PIRMO KURSO STUDENTŲ GEOGRAFIJOS STUDIJŲ PROGRAMŲ PASIRINKIMO MOTYVAI

This article analyzes the reasons of choosing geography study research conducted at three universities in Lithuania – Lithuanian Education University (LEU), Vilnius (the VU) and Klaipeda (hereafter KU), and spanning 2009–2013 school year. The overall objective of the study – to find out the reasons for undergraduate students (first-year graduates) who has chosen to study geography and to reveal the changes in the completion of training. This article deals only with the first-year student survey results. This article presents the social-demographic characteristics of students, universities and courses of choice motives and conclusions are formulated, including the first-year university geography student survey results. Usefulness of the results is based on the curriculum development and renewal of the use, in order to attract a larger number of students who choose geographer specialty. Increasing mobility within the European Union, changing education funding policies and priorities determined by the academic challenges of the new country life and choice of study. Study selection considerations are becoming increasingly complex and serious.KEY WORDS: geography studies, study selection, motivation, geography

GEOGRAFIJOS STUDIJŲ PROGRAMŲ PASIRINKIMO MOTYVACIJA

2009–2012 school year, Education University of Lithuania (hereinafter referred to LEU) Social Geography and Tourism Department has initiated the study of geography and the reasons for the choice of study LEU, Vilnius (hereinafter referred to VU) and Klaipeda (hereinafter referred to KU) University. It is quite extensive, ongoing study to determine the reasons for undergraduate students (first-year students and graduates) who have chosen to study geography and to reveal the changes in the end of their studies, carried out a detailed analysis of the results. These results are necessary and useful for improving geography education programs in order to justify the expectations of learners, to attract a greater number of students who want to choose a specialty geographer. Widening the European Union in space, changes in scientific principles and priorities for funding leads to new challenges in the academic life of the country, increased mobility. Prospective students from Lithuania, including geography, becomes better and awareness of opportunities for similar studies at both national and foreign institutions of higher education. This article discusses and analyzes the results of the survey of geography graduates identified their degree program selection and evaluation of motives. KEY WORDS: Geography studies, study selection, motivation, graduate, geography

Association analysis of five candidate genes with plant height and dry matter yield in perennial ryegrass

Five candidate genes LpIAA1, LpRUB1, LpBRI1, LpSHOOT1 and LpTB1 with putative function in plant architecture were allele sequenced in a panel of 96 diploid perennial ryegrass genotypes of diverse origin. The total length of the non-redundant genomic DNA alignment was 5425 bp and revealed 270 polymorphic sites in total. A negative significant Tajima’s D value was detected in LpTB1 gene, suggesting selection pressure for low frequency alleles in this gene. All 96 genotypes were evaluated for plant height and dry matter yield over two years. Marker – trait associations were calculated between polymorphic sites and both phenotypic traits. Three indels and three single nucleotide substitutions in LpTB1 gene were significantly (p \u3c 0.05, q \u3c 0.05) associated with plant height, while one indel was associated with dry matter yield. The results suggest putative role of LpTB1 gene in plant height determination in perennial ryegrass and provide means for target allele selection

Inter-simple sequence repeat (ISSR) loci mapping in the genome of perennial ryegrass

The aim of this study was to identify and characterize new ISSR markers and their loci in the genome of perennial ryegrass. A subsample of the VrnA F2 mapping family of perennial ryegrass comprising 92 individuals was used to develop a linkage map including inter-simple sequence repeat markers (ISSR). Twelve ISSR fragments out of 29 were mapped to the linkage groups (LG) LG1, LG2, LG4, LG6 and LG7. The total map length was 250.7 cM. Selected ISSR fragments were cloned by transformation into plasmid pTZ57R and sequenced. For four ISSRs, BLAST search revealed a significant similarity to coding regions of known sequences within the current DNA databases. An ISSR fragment of 580 bp, produced by the (GACA) 4 TC primer present on LG6, showed a 95% identity to the Avena sativa L. transposon and repetitive DNA linked to the receptor kinase gene. A 780 bp fragment generated by (TG) 8 RT primer demonstrated a 70% similarity to the Hordeum vulgare germin gene GerA. Inter-SSR mapping will provide useful information for gene targeting, quantitative trait loci mapping and marker-assisted selection in perennial ryegrass. Inter-simple sequence repeat (ISSR) loci mapping in the genome of perennial ryegrass

Impact of Combined Drought and Heat Stress and Nitrogen on Winter Wheat Productivity and End-Use Quality

Water deficit and heat stress are the main abiotic stresses affecting the yield and quality of winter wheat. The increasing frequency of the simultaneous occurrence of these two stresses might threaten global food security and drives the need to breed resilient high-quality cultivars. The aim of this study was to evaluate the grain yield, quality and gluten protein characteristics in 50 winter wheat cultivars and breeding lines during the harvest years of 2018 and 2019. The yield and grain quality components were affected more severely by the combined heat and drought in 2019 than the drought in 2018. Two nitrogen (N) fertilization regimes were studied, sustainable (S, 15/100/30 kg N ha(-1)) and high-input (HI, 15/100/100 kg N ha(-1)). The yield was higher in HI trials compared to S trials by 2.2 t ha(-1) in 2018 and by 2.4 t ha(-1) in 2019. Higher protein content and sedimentation volume and lower yield, test weight and starch content were observed under combined heat and drought stress in 2019 compared to 2018. Genotypes containing the Glu-D1 x5-y10 allele exhibited the higher amounts of unextractable polymeric proteins (%UPP = 58.5%) in gluten studied by size exclusion liquid chromatography (SE-HPLC) as compared to Glu-D1 x2-y12 allele (%UPP = 54.3%). Genotype was the main determinant of gluten protein characteristics regardless of the nitrogen application and the abiotic stress conditions. The results suggest that the relatively mild drought and heat events in Lithuania might not threaten gluten quality in the future; however, breeding efforts should be directed towards improved drought and heat stress resistance to ensure stable wheat productivity in the region

Identification of genomic loci associated with crown rust resistance in perennial ryegrass (Lolium perenne L.) divergently selected populations

The inheritance of crown rust resistance in perennial ryegrass is complex with both major and minor quantitative trait loci (QTL) being detected on all seven linkage groups. However, QTL mapping populations have only few segregating alleles, limiting the transferability of results to other materials. In this study, a synthetic population was developed from four crown rust resistant and susceptible parents as starting material for a divergent selection experiment of crown rust resistance to be closer to practice in plant breeding programs, and to identify genome regions relevant across a broader range of genotypes. Following three cycles of directional selection, perennial ryegrass populations were produced with a two-fold difference in average rust resistance. Divergently selected populations were genotyped at 7 resistance gene analog-derived expressed sequence tag (RGA-derived EST) as well as 15 simple sequence repeat (SSR) loci. A test for selective neutrality (Waples test), which tests the hypothesis of genetic drift versus selection, identified significant differences in allele frequencies for 7 loci (32%). The selection effect was bidirectional with the same loci showing significant response in both positively and negatively selected populations. A region under selection represented by markers LpSSR006 and EST13 on linkage group (LG) 4 was further confirmed by colocation with two separate QTL for crown rust resistance in a VrnA, a two-way pseudo-testcross mapping population. This suggests suitability of alleles identified for introgression into perennial ryegrass germplasm, where quantitative resistance to crown rust is desired

Affordable phenotyping of winter wheat under field and controlled conditions for drought tolerance

Drought stress is one of the key plant stresses reducing grain yield in cereal crops worldwide. Although it is not a breeding target in Northern Europe, the changing climate and the drought of 2018 have increased its significance in the region. A key challenge, therefore, is to identify novel germplasm with higher drought tolerance, a task that will require continuous characterization of a large number of genotypes. The aim of this work was to assess if phenotyping systems with low-cost consumer-grade digital cameras can be used to characterize germplasm for drought tolerance. To achieve this goal, we built a proximal phenotyping cart mounted with digital cameras and evaluated it by characterizing 142 winter wheat genotypes for drought tolerance under field conditions. The same genotypes were additionally characterized for seedling stage traits by imaging under controlled growth conditions. The analysis revealed that under field conditions, plant biomass, relative growth rates, and Normalized Difference Vegetation Index (NDVI) from different growth stages estimated by imaging were significantly correlated to drought tolerance. Under controlled growth conditions, root count at the seedling stage evaluated by imaging was significantly correlated to adult plant drought tolerance observed in the field. Random forest models were trained by integrating measurements from field and controlled conditions and revealed that plant biomass and relative growth rates at key plant growth stages are important predictors of drought tolerance. Thus, based on the results, it can be concluded that the consumer-grade cameras can be key components of affordable automated phenotyping systems to accelerate pre-breeding for drought tolerance

Genome-Wide Association Analysis and Genomic Prediction for Adult-Plant Resistance to Septoria Tritici Blotch and Powdery Mildew in Winter Wheat

Septoria tritici blotch (STB) caused by the fungal pathogen Zymoseptoria tritici and powdery mildew (PM) caused by Blumeria graminis f.sp tritici (Bgt) are among the forefront foliar diseases of wheat that lead to a significant loss of grain yield and quality. Resistance breeding aimed at developing varieties with inherent resistance to STB and PM diseases has been the most sustainable and environment-friendly approach. In this study, 175 winter wheat landraces and historical cultivars originated from the Nordic region were evaluated for adult-plant resistance (APR) to STB and PM in Denmark, Estonia, Lithuania, and Sweden. Genome-wide association study (GWAS) and genomic prediction (GP) were performed based on the adult-plant response to STB and PM in field conditions using 7,401 single-nucleotide polymorphism (SNP) markers generated by 20K SNP chip. Genotype-by-environment interaction was significant for both disease scores. GWAS detected stable and environment-specific quantitative trait locis (QTLs) on chromosomes 1A, 1B, 1D, 2B, 3B, 4A, 5A, 6A, and 6B for STB and 2A, 2D, 3A, 4B, 5A, 6B, 7A, and 7B for PM adult-plant disease resistance. GP accuracy was improved when assisted with QTL from GWAS as a fixed effect. The GWAS-assisted GP accuracy ranged within 0.53-0.75 and 0.36-0.83 for STB and PM, respectively, across the tested environments. This study highlights that landraces and historical cultivars are a valuable source of APR to STB and PM. Such germplasm could be used to identify and introgress novel resistance genes to modern breeding lines

Phenotyping a Dynamic Trait: Leaf Growth of Perennial Ryegrass Under Water Limiting Conditions

Water limitation is one of the major factors reducing crop productivity worldwide. In order to develop efficient breeding strategies to improve drought tolerance, accurate methods to identify when a plant reduces growth as a consequence of water deficit have yet to be established. In perennial ryegrass (Lolium perenne L.), an important forage grass of the Poaceae family, leaf elongation is a key factor determining plant growth and hence forage yield. Although leaf elongation has been shown to be temperature-dependent under non-stress conditions, the impact of water limitation on leaf elongation in perennial ryegrass is poorly understood. We describe a method for quantifying tolerance to water deficit based on leaf elongation in relation to temperature and soil moisture in perennial ryegrass. With decreasing soil moisture, three growth response phases were identified: first, a “normal” phase where growth is mainly determined by temperature, second a “slow” phase where leaf elongation decreases proportionally to soil water potential and third an “arrest” phase where leaf growth terminates. A custom R function was able to quantify the points which demarcate these phases and can be used to describe the response of plants to water deficit. Applied to different perennial ryegrass genotypes, this function revealed significant genotypic variation in the response of leaf growth to temperature and soil moisture. Dynamic phenotyping of leaf elongation can be used as a tool to accurately quantify tolerance to water deficit in perennial ryegrass and to improve this trait by breeding. Moreover, the tools presented here are applicable to study the plant response to other stresses in species with linear, graminoid leaf morphology

A transnational and holistic breeding approach is needed for sustainable wheat production in the Baltic Sea region

The Baltic Sea is one of the largest brackish water bodies in the world. Eutrophication is a major concern in the Baltic Sea due to the leakage of nutrients to the sea with agriculture being the primary source. Wheat (Triticum aestivum L.) is the most widely grown crop in the countries surrounding the Baltic Sea and thus promoting sustainable agriculture practices for wheat cultivation will have a major impact on reducing pollution in the Baltic Sea. This approach requires identifying and addressing key challenges for sustainable wheat production in the region. Implementing new technologies for climate-friendly breeding and digital farming across all surrounding countries should promote sustainable intensification of agriculture in the region. In this review, we highlight major challenges for wheat cultivation in the Baltic Sea region and discuss various solutions integrating transnational collaboration for pre-breeding and technology sharing to accelerate development of low input wheat cultivars with improved host plant resistance to pathogen and enhanced adaptability to the changing climate.Peer reviewe