalfa plants, a pivot trait of breeding programs of this forage species. Finally, we discuss the potential application of a combination of preliminary screening of beneficial dominant mutants using Tnt1 mutant libraries and genome editing via the CRISPR/Cas9 system to identify target genes and to rapidly improve both autogamous and allogamous polyploid crops.Fil: Jozefkowicz, Cintia. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Gómez, Cristina. Agencia de Extension Rural Villa Maria (aer Villa Maria) ; Estacion Experimental Agropecuaria Manfredi ; Centro Regional Cordoba ; Instituto Nacional de Tecnologia Agropecuaria;Fil: Odorizzi, Ariel Sebastian. Agencia de Extension Rural Villa Maria (aer Villa Maria) ; Estacion Experimental Agropecuaria Manfredi ; Centro Regional Cordoba ; Instituto Nacional de Tecnologia Agropecuaria;Fil: Iantcheva, Anelia. AgroBioInstitute Agricultural Academy; BulgariaFil: Ratet, Pascal. Université D'evry Val D'essonne; Francia. Centre National de la Recherche Scientifique; FranciaFil: Ayub, Nicolás. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; ArgentinaFil: Soto, Gabriela Cynthia. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; Argentin

The Arabidopsis thaliana checkpoint kinase WEE1 protects against premature vascular differentiation during replication stress

A sessile lifestyle forces plants to respond promptly to factors that affect their genomic integrity. Therefore, plants have developed checkpoint mechanisms to arrest cell cycle progression upon the occurrence of DNA stress, allowing the DNA to be repaired before onset of division. Previously, the WEE1 kinase had been demonstrated to be essential for delaying progression through the cell cycle in the presence of replication-inhibitory drugs, such as hydroxyurea. To understand the severe growth arrest of WEE1-deficient plants treated with hydroxyurea, a transcriptomics analysis was performed, indicating prolonged S-phase duration. A role for WEE1 during S phase was substantiated by its specific accumulation in replicating nuclei that suffered from DNA stress. Besides an extended replication phase, WEE1 knockout plants accumulated dead cells that were associated with premature vascular differentiation. Correspondingly, plants without functional WEE1 ectopically expressed the vascular differentiation marker VND7, and their vascular development was aberrant. We conclude that the growth arrest of WEE1-deficient plants is due to an extended cell cycle duration in combination with a premature onset of vascular cell differentiation. The latter implies that the plant WEE1 kinase acquired an indirect developmental function that is important for meristem maintenance upon replication stress

Multi-criteria assessment of integrating legumes into cropping systems across Europe

Integration of legumes into European agricultural systems would diversify the highly specialized cropping systems that are dominated by cereals and increase resource efficiency of agricultural systems. By providing high quality protein for food and feed as well as regulating and supporting services, legumes contribute essential ecosystem services. In order to assess the overall effects of legumes in agricultural systems, it is necessary to consider how legumes are integrated in cropping systems and evaluate the impacts of this integration. As legumes influence the production of other crops in the rotation and as the interaction of legumes are multiplex, an assessment of the cropping system that considers multiple criteria is required. The objective of this work was to assess the impacts of changes in crop rotations through the integration of legumes using cropping systems implemented in practice. We used a multi-actor approach to incorporate the knowledge of a range of legume experienced actors representing value chains with soybean, pea, faba bean, lupin and forages for food and feed and evaluate thereby the role of legumes in crop rotations of diverse systems from Ireland in the West to Ukraine in the East. Within the research process we firstly identified region-specific crop rotations with cultivation techniques based on expert opinion in the 17 different study areas. One rotation representing the current farming without legumes and at least one alternative legume-based crop rotation was specified per region. Secondly, a valid set of indicators was developed, including environmental, economic and agronomic indicators. The indicators were calculated for each cropping system at the rotational level, considering pre-crop effects i.e. adapted N fertilizer application rates and yields. Finally, the cropping system assessment compared current farming practices to legume-based alternatives. Trade-offs and synergies between different indicators e.g. gross margins and N fertilizer use were identified. On average, crop rotations with legumes reduced nitrous oxide emissions by 21% and 26% and N fertilizer use by 26% and 45% in arable and forage systems, respectively. While protein output was increased by 13% and 5%, energy output was reduced by 10% and 9% in arable and forage systems. Gross margin effects of introducing legumes were variable and site specific. Consideration of the full economic value of the crops as feed, subsidies for legumes, and the application of carbon taxes increased the relative performance of the legume-supported systems. The presented cropping system assessment within a multi-actor approach enables an exploration of the opportunities and challenges for integrating legumes in European crop rotations considering the views of local actors and can thereby provide multi-criteria guidance on the validation of potential alternative strategies.[https://pure.sruc.ac.uk/en/publications/multi-criteria-assessment-of-integrating-legumes-into-cropping-sy

Transition to legume‑supported farming in Europe through redesigning cropping systems

Legume-supported cropping systems afect environmental, production, and economic impacts. In Europe, legume production is still marginal with grain legumes covering less than 3% of arable land. A transition towards legume-supported systems could contribute to a higher level of protein self-sufciency and lower environmental impacts of agriculture. Suitable approaches for designing legume-supported cropping systems are required that go beyond the production of prescriptive solutions. We applied the DEED framework with scientists and advisors in 17 study areas in nine European countries, enabling us to describe, explain, explore, and redesign cropping systems. The results of 31 rotation comparisons showed that legume integration decreased N fertilizer use and nitrous oxide emissions (N2O) in more than 90% of the comparisons with reductions ranging from 6 to 142 kg N ha−1 and from 1 to 6 kg N2O ha−1, respectively. In over 75% of the 24 arable cropping system comparisons, rotations with legumes had lower nitrate leaching and higher protein yield per hectare. The assessment of above-ground biodiversity showed no considerable diference between crop rotations with and without legumes in most comparisons. Energy yields were lower in legume-supported systems in more than 90% of all comparisons. Feasibility and adaptation needs of legume systems were discussed in joint workshops and economic criteria were highlighted as particularly important, refecting fndings from the rotation comparisons in which 63% of the arable systems with legumes had lower standard gross margins. The DEED framework enabled us to keep close contact with the engaged research-farmer networks. Here, we demonstrate that redesigning legume-supported cropping systems through a process of close stakeholder interactions provides benefts compared to traditional methods and that a large-scale application in diverse study areas is feasible and needed to support the transition to legume-supported farming in Europe

Functional characterization of Medicago truncatula GRAS7, a member of the GRAS family transcription factors, in response to abiotic stress

AbstractTranscriptional factors play an essential role in the regulation of developmental processes in plants. GRAS family transcription factors are plant specific, and GRAS members possess multiple functions involved in plant growth and in response to abiotic and biotic stress. The members are divided into several subgroups. This study is focused on one particular member, MtGRAS7, which belongs to the PAT subgroup. Based on constructed stable transgenic plants with a gain and loss of function of MtGRAS7, the phenotype of transgenic plants was described compared to control wild-type Medicago trucatula. The involvement of the gene in the response to abiotic stress – drought (350 mmol/L mannitol), salinity (150 mmol/L NaCl) and cold (temperature of 4 °C), was analyzed and its transcript level was detected in leaves and nodules at different time points during the exposure to stress and after the stress. The overexpression of the gene benefits plant during the stress and later on in the recovery period