From Genes to Stress Response: Genomic and Transcriptomic Data Suggest the Significance of the Inositol and Raffinose Family Oligosaccharide Pathways in Stylosanthes scabra, Adaptation to the Caatinga Environment.

S. scabra is an important forage and extremophilic plant native to the Brazilian Caatinga semiarid region. It has only recently been subjected to omics-based investigations, and the generated datasets offer insights into biotechnologically significant candidates yet to be thoroughly examined. INSs (inositol and its derivatives) and RFO (raffinose oligosaccharide family) pathways emerge as pivotal candidates, given their critical roles in plant physiology. The mentioned compounds have also been linked to negative impacts on the absorption of nutrients in mammals, affecting overall nutritional intake and metabolism. Therefore, studying these metabolic pathways is important not just for plants but also for animals who depend on them as part of their diet. INS and RFO pathways in S. scabra stood out for their abundance of identified loci and enzymes. The enzymes exhibited genomic redundancy, being encoded by multiple loci and various gene families. The phylogenomic analysis unveiled an expansion of the PIP5K and GolS gene families relative to the immediate S. scabra ancestor. These enzymes are crucial for synthesizing key secondary messengers and the RFO precursor, respectively. Transcriptional control of the studied pathways was associated with DOF-type, C2H2, and BCP1 transcription factors. Identification of biological processes related to INS and RFO metabolic routes in S. scabra highlighted their significance in responding to stressful conditions prevalent in the Caatinga environment. Finally, RNA-Seq and qPCR data revealed the relevant influence of genes of the INS and RFO pathways in the S. scabra response to water deprivation. Our study deciphers the genetics and transcriptomics of the INS and RFO in S. scabra, shedding light on their importance for a Caatinga-native plant and paving the way for future biotechnological applications in this species and beyond.

Comparative analysis of codon usage patterns in the chloroplast genomes of nine forage legumes.

Leguminosae is one of the three largest families of angiosperms after Compositae and Orchidaceae. It is widely distributed and grows in a variety of environments, including plains, mountains, deserts, forests, grasslands, and even waters where almost all legumes can be found. It is one of the most important sources of starch, protein and oil in the food of mankind and also an important source of high-quality forage material for animals, which has important economic significance. In our study, the codon usage patterns and variation sources of the chloroplast genome of nine important forage legumes were systematically analyzed. Meanwhile, we also constructed a phylogenetic tree based on the whole chloroplast genomes and protein coding sequences of these nine forage legumes. Our results showed that the chloroplast genomes of nine forage legumes end with A/T bases, and seven identical high-frequency (HF) codons were detected among the nine forage legumes. ENC-GC3s mapping, PR2 analysis, and neutral analysis showed that the codon bias of nine forage legumes was influenced by many factors, among which natural selection was the main influencing factor. The codon usage frequency showed that the Nicotiana tabacum and Saccharomyces cerevisiae can be considered as receptors for the exogenous expression of chloroplast genes of these nine forage legumes. The phylogenetic relationships of the chloroplast genomes and protein coding genes were highly similar, and the nine forage legumes were divided into three major clades. Among the clades Melilotus officinalis was more closely related to Medicago sativa, and Galega officinalis was more closely related to Galega orientalis. This study provides a scientific basis for the molecular markers research, species identification and phylogenetic studies of forage legumes. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-024-01421-0.

Inclusion of Sainfoin in the Concentrate of Finishing Lambs: Fatty Acid Profiles of Rumen, Plasma, and Muscle.

The effects of sainfoin inclusion (Onobrychis viciifolia) in the finishing concentrate for light lambs on the fatty acid (FA) composition of the ruminal digesta, plasma, and meat were evaluated. Twenty-six weaned male lambs were divided into three groups and fed individually ad libitum for 40 days with one of three concentrates differing in the level of sainfoin inclusion: 0% (0SF), 20% (20SF), and 40% (40SF). The rumen digesta showed an increase in C18:3 n-3 concentration and a decrease in C18:1 t10 concentration when sainfoin was included in the concentrate regardless of the level of inclusion. However, the highest C18:1 t11 and the lowest C18:2 n-6 proportions were obtained only in the 40SF rumen, showing a stronger t11 biohydrogenation pathway. In plasma, most effects were associated with changes in the levels of polyunsaturated FA (PUFA) n-3. The meat FA profile of 40SF lambs presented higher percentages of PUFA n-3 and CLA c9,t11 and a lower PUFA n-6/PUFA n-3 ratio compared with those from 0SF and 20SF diets because of the potentiation of the ruminal t11 pathway. Inclusions of 20 and 40% sainfoin both showed beneficial effects on meat quality; furthermore, these effects were most marked in the 40% sainfoin diet.

Influences of peanut hull-derived biochar, Trichoderma harzianum and supplemental phosphorus on hairy vetch growth in Pb- and Zn-contaminated soil.

In the present study, in order to improve the growth performance of hairy vetch (Vicia villosa Roth., Local landrace from Ardabil, Iran) seedlings grown in the soil contaminated with heavy metals Pb and Zn, our attention was directed toward the application of biochar, inoculation with conidial suspension of Trichoderma harzianum Rifai-T22 and management of phosphorus (P) nutrition. Heavy metal toxicity reduced leaf greenness, membrane stability index, maximum quantum yield of PSΙΙ (Fv/Fm), P concentration and uptake in plant tissues and root and shoot biomass, but increased Pb and Zn concentration and uptake in root and leaf, H2O2 and malondialdehyde content and CAT and POX activity in the leaves. The application of biochar, inoculation with Trichoderma fungus and P supplementation increased the shoot P content, which might contribute to the alleviation of P insufficiency and a subsequent elevation in P transfer to aboveground biomass, and eliminated the toxicity of heavy metal on hairy vetch plants, which was revealed in reducing oxidative stress and enhancing plant growth performance. The biochar considerably increased Zn immobilization, while being able to slightly stabilize Pb. Co-application of Trichoderma and 22 mg P/kg soil (22P) increased the concentration and uptake of Zn in the roots and decreased the translocation of this element to the shoots, especially when biochar was not amended. Although the biochar and P inputs could compensate the negative Trichoderma effects, the results suggested that biochar application in combination with fungal inoculation and 22-P supplementation could not only increase hairy vetch growth performance but also decline heavy metal uptake to ensure the production of a forage crop in soils polluted with heavy metals based on the nutritional standards of livestock.

Exploring the differences between sole silages of gramineous forages and mixed silages with forage legumes using 16S/ITS full-length sequencing.

Background/Objective: Silage characteristics of grass materials directly affect their silage qualities. To expand the source of silage raw materials and develop mixed silages underlined by exploring the positive interactions between forage grasses and legumes, three gramineous grasses, Napier grass (Pennisetum purpureum), king grass (Pennisetum sinese), and forage maize (Zea mays) were separately mixed ensiled with a combination of four forage legumes including Medicago sativa, Vicia villosa, Vicia sativa, and Trifolium repens. Methods: The chemical composition and fermentation quality of the mixed silages were analyzed and compared with those of the sole silages of these three grasses, as well as the diversity of microbial communities, through the 16S/ITS full-length sequencing. Results: The results showed that the inclusion of forage legumes could somewhat improve the fermentation quality, as indicated by significantly (p < 0.05) higher crude protein and lactic acid contents while lower neutral detergent fiber, acid detergent fiber contents and pH values, compared with the sole silages. Among the three types of mixed silages, the mixed king grass had the highest dry matter and crude protein content as well as lowest neutral detergent fiber and acid detergent fiber content. Meanwhile, the bacterial and fungal communities in the mixed silages were influenced by increased the relative abundance of lactic acid bacteria, which inhibited the proliferation of undesirable bacteria, such as Hafnia alvei, Enterobacter cloacae, and Serratia proteamaculanss. Co-occurrence networks identified 32 nodes with 164 positive and 18 negative correlations in bacteria and 80 nodes with two negative and 76 positive correlations in fungi during fermentation. Conclusion: Inclusion of forage legume to grasses can improve the fermentation quality and optimize the structure of microbial community, which appears to be a feasible strategy to enhance the forage resource utilization.

Abiotic Stress Tolerance of Coastal Accessions of a Promising Forage Species, Trifolium fragiferum.

Crop wild relatives are valuable as a genetic resource to develop new crop cultivars, better adapted to increasing environmental heterogeneity and being able to give high quality yields in a changing climate. The aim of the study was to evaluate the tolerance of different accessions of a crop wild relative, Trifolium fragiferum L., from coastal habitats of the Baltic Sea to three abiotic factors (increased soil moisture, trampling, cutting) in controlled conditions. Seeds from four accessions of T. fragiferum, collected in the wild, were used for experiments, and cv. 'Palestine' was used as a reference genotype. Plants were cultivated in asymbiotic conditions of soil culture. Treatments were performed in a quantifiable way, with three gradations for soil moisture (optimum, waterlogged, flooded) and four gradations for both trampling and cutting. All accessions had relatively high tolerance against increased soil moisture, trampling, and cutting, but significant accession-specific differences in tolerance to individual factors were clearly evident, indicating that the studied wild accessions represented different ecotypes of the species. Several wild accessions of T. fragiferum showed stress tolerance-related features superior to these of cv. 'Palestine', but TF1 was the most tolerant accession, with a very high score against both waterlogging and cutting, and a high score against trampling.

The Fate of Tannins from Birdsfoot Trefoil and Their Effect on the Nitrogen Balance in Growing Lambs Fed Diets Varying in Protein Level.

Two experimental periods were employed to investigate the fate of ingested CT from BT and their effects on the intake, digestibility, and N balance in lambs fed diets differing in CP levels. In period 1, 24 lambs were fed a basal diet either treated with polyethylene glycol (PEG+) to deactivate CT or without polyethylene glycol (PEG-). In period 2, the same lambs were used in a 2 × 2 factorial design and fed either the basal diet (BP) or a high protein diet (HP), again treated with or without PEG. In both experimental periods, feeding lambs diets without PEG caused a reduction in the dry matter (DM) intake and an increase in the DM digestibility. Urinary and total N excretion decreased in lambs fed diets without PEG, but only in absolute terms and not in relation to the N intake. The total N intake, total N excretion, and body N retention were higher with a higher dietary CP level. Related to the CT intake, less soluble and protein-bound CT were excreted by lambs fed diets without PEG, and more protein-bound and fiber-bound CT were excreted by lambs fed BP diets. Regardless of the PEG treatment and CP level, not all CT that are ingested are also excreted. The effect of PEG treatment on the N excretion pathway was independent of the CP level.

Improved feeding and forages at a crossroads: Farming systems approaches for sustainable livestock development in East Africa.

Dairy development provides substantial potential economic opportunities for smallholder farmers in East Africa, but productivity is constrained by the scarcity of quantity and quality feed. Ruminant livestock production is also associated with negative environmental impacts, including greenhouse gas (GHG) emissions, air pollution, high water consumption, land-use change, and loss of biodiversity. Improved livestock feeding and forages have been highlighted as key entry point to sustainable intensification, increasing food security, and decreasing environmental trade-offs including GHG emission intensities. In this perspective article, we argue that farming systems approaches are essential to understand the multiple roles and impacts of forages in smallholder livelihoods. First, we outline the unique position of forages in crop-livestock systems and systemic obstacles to adoption that call for multidisciplinary thinking. Second, we discuss the importance of matching forage technologies with agroecological and socioeconomic contexts and niches, and systems agronomy that is required. Third, we demonstrate the usefulness of farming systems modeling to estimate multidimensional impacts of forages and for reducing agro-environmental trade-offs. We conclude that improved forages in East Africa are at a crossroads: if adopted by farmers at scale, they can be a cornerstone of pathways toward sustainable livestock systems in East Africa.

The First Genetic Map for a Psoraleoid Legume (Bituminaria bituminosa) Reveals Highly Conserved Synteny with Phaseoloid Legumes.

We present the first genetic map of tedera (Bituminaria bituminosa (L.) C.H. Stirton), a drought-tolerant forage legume from the Canary Islands with useful pharmaceutical properties. It is also the first genetic map for any species in the tribe Psoraleeae (Fabaceae). The map comprises 2042 genotyping-by-sequencing (GBS) markers distributed across 10 linkage groups, consistent with the haploid chromosome count for this species (n = 10). Sequence tags from the markers were used to find homologous matches in the genome sequences of the closely related species in the Phaseoleae tribe: soybean, common bean, and cowpea. No tedera linkage groups align in their entirety to chromosomes in any of these phaseoloid species, but there are long stretches of collinearity that could be used in tedera research for gene discovery purposes using the better-resourced phaseoloid species. Using Ks analysis of a tedera transcriptome against five legume genomes provides an estimated divergence time of 17.4 million years between tedera and soybean. Genomic information and resources developed here will be invaluable for breeding tedera varieties for forage and pharmaceutical purposes.

Stomatal Development and Conductance of a Tropical Forage Legume Are Regulated by Elevated [CO2] Under Moderate Warming.

The opening and closing of stomata are controlled by the integration of environmental and endogenous signals. Here, we show the effects of combining elevated atmospheric carbon dioxide concentration (eCO 2; 600 µmol mol-1) and warming (+2°C) on stomatal properties and their consequence to plant function in a Stylosanthes capitata Vogel (C3) tropical pasture. The eCO 2 treatment alone reduced stomatal density, stomatal index, and stomatal conductance (gs ), resulting in reduced transpiration, increased leaf temperature, and leading to maintenance of soil moisture during the growing season. Increased CO2 concentration inside leaves stimulated photosynthesis, starch content levels, water use efficiency, and PSII photochemistry. Under warming, plants developed leaves with smaller stomata on both leaf surfaces; however, we did not see effects of warming on stomatal conductance, transpiration, or leaf water status. Warming alone enhanced PSII photochemistry and photosynthesis, and likely starch exports from chloroplasts. Under the combination of warming and eCO 2, leaf temperature was higher than that of leaves from the warming or eCO 2 treatments. Thus, warming counterbalanced the effects of CO2 on transpiration and soil water content but not on stomatal functioning, which was independent of temperature treatment. Under warming, and in combination with eCO 2, leaves also produced more carotenoids and a more efficient heat and fluorescence dissipation. Our combined results suggest that control on stomatal opening under eCO 2 was not changed by a warmer environment; however, their combination significantly improved whole-plant functioning.

Bromatological characteristics of Macrotyloma axillare as a function of combined supply of phosphorus and calcium / Características bromatológicas de Macrotyloma axillare em função do suprimento combinado de fósforo e cálcio

The supply of nutrients to forage legumes is significant for their nutritional quality. The study aimed to evaluate the bromatological characteristics of the legume Macrotyloma axillare in response to the combined application of phosphorus and calcium. The study was conducted in a greenhouse on a Red Yellow Ultisol. A fractionated 52 factorial was used, with 13 different combinations of phosphorus and calcium application rates (P-Ca): 0-0; 0-20; 0-40; 100-10; 100-30; 200-0; 200-20; 200-40; 300-10; 300-30; 400-0; 400-20; and 400-40 mg dm-3. Experimental units were set in a randomized block design, with four replications. Neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose, cellulose, lignin, and crude protein (CP) in the leaves and branches were determined in two harvests. In both harvests of the legume we observed that the ADF, hemicellulose, cellulose, and lignin contents in the leaves did not show isolated or combined responses to phosphorus and calcium rates. It was concluded that the combined supply of phosphorus and calcium did not interfere in the nutritional quality of the legume. Calcium supplied alone interfered only the NDF content and phosphorus supplied of the CP of the leaves. Phosphorus rates of 31.5 mg dm-3 and 28.2 mg dm-3 were responsible for the lower NDF content in the leaves and the higher hemicellulose content in the branches, respectively.(AU)

O fornecimento de nutrientes para as leguminosas forrageiras é importante para sua qualidade nutricional. O estudo objetivou avaliar as características bromatológicas da Macrotyloma axillare em resposta a aplicação combinada de doses de fósforo e cálcio. O estudo foi desenvolvido em uma casa de vegetação sob um Argissolo Vermelho-Amarelo. Utilizou-se um esquema fatorial 52 fracionado, com 13 combinações diferentes das doses de fósforo e cálcio (P-Ca): 0-0, 0‒40, 0‒80, 15‒20, 15‒60, 30‒0, 30‒40, 30‒80, 45‒20, 45‒60, 60‒0, 60‒40, e 60‒80 mg dm-3. As unidades experimentais foram distribuídas em delineamento de blocos ao acaso, com quatro repetições. Determinou-se fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), hemicelulose, celulose, lignina e proteína bruta (PB) das folhas e ramos em dois cortes. Nos dois cortes da leguminosa observou-se que os teores de FDA, hemicelulose, celulose e lignina das folhas não apresentaram respostas isoladas ou combinadas às doses de fósforo e cálcio. Concluiu-se que o fornecimento combinado de fósforo e cálcio não influenciou na qualidade nutricional da leguminosa. O fornecimento isolado de cálcio interferiu somente no teor de FDN e fornecimento de fósforo na PB das folhas. As doses de fósforo de 31,5 mg dm-3 e 28,2 mg dm-3 foram responsáveis pelo menor teor de FDN nas folhas e pelo maior teor de hemicelulose nos ramos, respectivamente.(AU)

Relationships between Structures of Condensed Tannins from Texas Legumes and Methane Production During In Vitro Rumen Digestion.

Previous studies showed that a series of purified condensed tannins (CTs) from warm-season perennial legumes exhibited high variability in their modulation of methane production during in vitro rumen digestion. The molecular weight differences between these CTs did not provide correlation with either the in vitro CH4 production or the ability to precipitate bovine serum albumin. In an effort to delineate other structure-activity relationships from these methane abatement experiments, the structures of purified CTs from these legumes were assessed with a combination of methanolysis, quantitative thiolysis, ¹H-13C HSQC NMR spectroscopy and ultrahigh-resolution MALDI-TOF MS. The composition of these CTs is very diverse: procyanidin/prodelphinidin (PC/PD) ratios ranged from 98/2 to 2/98; cis/trans ratios ranged from 98/2 to 34/66; mean degrees of polymerization ranged from 6 to 39; and % galloylation ranged from 0 to 75%. No strong correlation was observed between methane production and the protein precipitation capabilities of the CT towards three different proteins (BSA, lysozyme, and alfalfa leaf protein) at ruminal pH. However, a strong non-linear correlation was observed for the inhibition of methane production versus the antioxidant activity in plant sample containing typical PC- and PD-type CTs. The modulation of methane production could not be correlated to the CT structure (PC/PD or cis/trans ratios and extent of galloylation). The most active plant in methane abatement was Acacia angustissima, which contained CT, presenting an unusual challenge as it was resistant to standard thiolytic degradation conditions and exhibited an atypical set of cross-peak signals in the 2D NMR. The MALDI analysis supported a 5-deoxy flavan-3-ol-based structure for the CT from this plant.

From model to crop: functional characterization of SPL8 in M. truncatula led to genetic improvement of biomass yield and abiotic stress tolerance in alfalfa.

Biomass yield, salt tolerance and drought tolerance are important targets for alfalfa (Medicago sativa L.) improvement. Medicago truncatula has been developed into a model plant for alfalfa and other legumes. By screening a Tnt1 retrotransposon-tagged M. truncatula mutant population, we identified three mutants with enhanced branching. Branch development determines shoot architecture which affects important plant functions such as light acquisition, resource use and ultimately impacts biomass production. Molecular analyses revealed that the mutations were caused by Tnt1 insertions in the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 8 (SPL8) gene. The M. truncatula spl8 mutants had increased biomass yield, while overexpression of SPL8 in M. truncatula suppressed branching and reduced biomass yield. Scanning electron microscopy (SEM) analysis showed that SPL8 inhibited branching by directly suppressing axillary bud formation. Based on the M. truncatula SPL8 sequence, alfalfa SPL8 (MsSPL8) was cloned and transgenic alfalfa plants were produced. MsSPL8 down-regulated or up-regulated alfalfa plants exhibited similar phenotypes to the M. truncatula mutants or overexpression lines, respectively. Specifically, the MsSPL8 down-regulated alfalfa plants showed up to 43% increase in biomass yield in the first harvest. The impact was even more prominent in the second harvest, with up to 86% increase in biomass production compared to the control. Furthermore, down-regulation of MsSPL8 led to enhanced salt and drought tolerance in transgenic alfalfa. Results from this research offer a valuable approach to simultaneously improve biomass production and abiotic stress tolerance in legumes.

Effect of photoperiod prior to cold acclimation on freezing tolerance and carbohydrate metabolism in alfalfa (Medicago sativa L.).

Cold acclimation proceeds sequentially in response to decreases in photoperiod and temperature. This study aimed at assessing the impact of photoperiod prior to cold acclimation on freezing tolerance and related biochemical and molecular responses in two alfalfa cultivars. The fall dormant cultivar Evolution and semi-dormant cultivar 6010 were grown in growth chambers under different photoperiods (8, 10, 12, 14 or 16h) prior to cold acclimation. Freezing tolerance was evaluated as well as carbohydrate concentrations, levels of transcripts encoding enzymes of carbohydrate metabolism as well as a K-3dehydrin, before and after cold acclimation. The fall dormant cultivar Evolution had a better freezing tolerance than the semi-dormant cultivar 6010. The effect of photoperiod prior to cold acclimation on the level of freezing tolerance differed between the two cultivars: an 8h-photoperiod induced the highest level of freezing tolerance in Evolution and the lowest in 6010. In Evolution, the 8h-induced superior freezing tolerance was associated with higher concentration of raffinose-family oligosaccharides (RFO). The transcript levels of sucrose synthase (SuSy) decreased whereas those of sucrose phosphatase synthase (SPS) and galactinol synthase (GaS) increased in response to cold acclimation in both cultivars. Our results indicate that RFO metabolism could be involved in short photoperiod-induced freezing tolerance in dormant alfalfa cultivars.

Amendoim forrageiro manejado com baixos resíduos de pastejo por ovinos / Perennial peanut handled with low grazing waste by sheep

O objetivo do trabalho foi estudar o comportamento produtivo do amendoim forrageiro (Arachis pintoi cv. Amarillo) sob diferentes intensidades de pastejo por ovinos em ambiente rotativo. Os tratamentos corresponderam a quatro intensidades de pastejo (muito leniente - ML, leniente - L, moderado - M e severo - S) representadas pelas alturas de resíduo de 11,2; 8,4; 5,9 e 3,2cm, que foram alocadas segundo um delineamento inteiramente ao acaso, com quatro repetições. As variáveis estudadas no pré e no pós-pastejo foram: massa de forragem, percentual de folhas e caules e índice de área foliar. Ao final do experimento, foi calculada a massa de forragem total acumulada, a taxa de acúmulo e a massa de forragem desaparecida. Os dados foram submetidos à análise de variância e ao teste de comparação de médias de Tukey (P< 0,05). Foi verificado que a intensidade de pastejo modifica a composição dos componentes morfológicos e a massa de forragem acumulada pelo amendoim forrageiro, todavia o índice de área foliar no pré-pastejo não é alterado. O amendoim forrageiro não deve ser utilizado sob pastejo intenso. Intensidades de pastejo de moderada a muito leniente proporcionam maior massa de forragem pré-pastejo e total acumulada, associada a menores intervalos entre pastejos.(AU)

This research aimed to study the productive behavior of perennial peanut (Arachis pintoi cv. Amarillo) under different grazing intensities by sheep in a rotation environment. The treatments consisted of four grazing intensity levels (very lenient - VL, lenient - L, moderate - M, and severe - S) represented by the residues 11.2; 8.4; 5.9 and 3.2cm, and allocated randomly with four replications. The variables studied in the pre-grazing and post-grazing were: forage mass, percentage of leaves and stems and leaf area index. At the end of the experiment, total accumulated forage mass, accumulation rate, and mass of missing forage were calculated. The data was submitted to a variance analysis and comparison to a Tukey's test, with a 5% significance level. Grazing intensity was found to modify the composition of morphological components and the forage mass accumulated by peanuts; however, the leaf area index in pre-grazing remained constant. Perennial peanut should not be used under intensive grazing. Grazing intensity from moderate to very lenient provides greater mass of pre-grazing forage and total accumulated forage, combined with shorter intervals between grazing.(AU)

Pod, seed traits and cytotaxonomic studies of some Vicia narbonensis L. accessions (Fabaceae).

This study aimed to characterize eight accessions of Vicia narbonensis L. originated from different Mediterranean countries. The cytology of these species is rarely known despite the fact of its great socio-economical and ecological interest in these arid and semi-arid zones. This work aimed mainly to characterize the karyotype, morphological pod and seed traits of the species. Karyotypes of all accessions were similar to a diploid number of 2n = 2x = 14. All the accessions have submetacentric chromosomes with a secondary constriction attached to the long arm of pair VII close to the centromere. Variation in chromosome size was observed; it ranged from 5.86 µm to 7.62 µm. Indices of karyotype asymmetry were calculated as the total form percentage (TF%) and symmetric indices (Syi) which ranged from 33.75% to 35.42% and from 51.01% to 54.85%, respectively. The predominance of submetacentric chromosomes indicated that the karyotype is symmetrical and can be considered as primitive. However, the analysis of quantitative parameters measured on pods and seeds showed a significant variation between accessions. A relationship between centromeric index and the pod beak length was found. Estimation of phenotypic diversity using the Shannon diversity index (H') showed that the length, the seed color and the number of seeds per pod are the most polymorphic traits with respectively, H' = 0.92, 0.80 and 0.83. Cluster analysis of karyological, pod and seed traits showed four groups of accessions. This clustering is partially due to the geographical origin of the studied accessions. The variation in chromosome size, pod and seed traits could offer potentially valuable genetic resources for the improvement of V. narbonensis which is considered as neglected and underutilized crop species (NUCS).

Co-expression of NCED and ALO improves vitamin C level and tolerance to drought and chilling in transgenic tobacco and stylo plants.

Abscisic acid (ABA) regulates plant adaptive responses to various environmental stresses, while L-ascorbic acid (AsA) that is also named vitamin C is an important antioxidant and involves in plant stress tolerance and the immune system in domestic animals. Transgenic tobacco (Nicotiana tabacum L.) and stylo [Stylosanthes guianensis (Aublet) Swartz], a forage legume, plants co-expressing stylo 9-cis-epoxycarotenoid dioxygenase (SgNCED1) and yeast D-arabinono-1,4-lactone oxidase (ALO) genes were generated in this study, and tolerance to drought and chilling was analysed in comparison with transgenic tobacco overexpressing SgNCED1 or ALO and the wild-type plants. Compared to the SgNCED1 or ALO transgenic plants, in which only ABA or AsA levels were increased, both ABA and AsA levels were increased in transgenic tobacco and stylo plants co-expressing SgNCED1 and ALO genes. Compared to the wild type, an enhanced drought tolerance was observed in SgNCED1 transgenic tobacco plants with induced expression of drought-responsive genes, but not in ALO plants, while an enhanced chilling tolerance was observed in ALO transgenic tobaccos with induced expression of cold-responsive genes, but not in SgNCED1 plants. Co-expression of SgNCED1 and ALO genes resulted in elevated tolerance to both drought and chilling in transgenic tobacco and stylo plants with induced expression of both drought and cold-responsive genes. Our result suggests that co-expression of SgNCED1 and ALO genes is an effective way for use in forage plant improvement for increased tolerance to drought and chilling and nutrition quality.

Interrelations between herbage yield, α-tocopherol, ß-carotene, lutein, protein, and fiber in non-leguminous forbs, forage legumes, and a grass-clover mixture as affected by harvest date.

Pastures with diverse botanical composition may enhance animal-derived product quality. A recent study demonstrated high vitamin concentrations and yields in some forb species. The objectives of the present study were to investigate interrelations between herbage yields, vitamin concentrations, protein and fiber contents and analyze the effect of harvest date. We hypothesized that interrelations would be similar across investigated forage species. Four nonleguminous forbs: salad burnet (Sanguisorba minor), caraway (Carum carvi), chicory (Cichorium intybus), and ribwort plantain (Plantago lanceolata), three legumes: yellow sweet clover (Melilotus officinalis), lucerne (Medicago sativa), and birdsfoot trefoil (Lotus corniculatus) and a perennial ryegrass (Lolium perenne)-white clover (Trifolium repens) mixture were sown in a field trial with two replicated and randomized blocks. Forage in 1.5 m × 9 m plots was grown in two consecutive years and cut four times per year (May-October). Analyses of variance were performed. In most herbages, α-tocopherol and ß-carotene were positively correlated as were ß-carotene and lutein; all vitamins were negatively correlated with fiber content and herbage yield. ß-Carotene was positively correlated with protein content. α-Tocopherol and ß-carotene contents were generally highest in October and lowest in July. Our results showed similar interrelationships in most investigated species, and we suggest that these species may be mixed when designing novel biodiverse mixtures for particular product quality characteristics.

Evaluation of the population dynamics of the forage legume (Lotus corniculatus), using matrix population models.

The population dynamics of perennial crop plants are influenced by numerous factors, including management practices. Conditions in the field vary from year to year, and matrix population models are useful for evaluating population behaviour in relation to environmental variability. In Missouri, the stand persistence of birdsfoot trefoil (Lotus corniculatus), a perennial legume, is often limited by disease and poor seed production. A stage-based, matrix population model was developed to evaluate the population dynamics of birdsfoot trefoil in relation to clipping treatment. The plant growth stages represented in the model were seeds, seedlings, mature vegetative and reproductive plants. Two phases of population growth were evaluated in clipped and unclipped stands. Establishment-phase populations were characterized by relatively high mortality and low reproduction. Elasticity analysis indicated that growth of these populations was most sensitive to the survival of vegetative plants. Mature vegetative plants and seeds comprised the majority of surviving individuals in clipped and unclipped populations, respectively; however, establishment-phase populations under both management treatments tended toward extinction. Populations in the post-establishment phase of growth were characterized by relatively low mortality and high reproduction. Population growth in this phase of growth was most sensitive to seed production, and most individuals in these populations were at the seed stage.