Alfalfa Genotypes Research Articles

Evaluation and selection of alfalfa genotypes for tolerance to aluminium toxic stress.

Alfalfa is one of the most important and the most cultivated crop due to its high nutritive quality and yield, but adaptation of alfalfa genotypes differ in terms of mobile aluminium stress in the soil. The aim of this study was to evaluate the tolerance to mobile Al concentrations in the laboratory and in the naturally acidic soil and select the promising genotypes based on agro-biological traits. In 2019, a laboratory experiment was conducted at the Institute of Agriculture of LAMMC. The experiment in the acidic soil with different mobile Al concentrations was conducted at the Vėžaičiai Branch of LAMMC. In 2020, the crops of alfalfa genotypes (11 cultivars and 3 populations) were established on Balthygleyic Dystric Retisol. The agro-biological traits were assessed during the 2021-2022 season. The tolerance index of hypocotyls and roots was evaluated using the filter-based screening method at different AlCl3 (0.0-64 mM) concentrations. The study results of the filter-based screening method showed that the genotype Žydrūnė, Malvina, Jõgeva 118, Skriveru, and 3130 were the most tolerant ones and the hypocotyl tolerance index of these genotypes was higher compared to medium tolerant genotypes Birutė, PGR12489, Europe and AJ2024 at 8, 16, 32 and 64 mM AlCl3 concentrations. The hypocotyl and root tolerance index of medium tolerant genotypes was higher compared to a sensitive genotype PGR10249 at 8 and 16 mM AlCl3. The study of cluster analysis with mobile Al 0.0-65.0 mg kg-1 showed that the genotypes Žydrūnė, Europe, AJ2024 and 3130 were the best in terms of wintering and spring regrowth, the cultivar Malvina had the best value of wintering, height before flowering and stem number, the cultivar Birutė had the best value of spring regrowth, height before flowering and seed yield, and the cultivar Skriveru had the best value of spring regrowth, height before flowering, stem number and seed yield.

Root-Zone Bacterial Diversity in Field-Grown Individual Plants from Alfalfa Lines with Wild Relatives in Their Genetic Backgrounds

Alfalfa (Medicago sativa L.) is a vitally important perennial fodder legume worldwide. Given their particular traits, alfalfa crop wild relatives (CWRs) could be used to develop cultivars that can tolerate extreme environmental and climatic conditions. Until now, researchers have overlooked the composition and structure of bacterial communities in the root zone of alfalfa and its relevant CWRs and their influence on forage performance under actual field conditions. In this study, high-throughput sequencing of 16S rRNA analysis was performed to investigate the diversity and assemblies of bacterial communities in the bulk soil and in the root zone of individual field-grown Medicago plants arranged in a honeycomb selection design. The plants used in this study were M. sativa × M. arborea hybrids (Genotypes 6 and 8), the closely-related M. sativa nothosubsp. varia (Martyn) Arcang. (Genotype 13), and M. sativa ssp. sativa (Genotype 20). The bacterial communities in the root-zone samples and the assemblies in the bulk soil differed significantly. Genotype 13 was found to have distinct bacterial assemblies from the other genotypes while exhibiting the lowest forage productivity. These findings suggest that plant productivity may influence the composition of bacterial communities in the root zone. Biomarker analysis conducted using linear discriminant analysis (LDA) revealed that only members of the Rhizobiales order were enriched in the M. sativa nothosubsp. varia root zone whereas taxa belonging to Sphingomonas and various Bacteriodota were enriched in the other genotypes. Of the shared taxa identified in the root zone of the Medicago lines, the abundance of specific taxa, namely, Flavisolibacter, Stenotrophomonas, and Sphingomonas, were positively associated with forage yield. This pioneering study, in which the root zones of individual Medicago plants under actual field conditions were examined, offers evidence of differences in the bacterial composition of alfalfa genotypes with varying genetic backgrounds. Its findings indicate that particular bacterial taxa may favorably influence plant performance. This study covered the first six months of crop establishment and paves the way for further investigations to advance understanding of how shifts in bacterial assemblies in alfalfa roots affect plant performance over time.

Comparative Phenotypic and Transcriptomic Analyses Provide Novel Insights into the Molecular Mechanism of Seed Germination in Response to Low Temperature Stress in Alfalfa.

Low temperature is the most common abiotic factor that usually occurs during the seed germination of alfalfa (Medicago sativa L.). However, the potential regulatory mechanisms involved in alfalfa seed germination under low temperature stress are still ambiguous. Therefore, to determine the relevant key genes and pathways, the phenotypic and transcriptomic analyses of low-temperature sensitive (Instict) and low-temperature tolerant (Sardi10) alfalfa were conducted at 6 and 15 h of seed germination under normal (20 °C) and low (10 °C) temperature conditions. Germination phenotypic results showed that Sardi10 had the strongest germination ability under low temperatures, which was manifested by the higher germination-related indicators. Further transcriptome analysis indicated that differentially expressed genes were mainly enriched in galactose metabolism and carbon metabolism pathways, which were the most commonly enriched in two alfalfa genotypes. Additionally, fatty acid metabolism and glutathione metabolism pathways were preferably enriched in Sardi10 alfalfa. The Weighted Gene Co-Expression Network Analysis (WGCNA) suggested that genes were closely related to galactose metabolism, fatty acid metabolism, and glutathione metabolism in Sardi10 alfalfa at the module with the highest correlation (6 h of germination under low temperature). Finally, qRT-PCR analysis further validated the related genes involved in the above pathways, which might play crucial roles in regulating seed germination of alfalfa under low temperature conditions. These findings provide new insights into the molecular mechanisms of seed germination underlying the low temperature stress in alfalfa.

Genetic diversity studies in local collections and advanced generations of lucerne (Medicago sativa L.) genotypes for fodder yield and yield-attributing traits

Precise information about genetic divergence is vital for a productive breeding program, as genetically diverse parents produce high heterotic effects, producing desirable segregants with higher yield levels. This study assessed seventy genotypes and four checks to estimate the extent of genetic diversity based on ten morphological traits attributed to yield. The genotypes showed significant differences for all the traits considered. Based on the Mahalanobis D2 statistics, the genotypes were grouped into ten clusters, with cluster I having the maximum number of genotypes, whereas cluster IX had a single genotype. The average inter-cluster distances revealed that the genotypes in clusters VI and VII were more diverse. In contrast, clusters I and III genotypes had the shortest inter-cluster distances, indicating genetic closeness. The study revealed a broad genotypic diversity within and between the alfalfa germplasm collections. The genotypes in clusters I, III, and V provide excellent genetic material for alfalfa yield improvement. They offer a possible way to exploit the existing variability to develop superior populations or composites

Discovering new genes for alfalfa (Medicago sativa) growth and biomass resilience in combined salinity and Phoma medicaginis infection through GWAS.

Salinity and Phoma medicaginis infection represent significant challenges for alfalfa cultivation in South Africa, Europe, Australia, and, particularly, Tunisia. These constraints have a severe impact on both yield and quality. The primary aim of this study was to establish the genetic basis of traits associated with biomass and growth of 129 Medicago sativa genotypes through genome-wide association studies (GWAS) under combined salt and P. medicaginis infection stresses. The results of the analysis of variance (ANOVA) indicated that the variation in these traits could be primarily attributed to genotype effects. Among the test genotypes, the length of the main stem, the number of ramifications, the number of chlorotic leaves, and the aerial fresh weight exhibited the most significant variation. The broad-sense heritability (H²) was relatively high for most of the assessed traits, primarily due to genetic factors. Cluster analysis, applied to morpho-physiological traits under the combined stresses, revealed three major groups of accessions. Subsequently, a GWAS analysis was conducted to validate significant associations between 54,866 SNP-filtered single-nucleotide polymorphisms (SNPs) and seven traits. The study identified 27 SNPs that were significantly associated with the following traits: number of healthy leaves (two SNPs), number of chlorotic leaves (five SNPs), number of infected necrotic leaves (three SNPs), aerial fresh weight (six SNPs), aerial dry weight (nine SNPs), number of ramifications (one SNP), and length of the main stem (one SNP). Some of these markers are related to the ionic transporters, cell membrane rigidity (related to salinity tolerance), and the NBS_LRR gene family (associated with disease resistance). These findings underscore the potential for selecting alfalfa genotypes with tolerance to the combined constraints of salinity and P. medicaginis infection.

Forage quality profiling of pre-selected alfalfa genotypes: towards genetic enhancement and adaptation for arid dryland farming

Forage quality profiling of pre-selected alfalfa genotypes: towards genetic enhancement and adaptation for arid dryland farming

Crops of alfalfa genotypes in the soil with very low and very toxic concentrations of mobile aluminium

Crops of alfalfa genotypes in the soil with very low and very toxic concentrations of mobile aluminium

Evaluation of New Alfalfa Genotypes for Forage, Quality and Seed Yield Potential under Different Field Trials

Evaluation of New Alfalfa Genotypes for Forage, Quality and Seed Yield Potential under Different Field Trials

THE PERFORMANS OF NEW ROMANIAN ALFALAFA (MEDICAGO SATIVA) GENOTYPES

Alfalfa (Medicago sativa), known as „Queen of the forages” is important for its biomass yield and it is the fourth most widely grown crop in the world behind corn, wheat and soybean. Therefore, alfalfa breeding targets forage yield and quality, as well as tolerance to biotic and abiotic stresses. The alfalfa genotypes have been tested in natural conditions to Agricultural and Research Station Caracal in 2020-2021 for assessing their yielding treats. Thus, the biomass yield ranged between 63,5 for F 2909-2 and 72,2 t/ha for F 2910, while dry matter emphasized significant values comparatively with the control (3-11%), only for the genotypes F2907, F2909-1, F2910. The genotypes Ileana and F2910 performed the best in all assessed traits and they are recommended for extended cropping system.

Association studies for yield and yield components in lucerne (Medicago sativa L.) genotypes.

An investigation was carried out to evaluate seventy lucerne ( L.) genotypes during 2020-Medicago sativarabi 21 at SRRS, IGFRI, Dharwad to determine the character association of ten morphological traits to improve the fodder yield. Analysis of variance revealed significant differences between the genotypes for all the traits studied. Correlation analysis revealed that dry fodder yield, plant height, number of branches per plant were significantly and positively associated at genotypic as well as phenotypic level with green fodder yield. Inter-correlation study revealed that a positive and significant association was found among plant height, number of branches per plant and dry fodder yield. The leaf to stem ratio, on the other hand, was negatively associated with green fodder yield. The results of path analysis revealed that dry fodder yield had the highest positive direct effect on green fodder yield, followed by plant height and number of branches per plant. While plant height and number of branches per plant contributed indirectly via dry fodder yield for green fodder yield.The study indicated that these characters would enhance the effectiveness of selection for higher fodder yield in lucerne

Exploring root system architecture and anatomical variability in alfalfa (Medicago sativa L.) seedlings

BackgroundThe growth of alfalfa (Medicago sativa L.) is significantly hampered by drought and nutrient deficiencies. The identification of root architectural and anatomical characteristics holds paramount importance for the development of alfalfa genotypes with enhanced adaptation to adverse environmental conditions. In this study, we employed a visual rhizobox system to investigate the variability in root system architecture (including root depth, root length, root tips number, etc.), anatomical features (such as cortical traits, total stele area, number and area of vessel, etc.), as well as nitrogen and phosphorus uptake across 53 alfalfa genotypes during the seedling stage.ResultsOut of the 42 traits measured, 21 root traits, along with nitrogen (N) and phosphorus (P) uptake, displayed higher coefficients of variation (CVs ≥ 0.25) among the tested genotypes. Local root morphological and anatomical traits exhibited more significant variation than global root traits. Twenty-three traits with CVs ≥ 0.25 constituted to six principal components (eigenvalues > 1), collectively accounting for 88.0% of the overall genotypic variation. Traits such as total root length, number of root tips, maximal root depth, and others exhibited positive correlations with shoot dry mass and root dry mass. Additionally, total stele area and xylem vessel area showed positive correlations with N and P uptake.ConclusionsThese root traits, which have demonstrated associations with biomass and nutrient uptake, may be considered for the breeding of alfalfa genotypes that possess efficient resource absorption and increased adaptability to abiotic stress, following validation during the entire growth period in the field.

Silicon supplementation and jasmonate activation synergistically increase phenolic defences against a legume herbivore

Abstract The accumulation of silicon (Si) is widely reported to have anti‐herbivore defensive properties in grasses. There is emerging, but fragmentary, evidence that Si could play a similar role in legumes. Here, we sought to understand the effects of Si supplementation on anti‐herbivore defensive properties in lucerne (Medicago sativa), especially in relation to other potential defences (i.e. phenolics) and the phytohormone that regulates anti‐herbivore defences, jasmonic acid or jasmonate (JA), which is also linked to Si accumulation. We determined how growth, root nodulation and chemistry (carbon, nitrogen and phenolic concentrations) of four genotypes of lucerne responded to Si supplementation, with and without the application of JA, and we used feeding assays to determine the subsequent effects on the feeding success of adult Sitona discoideus weevils. Si supplementation increased plant mass and root nodulation of M. sativa by 61% and 227%, respectively, and reduced relative consumption (RC) and frass production by S. discoideus by 38% and 30% respectively. Si supplementation had no effect on foliar nitrogen concentrations, most likely due to the dilution effects of increased plant growth and foliar carbon. Phenolic concentrations were negatively correlated with leaf RC; RC also decreased by 34% when JA was applied to plants. When Si was combined with JA application, phenolics were significantly enhanced, demonstrating the potential to stimulate multiple anti‐herbivore properties in M. sativa. Overall, the Si‐ and JA‐induced phytochemical and herbivore feeding responses were consistent between the four lucerne genotypes tested. Synthesis. The novel findings suggest that Si accumulation may play a more important role in legume resistance to herbivorous animals than previously thought. The ubiquity of soil Si and its emerging functional role in plant biology, including plant–animal interactions, suggest that these patterns could be common among legumes.

Defoliation management affects performance of alfalfa–bermudagrass mixtures in the southeastern United States

AbstractOverseeding alfalfa (Medicago sativa L.) into grass swards increases forage nutritive value and reduces N fertilizer requirement. In warm climates, establishing and maintaining alfalfa in mixtures with vigorous C4 grasses is challenging, which makes adjustment of defoliation management critical. The objective of this 2‐year study was to determine optimal harvest stubble height (SH; 5, 10, and 15 cm) and cutting interval (CI; 2, 4, and 6 weeks) for two alfalfa genotypes (“Bulldog 805,” and breeding line UF Alf Pers 2015 [UF 2015‐AP]) in mixture with “Tifton 85” bermudagrass (Cynodon spp.). When statistical differences occurred, shorter SH resulted in greater mixture forage accumulation (FA), with this effect generally more pronounced for UF 2015‐AP than Bulldog 805, and for CI of 6 weeks than 2 or 4 weeks. Genotype did not affect alfalfa FA, but alfalfa FA was least for the 2‐week CI for all SH levels, and greatest for the 5‐cm SH when CI was 4 weeks, and for the 5‐ and 10‐cm SH when CI was 6 weeks. Alfalfa percent cover was generally greater for longer CI, regardless of SH. Mixture crude protein and digestibility were minimally affected by treatments because the expected negative effects of long CI on nutritive value were offset by greater alfalfa proportion in the mixture for these treatments. In this environment, CI was generally the most important factor affecting alfalfa persistence in alfalfa–bermudagrass mixtures. A short SH in combination with longer CI (4–6 weeks) resulted in the greatest mixture and alfalfa FA.

Selection of alfalfa genotypes for dry matter yield and persistence with repeated measures

The biggest challenge in the alfalfa breeding program is to obtain cultivars with high persistence, high productivity, and adaptability. Therefore, studies about selection methods are necessary for the success of alfalfa breeding programs. This study aimed to evaluate dry matter yield and persistence in alfalfa for selecting genotypes, using appropriate statistical models for experiments with repeated measures. The experiment was conducted at Embrapa Southeast Livestock, in São Carlos, state of São Paulo, Brazil in a randomized blocks design, in plots subdivided in time, with three replicates. Eight genotypes were evaluated, and the agronomic trait evaluated was dry matter yield. The experiments in split-plots were used with two and three errors and generalized linear models with the following correlation structures: composite symmetry (CS), heterogeneous composite symmetry (HCS), auto regressive (AR), heterogeneous auto regressive (HAR), and variance components (VC). The best model was selected according to the lowest value of the Akaike Information Criterion (AIC), and three methodologies were used to identify the genotype with greater productivity and persistence: Average test for multiple comparisons, adaptability, and stability by multi-information, and similarity between genotype and ideotype. The interaction between genotypes and cuts was significant, demonstrating the existence of the different behavior of the alfalfa genotypes over the cuts. Different methodologies allowed to measure the average yield of the alfalfa genotype and the persistence over the cuts. PSB 4 genotype demonstrated promissory behavior in terms of productivity and persistence throughout the production cycle of alfalfa.

Визначення посухостійкості популяцій люцерни насіннєвого використання за математичними індексами

The purpose of research. To evaluate the response of varieties and populations of seed alfalfa under different environments and to determine the best not only in terms of drought resistance, but also in terms of productivity under stress conditions with their further use in the breeding process. Methods. Research was conducted at the Institute of Irrigated Agriculture of the NAAS (now the Institute of climate smart agriculture of the NAAS) during 2017–2020. The object of study was 24 alfalfa populations for seed use. Resistance of alfalfa genotypes to stress was carried out using various mathematical indices and biplot analysis. Results. The hydrothermal coefficient (HTC) in 2017, 2018 and 2020 varied between 0.51 and 0.55, indicating very dry climatic conditions, while in 2019 it was 0.88, corresponding to dry conditions. 11 populations were characterized by high yield (>400 kg/ha) under stressful conditions. However, the best of these populations, which formed the highest seed productivity in the range of 445.5–472.1 kg/ha, A.–N. d. No. 15, Sin(c). / Prymorka and M.g. / CPU–11. According to the largest number of indices (9), the populations of A.–N. d. No. 15 and Sin(s). / Prymorka. Populations of M.g. / CP–11, which was characterized by the highest yield under stress, stood out according to four indices. The population T. / Emeraude population, which was characterized by one of the smallest reductions in yield and high yield under worse conditions, was distinguished by seven indices. Correlations between seed yield under different growing conditions and drought resistance indices were also analyzed. According to the results of GGE biplot analysis, the most drought–resistant population of M.g. / CP–11, Sin(s) population. / Prymorka and A.–N.d. No. 15 form a high yield of seeds under both conditions, and the selection according to k.s. has low productivity under worse conditions, but dramatically improves it when growing conditions are improved. Conclusions. The most promising alfalfa populations are identified and divided into groups by seed productivity.

Comparison of Some Alfalfa (Medicago sativa L.) Genotypes in terms of Herbage Quality Characters

Comparison of Some Alfalfa (Medicago sativa L.) Genotypes in terms of Herbage Quality Characters

Comparative time-course transcriptome analysis of two contrasting alfalfa (Medicago sativa L.) genotypes reveals tolerance mechanisms to salt stress.

Salt stress is a major abiotic stress affecting plant growth and crop yield. For the successful cultivation of alfalfa (Medicago sativa L.), a key legume forage, in saline-affected areas, it's essential to explore genetic modifications to improve salt-tolerance.Transcriptome assay of two comparative alfalfa genotypes, Adina and Zhaodong, following a 4 h and 8 h's 300 mM NaCl treatment was conducted in this study in order to investigate the molecular mechanism in alfalfa under salt stress conditions. Results showed that we obtained 875,023,571 transcripts and 662,765,594 unigenes were abtained from the sequenced libraries, and 520,091 assembled unigenes were annotated in at least one database. Among them, we identified 1,636 differentially expression genes (DEGs) in Adina, of which 1,426 were up-regulated and 210 down-regulated, and 1,295 DEGs in Zhaodong, of which 565 were up-regulated and 730 down-regulated. GO annotations and KEGG pathway enrichments of the DEGs based on RNA-seq data indicated that DEGs were involved in (1) ion and membrane homeostasis, including ABC transporter, CLC, NCX, and NHX; (2) Ca2+ sensing and transduction, including BK channel, EF-hand domain, and calmodulin binding protein; (3) phytohormone signaling and regulation, including TPR, FBP, LRR, and PP2C; (4) transcription factors, including zinc finger proteins, YABBY, and SBP-box; (5) antioxidation process, including GST, PYROX, and ALDH; (6) post-translational modification, including UCH, ubiquitin family, GT, MT and SOT. The functional roles of DEGs could explain the variations in salt tolerance performance observed between the two alfalfa genotypes Adina and Zhaodong. Our study widens the understanding of the sophisticated molecular response and tolerance mechanism to salt stress, providing novel insights on candidate genes and pathways for genetic modification involved in salt stress adaptation in alfalfa.

Симбиотическая эффективность биотипов люцерны изменчивой сорта Таисия

The variety of alfalfa Taisiya was created using the methods of conjugate symbiotic breeding. Two genotypes of alfalfa with high adaptive capacity were selected on a special selective background. One plant had lilac flowers, the other yellow. A plant with yellow flowers was used as a mother form, with lilac — father's. The color of the flowers of hybrid plants varies from light cream to dark purple. Basically, the population is represented by plants with variegated flowers. It has been established that variegated biotypes are the most stable in the population of variable alfalfa of the Taisiya variety. In the third year of use in the variant without inoculation on medium-cultivated soil, their productivity was 6.3 g/row of dry matter, 4.9 blue-flowered, 5.2 g/row yellow-flowered. On cultivated soil — 4.6 g/row, the rest — 3.3 and 2.7 g/row of dry matter. In medium-cultivated soil, pre-sowing inoculation of variegated biotypes with strain 404b increased productivity in the first and third years of use by 33–35%, in poorly cultivated soil — by 31–93%, and inoculation with strain 415b — by 35–52%. On poorly cultivated soil, the highest productivity gains (48–130%) were obtained by inoculation of yellow-flowered biotypes with strain 404b.

Comparative Transcriptome and Anatomic Characteristics of Stems in Two Alfalfa Genotypes.

Stems are more important to forage quality than leaves in alfalfa. To understand lignin formation at different stages in alfalfa, lignin distribution, anatomical characteristics and transcriptome profile were employed using two alfalfa cultivars. The results showed that the in vitro true digestibility (IVTD) of stems in WL168 was significantly higher than that of Zhungeer, along with the significantly lower neutral detergent fiber (NDF), acid detergent fiber (ADF) and lignin contents. In addition, Zhungeer exhibited increased staining of the xylem areas in the stems of different developmental stages compared to WL168. Interestingly, the stems of WL168 appeared intracellular space from the stage 3, while Zhungeer did not. The comparative transcriptome analysis showed that a total of 1993 genes were differentially expressed in the stem between the cultivars, with a higher number of expressed genes in the stage 4. Of the differentially expressed genes, starch and sucrose metabolism as well as phenylpropanoid biosynthesis pathways were the most significantly enriched pathways. Furthermore, expression of genes involved in lignin biosynthesis such as PAL, 4CL, HCT, CAD, COMT and POD coincides with the anatomic characteristics and lignin accumulation. These results may help elucidate the regulatory mechanisms of lignin biosynthesis and improve forage quality in alfalfa.

Adaptation des génotypes de luzerne pérenne à l’environnement hors oasien en vue d’améliorer les performances de l’agro-système du sud Tunisien

La sélection de la luzerne dans des zones à fortes contraintes abiotiques a peu progressé dans l’amélioration de la productivité et de la tolérance. La difficulté réside dans l’identification et la caractérisation des paramètres liés à la résistance aux différentes pressions climatiques. Divers processus phénologiques, morphologiques, physiologiques et chimiques sont à l’origine des stratégies d’évitement et de tolérance. Le but de ce travail était d’étudier les divergences morpho-physiologiques et chimiques entre huit génotypes de luzerne pérenne d’origines différentes : 3 génotypes locaux (IRA, Gabès, Chenini) et cinq exotiques (Ameristand, Bami, Prosementi, Tamentit et Tata) ayant montré une grande tolérance au bioclimat aride en dehors de l’oasis. Les résultats obtenus ont permis d’identifier deux groupes de génotypes suffisamment homogènes qui pourraient être considérés comme un patrimoine génétique intéressant pour les critères de sélection choisis. Ce pool pourra être le matériel génétique de départ pour la création de variétés synthétiques adaptées aux conditions arides en dehors des oasis caractérisées par des rendements frais et secs plus élevés (Ameristand, Bami, et Tamentit), avec une excellente tolérance à la salinité (Gabès et IRA).