Alfalfa Populations Research Articles

Coumestrol content in alfalfabreeding populations

Aim. Alfalfa is a rich source of phytoestrogens, among them coumestrol which shows strong estrogenic activity that can adversely affect the health of domestic animals. The aim of the study was to determine the variation in coumestrol content in leaves of alfalfa breeding populations, present in the breeding program of Agricultural Institute Osijek in Croatia. Method. Twelve alfalfa populations were selected based on their high forage yield and good persistence. Coumestrol was extracted using acidifi ed methanol as an organic solvent from lyophilized and ground alfalfa leaves, while for detection and quantifi cation was used. Results. Signifi cant differences were observed between the studied populations with average coumestrol content of 435.67 mg/kg of dry matter (DM). The highest content of coumestrol was determined in breeding population Rs-21 (619.53 mg/kg of DM). Conclusions. Populations Rs-33 and Rs-20 had the lowest coumestrol content (82.18 and 86.58 mg/kg, respectively) and present a potential breeding source for creat- ing new contemporary cultivars with decreased coumestrol content

Physiological and Biochemical Responses to Salt Stress of Alfalfa Populations Selected for Salinity Tolerance and Grown in Symbiosis with Salt-Tolerant Rhizobium

Alfalfa and its rhizobial symbiont are sensitive to salinity. We compared the physiological responses of alfalfa populations inoculated with a salt-tolerant rhizobium strain, exposed to five NaCl concentrations (0, 20, 40, 80, or 160 mM NaCl). Two initial cultivars, Halo (H-TS0) and Bridgeview (B-TS0), and two populations obtained after three cycles of recurrent selection for salt tolerance (H-TS3 and B-TS3) were compared. Biomass, relative water content, carbohydrates, and amino acids concentrations in leaves and nodules were measured. The higher yield of TS3-populations than initial cultivars under salt stress showed the effectiveness of our selection method to improve salinity tolerance. Higher relative root water content in TS3 populations suggests that root osmotic adjustment is one of the mechanisms of salt tolerance. Higher concentrations of sucrose, pinitol, and amino acid in leaves and nodules under salt stress contributed to the osmotic adjustment in alfalfa. Cultivars differed in their response to recurrent selection: under a 160 mM NaCl-stress, aromatic amino acids and branched-chain amino acids (BCAAs) increased in nodules of B-ST3 as compared with B-TS0, while these accumulations were not observed in H-TS3. BCAAs are known to control bacteroid development and their accumulation under severe stress could have contributed to the high nodulation of B-TS3.

Exploring the diversity of alfalfa within Brazil for tropical production

Alfalfa (Medicago sativa L.) is a forage legume of great interest because of its role in milk production schemes. Although it has the potential to be cultivated in different edaphoclimatic regions, the fodder production in tropical regions is limited. The objectives of this study were to perform phenotypic and molecular characterization of alfalfa germplasm, to examine the relationship between dissimilarity based on phenotypic and molecular information and to identify the germplasm with potential to generate base populations adapted to tropical conditions. The genetic values of nine traits from seventy-seven alfalfa accessions of a genetic background amenable to a temperate climate were obtained to characterize phenotypic diversity, and microsatellite markers were used to assess molecular diversity. Phenotypic information based on joint deviance analysis revealed the presence of genetic diversity. The correlation between the dissimilarity matrices of genetic values and molecular data was low. Based on phenotypic and molecular data, a great base population would be composed of Pro INTA Patricia, Pro INTA Super Monarca, Mecha, Magna 601, WL 525, ACA 900, Bacana, CUF 101, Crioula, and Ruano. These populations have at least 50 distinct parents, presented high dry matter yield, besides favorable alleles for regrowth ability, biomass yield, and persistence. The genetic variability observed for most traits indicates a high potential for the development of alfalfa base populations adapted to the tropical condition. Once adapted synthetic alfalfa populations are selected, they may be integrated into breeding programs in other tropical regions of the world.

Competition Indicator in Alfalfa Populations Following Recurrent Selection to Glyphosate Tolerance

The bad cide in adopting cide-tolerant alfalfa cultivar is the shift in weed communities with rise proportion of tolerant species. The main objective of the recent study was to trace competition indicator of alfalfa populations as affected by recurrent selection to glyphosate tolerance. Two cycles of recurrent selection for Glyphosate tolerance were imposed on each base population. Competition indicators following selection included plant characters and weed bioassay. In most studied populations, plant height decreased with the first cycle of selection to glyphosate tolerance by -8.991, -3.225, -1.240 and -0.426% in Siwa, Hasawi, C.U.F101 and Baladi1 populations, respectively. Except for, Sirivar population an increase by +6.740 % was accompanied with selection to glyphosate tolerance. On the other hand, by cycle two of selection, populations had different response relative to C1, where Baladi1, C.U.F101 and Sirivar populations had a decrease in plant height with values reached -1.761, -0.720 and 0.617 cm, respectively. While, Hasawi and Siwa populations showed an increased plant height by +3.816 and +3.197cm, respectively. Glyphosate treated plots (+ and -) were evaluated by weed bioassay in terms of green and dry weight during a course of three successive cuttings. Exposed genetic materials to glyphosate treatments were selection cycles (C0, C1 and C2) of the five studied populations.The first cycle of selection to glyphosate tolerance expressed a significant increase of 9.59 and 10.93% relative to the base population as green and dry weed weights, when evaluated under glyphosate treating condition. The second cycle of selection was associated with a reduction of 29.63 and 28.88% in green and dry weight of weed. This might indicate a proliferation of alfalfa plants that were selected for glyphosate tolerance, the matter that reduced the mass of weeds, whether, as green or dry weight.

Food value of some populations of Algerian annual alfalfa

Fodder grown in Algeria occupies 20% of the total UAA (agricultural area use) of the country. They are dominated by so-called "dry" fodder. The conversion of northern fallow land and steppe to self-regenerating legumes in an annual Cereal / Medicago rotation system may increase it. At the early flowering stage, the results indicate that the mineral content of the annual alfalfa is consistent; it varies from 9 to 14% of the DM (Dry matter). The species M. truncatula (Tr238) has the highest value (18%), which decreases the organic matter content. The nitrogen content is high with a maximum of 29% M ciliaris(S5) and a minimum of 20% M. intertexta (I107): the M. ciliaris species is the best provided in MAT (total nitrogenous matter) with an average of 27% against M. intertexta: 23 %. The highest NDF (neutral detergent fibre) content, 46% of the MS (dry matter) is recruited among M. intertexta (I253) quite logically, ADF (acid detergent fibre) and ADL (lignin) follow with 21 and 9% as respective maximas for all populations. However, on average, the ADL content is only 5% with a minimum of 2.6% for C2 M. ciliaris. It is interesting to note, the positive sign of the correlation between factors N. of Rods / m² and ADF: the amount of DM (thus indirectly lignin) increases in parallel with the age of the plant, as NDF and ADF. Considered first by test, the recorded digestibility values are equal to or greater than 70%: 75; 73; 74; 79 (respectively for tests 1 to 4) and on average, 75%. The average digestibility per species is 77; 73 and 75% for M ciliaris, M truncatula and M intertexta. Variations between populations and species are low: 3.4 and 3.1% respectively. The 20 or so populations of local annual alfalfa studied showed a great genetic variability of the studied parameters, which constitutes an important genetic capital in which the breeder could draw at leisure. Abbreviations: MAT, total nitrogenous matter ;ADF, acid detergent fibre; DM, dry matter; UAA, agricultural area use,; NDF, neutral detergent fibre ; N. of Rods / m² ,Number of Rods / m².

Competition Indicator in Alfalfa Populations Following Recurrent Selection to Glyphosate Tolerance

Competition Indicator in Alfalfa Populations Following Recurrent Selection to Glyphosate Tolerance

Identification of transcripts associated with the acquisition of superior freezing tolerance in recurrently-selected populations of alfalfa

The identification of transcripts that vary during the acquisition of superior tolerance to environmental stress contribute to the understanding of the molecular bases of adaptation to adverse growth conditions. SRAP-cDNA was used to identify genes that were differentially expressed between plants of alfalfa (Medicago sativa L.) that were non-acclimated (NA) or hardened to a non-lethal freezing temperature (HF). Search of polymorphism was performed within the cultivar Apica (ATF0) and population ATF5 obtained after five cycles of recurrent selection for superior tolerance to freezing (TF) within ATF0. Analysis of bulked cDNA from 50 non-acclimated and 50 cold-acclimated plants in each population identified transcripts that vary in abundance in response to acclimation to sub-zero temperature and recurrent selection. Sequencing of purified fragments revealed significant homologies with genes with key physiological functions that are distributed across the Medicago truncatula genome. Regulatory genes including receptor-like kinases, a phytochrome-interacting factor and a phosphoinositide phosphatase are among potential candidates involved in the improvement of freezing tolerance by RS. RT-qPCR analysis of samples from populations recurrently selected within the cultivars Apica and Evolution confirmed the common cold-induced responses in unrelated genetic backgrounds. Our results show that random amplification of cDNA in combination with bulk segregant analysis of pooled samples from recurrently selected populations is an effective strategy to identify functional sequences putatively associated with superior acclimation to environmental stress in open-pollinated species.

Variation of Phytoestrogen Content and Major Agronomic Traits in Alfalfa (Medicago sativa L.) Populations

Alfalfa is the main perennial legume and a rich source of phytoestrogens. Variation of phytoestrogen content and agronomic traits was evaluated in twenty alfalfa populations over two consecutive years. The most dominant phytoestrogen in alfalfa populations was genistein, while slightly lower levels were found for kaempferol and coumestrol. Several populations (Af 1, 12, 18, 19, 20) showed superior agronomic performance, especially high forage yield (up to 71.93 t ha−1). These populations were also characterized by a lower (Af 1, 12, 18, 20) or high (Af 1, 19) content of total and individual phytoestrogens, including Af 8 population with the highest total content (2637.10 μg g-1 of DM) and content of most of the individual phytoestrogens and favorable agronomic properties. Ward hierarchical clustering method grouped the twenty evaluated populations into four distinct clusters. Identified materials provide a valuable source of germplasm for further breeding programs in order to develop new high-yielding cultivars with either low (for forage use) or high (for possible pharmaceuticals/nutraceuticals industries) phytoestrogen content.

Influence of different strains of Sinorhizobium meliloti on the level of symbiosis in alfalfa populations

Influence of different strains of Sinorhizobium meliloti on the level of symbiosis in alfalfa populations

Determining the performance of alfalfa population collected from a narrow agroeceological zone of Turkey

ABSTRACT: This study was carried out to determine the yield and quality characteristics of some alfalfa village populations cultivated by producers in Bingol province of Turkey. Alfalfa seeds were obtained from 23 different locations in 2015. A three replicated, randomised complete block designed field trial was established in 2016 including these genotypes and four registered varieties. As a result of three year trials, it was determined that the populations obtained from the villages of Servi, Mutluca, Garip, Sarıçiçek-1 and Bagliisa produced highest green herbage and hay yields. When we compare the quality results, Kumgecit, Küçüktekören and Şenköy-1 populations stands out in terms of crude protein ratio. Highest crude protein yield was obtained from Servi population. In terms of relative feed value, it was observed that the varieties were better qualfied than the populations. It is concluded that the populations of Servi, Mutluca, Garip, Sarıçiçek-1 and Bagliisa can be used in breeding studies especially to obtain genetic progress in yield of alfalfa for feed and bioenergy production. For the genetic improvement of current genotypes with higher crude protein ratio, Kumgecit, Küçüktekören and Şenköy-1 populations can be used as a source. This study showed that, East Anatolia region is not just live-conserving highly diversified species but also covering special intra-species genetic diversity in microclimatic zones of Turkey to be used to improve the global forage and bioenergy cropproduction.

Salt Tolerance Associated With Molecular Markers in Alfalfa

Background: Breeding for salinity tolerance in open-pollinated crops depends on broad genetic variation in order to select for vigorous plants under salinity stress. Objective: To compare the yield of some local alfalfa cultivars under saline and non-saline soils and to develop molecular genetic markers associated with salt tolerance using RAPD and ISSR analysis, thereby providing a basis for alfalfa salt-tolerance breeding and research. Methods: A two years field trial was carried out during 2013/14 and 2014/15 in Galbana Village at Sahl El-Tina site., North Sinai Governorate with 13 cuts after establishing period. Three local parental cultivars, nine selected populations for salt stress under different stress levels (three initial EC’s: 8.73, 10.63 and 12.43 dSm-1), a new tolerant pop, and three exotic varieties were included in the experiment under initial EC’s (10.83). Results: Under Egyptian conditions, local cultivars: Siwa and Ismaelia were qualified as more adapted to salinity stress conditions than the exotic cultivars. New tolerant pop. ranked as the top yielding across all tested parental populations followed by Siwa and Ismaelia tolerant selected populations. New valley population had the lowest fresh, dry and protein yield overall studied populations. The tolerant selected populations were out yielded than their parental cultivars. A total of 16 alfalfa populations were analyzed at the molecular level to develop molecular markers associated with salt tolerance using seven RAPD and five ISSR primers. All primers succeeded to generate reproducible polymorphic DNA products. RAPD primers produced eight positive specific markers and six negative specific markers for salt tolerance in alfalfa population Sinai-1, while ISSR primers produced 12 positive specific markers and six negative specific markers for salt tolerance in alfalfa. The dendrograms were generated using pooled RAPD, ISSR, and the combined analysis of their data divided the alfalfa populations into two main clusters. The first cluster consisted of population Sinai 1 alone, while the second one contains all other evaluated populations. Conclusion: The new tolerant pop. could be considered as a new promising population and more adapted to salt stress.

Injury Indicator of Glyphosate to Alfalfa as affected by Recurrent Selection

In Egypt, alfalfa represts a suitable choice for forage cultivation expansion, since, the available land and water are oflower quality. The early seeding stage of alfalfa is the most val near able to weed competition. Research results regardingimprovement of alfalfa tolerance to glyphosate in Egypt is relatively scare. The recent study was an attempt to tracevariability in glyphosate tolerance of alfalfa germplasm. The improvement in tolerance due to recurrent selection was alsoconsidered. Alfalfa plant materials (Medicago sativa,L. ) used in that recent study were five base populations .Two cyclesof recurrent selection for Glyphosate tolerance were imposed on each base population. Evaluation of selected cycles (C1and C2) along with base populations (C0) was carried-out for each population as a split plot design with Glyphosatetreatment (+ and -) as main plots and populations (C0, C1 and C2) as a sub –plots. Glyphosate treated plots were evaluatedfor injury characters, i.e.; total chlorophyll, injury level, percent of death and shikimic acid content.Significant (p≥0.01) variations were detected among the studied alfalfa population. Also, the recorded values for allinjury indicator characters significantly varied among selection cycles. In the meantime, the interactions between thestudied population and selection cycles were significant (p ≥0.05). Chlorophyll content expressed as units was notchanged after one cycle of selection (30.22 and 29.15 spade for base population (C0) and first cycle of selection (C1) as anaverage over the studied population, respectively). While, the second cycle of selection resulted in significantly higherlevel of total chlorophyll content (34.51 spade). This might indicates that tolerance to glyphosate was associated to higherchlorophyll content. The value of injury level decreased in both of Siwa and Hasawi populations after the first cycle ofselection to glyphosate tolerance(-19.51 and -13.22%, respectively). Meanwhile, the progress of selection for glyphosatetolerance in alfalfa populations, gave a substantial decrease in value of injury level in all studied populations, except for,Siwa population that recorded an increase in value of injury level (-47.05, -44.44, -40.91 and -4.35 percent of therespective value recorded for injury level at the first cycle of selection in C.U.F101, Baladi 1, Sirivar and Hasawipopulations, respectively).Change in shikimic acid content represented by a decrease reached -35.05, -22.99, -5.49 and -4.26% in Siwa, Baldi 1, C.U.F 101 and Sirivar populations, respectively, after the first cycle of selection for glyphosatetolerance.Only Hasawi population recorded an increase in shikimic acid content reached +251.8% relative to base population.While, after the second cycle of selection an increase in shikimic acid content reached +63.60 and +4.688% for C.U.F101and Baldi1 populations relative to (C1). Sharing genes among tolerant individuals, increase the frequency of genesresponsible for tolerance, consequently expressing higher levels of cide- tolerance. The recent results assume thepossibility of obtaining glyphosate tolerant alfalfa population depending on frequent cycles of recurrent selection.

Genetic Loci Associated with Salt Tolerance in Advanced Breeding Populations of Tetraploid Alfalfa Using Genome-Wide Association Studies.

Many agricultural lands in the western United States consist of soil with high concentrations of salt, which is detrimental to alfalfa ( L.) growth and production, especially in the region where water resource is limited. Developing alfalfa varieties with salt tolerance is imperative for sustainable production under increasing soil salinity. In the present study, we used advanced alfalfa breeding populations and evaluated five traits related to salt tolerance including biomass dry weight (DW) and fresh weight (FW), plant height (PH), leaf relative water content (RWC), and stomatal conductance (SC) under control and salt stress. Stress susceptibility index (SSI) of each trait and single-nucleotide polymorphism (SNP) markers generated by genotyping-by-sequencing (GBS) were used for genome-wide association studies (GWAS) to identify loci associated with salt tolerance. A total of 53 significant SNPs associated with salt tolerance were identified and they were located at 49 loci through eight chromosomes. A Basic Local Alignment Search Tool (BLAST) search of the regions surrounding the SNPs revealed 21 putative candidate genes associated with salt tolerance. The genetic architecture for traits related to salt tolerance characterized in this report could help in understanding the genetic mechanism by which salt stress affects plant growth and production in alfalfa. The markers and candidate genes identified in the present study would be useful for marker-assisted selection (MAS) in breeding salt-tolerant alfalfa after validation of the markers.

Features of root system morphology in alfalfa populations

Features of root system morphology in alfalfa populations

Distribution and Productivity of Naturalized Alfalfa in Mixed-Grass Prairie

Alfalfa (Medicago sativa L.) is an important forage and conservation crop in North America but occurrences of naturalized alfalfa in rangelands are rare. A naturalized population of yellow-flowered alfalfa in mixed-grass prairie on the Grand River National Grassland in South Dakota has potential agricultural value for the region. Despite this value, the distribution pattern of this alfalfa among and within native plant communities in the northern Great Plains is unknown. Field studies were conducted from 2003 through 2006 along topographic positions at two sites where yellow-flowered alfalfa was naturalized to evaluate the relationships of yellow-flowered alfalfa on biomass production, cover, species diversity, and alfalfa seedbank distribution characteristics. High yellow-flowered alfalfa cover (>50%) was associated with increased total biomass and occurred exclusively in swales and toeslopes that had silty loam soils. However, species diversity and non-alfalfa biomass were reduced when yellow-flowered alfalfa cover was high. Yellow-flowered alfalfa cover was lower and species richness was higher on backslopes and shoulder areas where sandy loam soils were present. A strong positive linear association existed between yellow-flowered alfalfa cover and alfalfa seedbank density (r values ranged from 0.76 to 0.82, P < 0.0001). Greater than 99% of the seeds were viable but germination rate was only 4%, indicating a high percentage of hard seed in this alfalfa population. Naturalized yellow-flowered alfalfa was a dominant component of a stable, low diversity plant community composed of mainly introduced species in rich soils of swales/toeslopes that contributed to forage production and quality in mixed-grass prairie in the northern Great Plains.

Značaj izbora sorte u intenzivnoj proizvodnji lucerke

Alfalfa is an autotetraploid, perennial forage crop adapted to different environments and management systems. Trial with 12 alfalfa populations was established in spring of 2014. The research involved 9 commercial alfalfa varieties from IFVCNS, Serbia, and included 3 experimental populations in the final phase of breeding program. The main objectives of this paper were to examine the impact of variety selection on alfalfa yield and plant height in intensive cutting management in order to define harvesting strategies (using 6 and 5 cuts per season), with main goal to maximize profit on alfalfa farms in Serbia and Southeast Europe. Our study clearly demonstrates that there is genetic potential in some Serbian varieties (NS Sila, Nera, NS Jelena, and Banat VS) for use in intensive cutting systems with 6 cuts per year that can meet farmers' needs in conventional or organic type of alfalfa hay production.This research represents an initial guideline for the alfalfa variety selection in intensive cutting management systems in Serbia and Southeast Europe.

Effects of aluminium on the root activity, organic acids and free proline accumulation of alfalfa grown in nutrient solution

ABSTRACT The effects of elevated aluminium (Al) concentrations on parameters indicating Al toxicity and Al detoxification were evaluated in two alfalfa populations from different acidic soil environment. Plants were grown in nutrient solutions at pH 4.5, 5.5 and 6.0, with different levels of Al contamination for 30 days. Shoot heights and root activity were significantly decreased in the Al treatment while free proline concentration was significantly increased. Furthermore, citric acid and oxalic acid concentrations tend to increase with increasing Al concentration. Different responses were also observed between the two populations. Shoot height, free proline concentration and root activity were significantly higher for alfalfa plants collected from an acidic soil environment. These plants also exhibited higher concentrations of citric and oxalic acids when exposed to 100 μM Al at pH 4.5. Overall, the results indicate that alfalfa plants grown on acidic soils might develop mechanisms to be less affected by high Al concentration.

Evaluation of Alfalfa Swards in the Conditions of Middle Balkan Mountains

One of the most effective measures used to enhance natural grasslands in mountain and semi-mountain conditions is the inclusion of species such as alfalfa which is characterized by increased productivity, stability and adaptability. Thus, a comparative study of 3 varieties (‘Pleven 6’, ‘Prista 2’, ‘Multifoliate’) and 2 local populations (LP1, LP2) of alfalfa was conducted in the semi-mountain conditions of the Middle Balkan Mountains. The complex evaluation, comprising productivity and parameters of stability and adaptability, determined the sward of local population LP1, followed by varieties ‘Prista 2’ and ‘Pleven 6’ as the most suitable for cultivation in the Middle Balkan Mountains. They can be used successfully to enhance the composition of natural grasslands. The swards of species, such as birdsfoot trefoil and red clover, which were traditionally grown and typical for the Middle Balkan Mountains, were characterized by lower productivity, stability and adaptability respectively.

Field Assessment of Alfalfa Populations Recurrently Selected for Stem Cell Wall Digestibility

Genetic variability for stem cell wall (CW) digestibility could be exploited to improve rumen‐fermentable energy in alfalfa (Medicago sativa L.) forage. We evaluated in the field the response to recurrent selection for stem CW digestibility in alfalfa. Digestibility was assessed as the concentration of glucose released after enzymatic hydrolysis of fiber (enzyme‐released glucose, ERG). Two initial cultivars, 54V54 and Orca, and populations obtained after successive cycles of divergent selection for stem CW digestibility (D−1, D−2, D+1, and D+2) were established at three field sites in north, central, and south of Québec. Field trials conducted over two growing seasons showed that populations obtained after two selection cycles (D+2) had significantly higher CW digestibility (+20.7 mg ERG g−1 CW) than initial cultivars (average of 13% improvement of digestibility). The D+2 populations did not differ from the initial cultivars with regard to biomass yield, winter survival, and stem water soluble‐carbohydrate concentration. Increases of ERG concentrations were observed in response to each selection cycle, and broad‐sense heritability highlights a moderate control of genetic factors over environmental factors for CW digestibility. Recurrent selection for stem CW digestibility is a valuable approach to increase fermentable energy in alfalfa forage and improve N utilization by ruminants.

Variations in leaf gas exchange, chlorophyll fluorescence and membrane potential of Medicago sativa root cortex cells exposed to increased salinity: The role of the antioxidant potential in salt tolerance

Salinity is one of the most serious agricultural problems that adversely affects growth and productivity of pasture crops such as alfalfa. In this study, the effects of salinity on some ecophysiological and biochemical criteria associated with salt tolerance were assessed in two Moroccan alfalfa (Medicago sativa L.) populations, Taf 1 and Tata. The experiment was conducted in a hydro-aeroponic system containing nutrient solutions, with the addition of NaCl at concentrations of 100 and 200 mM. The salt stress was applied for a month. Several traits in relation to salt tolerance, such as plant dry biomass, relative water content, leaf gas exchange, chlorophyll fluorescence, nutrient uptake, lipid peroxidation and antioxidant enzymes, were analyzed at the end of the experiment. The membrane potential was measured in root cortex cells of plants grown with or without NaCl treatment during a week. The results indicated that under salt stress, plant growth and all of the studied physiological and biochemical traits were significantly decreased, except for malondialdehyde and H2O2 contents, which were found to be increased under salt stress. Depolarization of membrane root cortex cells with the increase in external NaCl concentration was noted, irrespective of the growth conditions. The Tata population was more tolerant to high salinity (200 mM NaCl) and its tolerance was associated with the ability of plants to maintain adequate levels of the studied parameters and their ability to overcome oxidative stress by the induction of antioxidant enzymes, such as guaiacol peroxidase, catalase and superoxide dismutase.