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In order to develop a high-efficiency and reproducible transformation protocol for Stylosanthes guianensis we assessed the biological and physical parameters affecting plant electroporation protoplasts. Energy input, as combinations of electric field strengths discharged by different capacitors, electroporation buffer and DNA form were evaluated. Transformation efficiency was assayed in vivo as transient reporter gene expression, using the GFP-coding gene mgfp5 driven by a CaMV 35S constitutive promoter. Energy input and electric field strength had a critical influence on transgene expression with higher transformation levels being achieved with 250 V.cm-1 discharged by 900 and 1000 muF capacitors. Linear plasmid DNA, the absence of chloride and the presence of calcium ions also increased transient gene expression, albeit not significantly.

Três espécies de leguminosas tropicais foram submetidas a níveis crescentes de saturação por bases com a finalidade de se determinar, sob condições de casa de vegetação, qual o nível que possibilita maior produção de matéria seca. Foram estabelecidos quatro tratamentos ou 10, 30, 50 e 70% de saturação por bases através da adição de óxido de cálcio e magnésio correspondentes a 0; 1,2; 2,4 e 3,6 t calcário/ha. O delineamento foi inteiramente ao acaso com cinco repetições. O resultado da análise de solo aos vinte dias de incubação mostrou elevação nos valores de pH e saturação por bases, bem como diminuição nos teores de AI3+ com a calagem. Máximas produções de matéria seca foram obtidas ao nível de 57% para soja-perene (Neonotonia wightii Lakey var. Tinaroo) e 35% para estilosantes (Stylosanthes guianensis Sw. cv. Bandeirante). O ponto de máxima produção não foi encontrado para macrotiloma (MacrotylomaaxillareVerdc.) cv. Guatá, em vista de terem sido observados acréscimos lineares até o maior nível de calagem usado. A elevação no nível de saturação por bases promoveu melhoria na nodulação da soja-perene quando foram observados aumentos lineares no número de nódulos e aumento no peso de nódulos até o nível de 49% de saturação por bases. Para o macrotiloma foram observados aumentos lineares no número e peso de nódulos.

O trabalho foi realizado na Seção de Agronomia de Plantas Forrageiras do Instituto de Zootecnia, Nova Odessa, SP, com o objetivo de estudar o comportamento morfofisiológico e agronômico de três acessos de Stylosanthes guianensis (NO 1336, NO 2262 e NO 2313) selecionados neste Instituto, comparando-os com o cv. Comercial Bandeirante. Esses acessos foram semeados em um solo Podzólico Vermelho-Amarelo, variação Laras. No período de 29/12/86 a 19/05/88 as plantas foram cortadas mecanicamente às alturas de 10, 20 e 30 cm do solo, sendo avaliadas as produções de matéria seca (MS) e proteína bruta (PB). No período de 30/10/89 a 04/05/90 foi analisada a persistência das plantas sob pastejo animal. Em casa de vegetação, plantas dos quatro acessos foram inoculadas com os fungos Colletotrichum gloeosporioides e C. dematium visando observar o desenvolvimento e a severidade das doenças nas plantas. Observou-se que 84 dias após a germinação, todos os acessos estavam perfeitamente estabelecidos, cobrindo 75%, ou mais, do solo. No período de menor disponibilidade de forragem e de nutrientes nas pastagens (período das secas), o acesso NO 1336 sobressaiu-se com produção de 2612kg de MS/ha e de PB de 473kg/ha. O efeito de altura de corte foi significativo na produção de MS e PB dos acessos, sendo considerada melhor a altura de 10cm. O esquema de cortes usado é recomendado para a exploração com manutenção da cobertura vegetal do solo. A geada e a incidência de doenças, tais como Colletotrichum gloeosporioides, C. dematium e. Alternaria tenui, foram fatores determinantes na persistência do S. guianensis, sendo que o pastejo não teve nenhuma influência.

Utilizaram-se sete carneiros, sem raça definida, fistulados no rúmen e duodeno, para avaliar o consumo e as digestibilidades aparentes totais e parciais de matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), extrato etéreo (EE), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), celulose (CEL) e hemicelulose (HCEL) do feno de Stylosanthes guianensis. Os animais receberam apenas feno de S. guianensis mais sal mineral como componentes da dieta. O fornecimento do feno foi ad libitum, sendo a quantidade calculada para permitir sobras de 20%. Utilizou-se óxido crômico como indicador para estimar a produção de fezes e o fluxo de digesta no duodeno. Os consumos de MS e MO do S. guianensis foram 67,71 e 64,70 g/kg0,75, respectivamente. As digestibilidades aparentes totais da MS, MO, PB, FDN e FDA foram 49,2, 51,3, 61,2, 42,0 e 42,7%, respectivamente. As digestibilidades aparentes ruminais da MS, MO, FDN e FDA foram 75,8, 84,7, 89,6 e 90,6%, respectivamente, em função do total digerido. A digestibilidade ruminal da PB foi 21,3%. Concluiu-se que o feno de S. guianensis, colhido em estádio de maturidade avançada, pode ser indicado para ruminantes, pois seu consumo é capaz de atender às necessidades energéticas de mantença já que seus valores, apesar de sua digestibilidade não ser elevada, são ligeiramente maiores do que os de outras forrageiras tropicais.Seven rumen and duodenal cannulated lambs were used to evaluate the intake and the total and the partial apparent digestibilities of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose (CEL) and hemicellulose (HCEL) of the Stylosanthes guianensis hay. The diet was composed by the hay of S. guianensis plus mineral salt. The hay was offered ad libitum with the refusals estimated for being 20%. Chromium oxide was used as an external marker, to estimate fecal production and digesta flow to the duodenum. The intake of DM and OM of S. guianensis were 67.71 and 64.70 g/kg0.75, respectively. The total apparent digestibilities of DM, OM, CP, NDF and ADF were 49.2, 51.3, 61.2, 42.0 and 42.7%, respectively. Ruminal apparent digestibilities of DM, OM, NDF and ADF were 75.8, 84.7, 89.64 and 90.6%, respectively, as a function of total apparent digestibilities. The ruminal digestibility of CP was 21.3%. The use of S. guianensis hay, harvested at advanced stage of maturity may be indicated for sheep, because its DM intake and digestibility allowed energy supply for their maintenance requirements.

Sete carneiros fistulados no rúmen e no duodeno foram alojados em gaiolas metabólicas e alimentados com feno de Stylosanthes guianensis à vontade. Foi empregada a técnica de sacos de náilon para determinação da degradabilidade in situ do feno, utilizando-se os tempos de 3, 6, 12, 24, 48 e 72 horas para as retiradas dos sacos do rúmen. A taxa de passagem dos sólidos foi determinada utilizando-se cromo mordante como indicador. Os valores de pH no líquido ruminal foram medidos nos tempos de 0, 2, 4, 6 e 8 horas após a alimentação e a concentração de amônia nos tempos de 0, 1, 3, 5, 7, 9 e 11 horas após a alimentação. A taxa de degradação da matéria seca (MS) foi de 8,5%/h, a degradabilidade potencial 38,1% e a degradabilidade efetiva 30,3%. A taxa de degradação da proteína bruta (PB) foi de 9,7%/h, a degradabilidade potencial 56,0% e a degradabilidade efetiva 47,5%. A celulose apresentou maior degradabilidade efetiva que a hemicelulose, com valores de 22,5 e 8,9%, respectivamente. A taxa de passagem dos sólidos foi 2,7%/h. O pH diminuiu linearmente à medida que os tempos de coleta aumentaram. Para o tempo de 5,13 horas após a alimentação, foi estimada a concentração máxima de amônia de 12,18mg/100ml. O feno de S. guianensis apresentou alta taxa de degradação e baixa degradabilidade ruminal da MS e PB.Seven rumen and duodenal cannulated lambs, were allocated in metabolic cages and were fed ad libitum with Stylosanthes guianensis hay. The in situ technique was used for determination of the degradability of the hay, at 3, 6, 12, 24, 48 and 72 hours of incubation. The passage rate of solids was determined using chromium mordant as external marker. The pH of the rumen liquid was measured at 0, 2, 4, 6 and 8 hours after feeding and the ammonia concentration at 0, 1, 3, 5, 7, 9 and 11 hours after feeding. The degradation rate, the potential degradability, and the effective degradability of dry matter (DM) were 8.5%/h, 38.1% and 30.3%, respectively. The degradation rate of crude protein (CP) was 9.7%/h, the potential degradability was 56.0% and the effective degradabilty was 47.5%. The cellulose presented larger effective degradability than hemicellulose, with the respective values of 22.5% and 8.9%. The passage rate for solids was 2.7%/h. The pH decreased linearly with time of rumen fluid sampling. For the time of 5.13 hours after feeding, the highest ammonia concentration (12.18 mg/100ml) was observed. The S. guinanensis hay showed high degradation rates and low ruminal degradability of DM and CP.

Most species of Stylosanthes (stylo) genus are important tropical pasture legumes with very versatile, widely adapted, and productive characteristics. These legumes are commercially used in various agricultural systems in many tropical and subtropical regions. However, the few molecular markers for the stylo species limit their genetic improvement. In this study, 36,558 expressed sequence tags (ESTs) have been de novo assembled using Illumina paired-end sequencing in Stylosanthes guianensis (Aubl.) Sw. to develop simple sequence repeat (SSR) markers. We searched these ESTs for SSRs and identified 4115 SSR loci from 3643 ESTs (9.96 %). Dinucleotide and trinucleotide repeat motifs were the most abundant types (30.50 and 50.33 %, respectively), whereas tetranucleotide, pentanucleotide, and hexanucleotide motifs represented <10 % of all SSRs. The motif AG/CT was the most abundant, accounting for 21.7 % of all SSRs. Moreover, 2008 SSR markers were developed using 1873 SSR-containing unigenes. A total of 115 EST-SSR markers located in the coding region were amplified using polymerase chain reaction to detect 29 S. guianensis accessions. Of these 115 markers, 96 produced reliable bands with expected sizes, and 81 markers were polymorphic, with 2-6 alleles among the 29 accessions. Analysis of the genetic diversity of all 29 accessions revealed similarity coefficients that ranged from 0.528 to 0.983. The EST-SSR markers developed in this study represent the first large-scale development of SSR markers for S. guianensis. These SSR markers will provide a valuable resource for genetic diversity studies, cultivar fingerprinting, construction of genetic maps, identification of quantitative trait loci for important traits, and molecular marker-assisted selection breeding in stylo species. [ABSTRACT FROM AUTHOR]

The effect of age of regrowth (21, 42, 63 and 84 d) on the dry matter yield (DMY), leaf proportion (LP) and nutritive value of cacahuatillo (Arachis pintoi), stylo (Stylosanthes guianensis), clitoria (Clitoria ternatea) and kudzu (Pueraria phaseoloides) was evaluated during the dry season (March-May) and rainy (June-August) of 2013. The DMY and neutral detergent fiber (NDF) increased with age, while the LP, protein (CP) and degradability decreased. Stylo and cacahuatillo recorded the highest DMY in both seasons; on average 5.5 and 7.5 t ha-1 at 84 d in dry and rainy season respectively. In both seasons, the highest and lowest LP were for cacahuatillo and stylo, respectively. High CP was recorded by clitoria and cacahuatillo in both seasons; greater than 14 g kg-1 DM even 84 d old. No significant variation was observed in CP from 42 d in the species. At 21 d, stylo (704.7 g kg-1 DM) in the dry season and kudzu (658.4 g kg-1 DM) in the rainy season had the largest NDF. There were no differences between species from 42 d. Cacahuatillo had the highest degradability (>700 g kg-1 DM) during its growth in both seasons. In clitoria, stylo and kudzu was just above 700 g kg-1 DM at 21 d, but from 42 d of age, degradability decreased. In conclusion, the age of regrowth that integrates DMY and better nutritional value is 42 d old in the legumes evaluated, regardless of the season of year. [ABSTRACT FROM AUTHOR]

Avaliaram-se os efeitos de doses de fósforo (0, 50, 100, 200 e 400 mg kg-1 de solo) e da inoculação de uma mistura de fungos micorrízicos arbusculares (FMAs) (Glomus etunicatum, Glomus clarum, Gigaspora margarita e Acaulospora scrobiculata) no acúmulo de nitrogênio, fósforo e no crescimento do estilosantes (Stylosanthes guianensis Aubl. sw.), capim-gordura (Melinis minutiflora Beauv.), capim-braquiária (Brachiaria decumbens Stapf.) e do cultivo misto com estilosantes e capim-gordura em solo degradado. O experimento foi desenvolvido em casa de vegetação, sendo realizados três cortes da parte aérea das plantas, com intervalo de 150 dias. As raízes foram coletadas no último corte. Verificou-se, na matéria seca da parte aérea (MSPA) e de raízes (MSR), no acúmulo de N e de P, resposta positiva a doses crescentes de P em todas as espécies estudadas. A inoculação de FMAs aumentou a MSPA, MSR e o acúmulo de N e P, e causou diferenciação da magnitude deste aumento entre as espécies. O estilosantes apresentou baixa colonização (4% em média), porém foi muito responsivo à inoculação de FMAs. O efeito da aplicação de P no acúmulo de N na MSPA foi favorecido pela inoculação de FMAs. O uso do capim-gordura, que não depende dos FMAs para alcançar o estabelecimento adequado, pode ser uma estratégia para a revegetação de solos degradados sem inoculação de FMAs.The effects of increasing doses of phosphorus (0, 50, 100, 200 and 400 mg of P kg-1 of soil) and of inoculation with a mixture of arbuscular mycorrhizal fungi (AMF) upon accumulation of nitrogen and phosphorus and growth of Stylosanthes guianensis, Brachiaria decumbens, Melinis minutiflora and Stylosanthes guianensis - Melinis minutiflora mixed cultivation were evaluated in soil degraded by hydro-electrical dam construction. The experiment was conducted under greenhouse, and three cuts of the aerial part of the plants were performed with an interval of 150 days, and roots were collected only at the last cut. Shoot and root and plant accumulation of N and P in all species responded positively to P. Inoculation with AMF also increased all the above mentioned parameters. The S. guianensis presented low AMF colonization (mean of 4%), but it was very responsive to inoculation with these fungi. The effects of P application upon N accumulation on dry matter yield were also favored by inoculation with AMF. The use of M. minutiflora, that does not depend upon AMF for achieving adequate growth, can be a reasonable strategy for revegetation of degraded soils, without artificial inoculation with AMF.

O objetivo deste trabalho foi avaliar a influência do NaCl nos sistemas isoenzimáticos durante o estádio inicial de germinação do Stylosanthes guianensis (Aubl.) Sw. Sementes das variedades botânicas canenscens, microcephala, pauciflora e vulgaris foram colocadas para germinar em caixas de plástico, com papel-filtro umedecido com água (controle) e solução de NaCl (134 mmol), em estufa BOD, por 14 horas. Após este período, foi realizada a extração das enzimas glutamato desidrogenase e peroxidase. As enzimas apresentaram comportamentos diferenciados nas quatro variedades quando submetidas ao estresse salino.

Sequence-related amplified polymorphism (SRAP) is a new molecular marker technology developed based on polymerase chain reaction. The authenticity of 84 progenies of 8 hybrid combinations of Stylosanthes guianensis was identified by SRAP markers to select the true hybrids used in the present study. A total of 35 SRAP primer combinations were selected from the parents of 8 hybrid combinations. The selected polymorphism primer combinations were applied to identify the authenticity of all progenies. The male parents of the primer combinations had specific markers, whereas the female parents did not. 68 progenies exhibited male parent-specific bands, which were identified as true hybrids. The rest of the progenies were considered self-hybrids because of the absence of male parent-specific bands. The results of hybrid identification provided solid evidence for further studies of hybrids and demonstrated SRAP molecular markers as a useful technology for assessing the purity of S. guianensis hybrids. [ABSTRACT FROM AUTHOR]

We evaluated the nutritive value of 10 varieties of stylo ( Stylosanthes guianensis) in Hainan province, China, based on chemical composition and in vitro dry matter digestibility. Chemical composition of the varieties averaged 10.5% crude protein, 2.6% ether extract, 47.4% neutral detergent fiber, 39.7% acid detergent fiber and 0.59% total tannins. In vitro dry matter digestibility averaged 61.4%. The Relative Feed Value quality standard of individual varieties was grade 2 or higher, with the highest values for 'TPRC90028' and 'Reyan No. 2.' The results show that the stylo varieties have suitable nutritive values for livestock in tropical regions of China. [ABSTRACT FROM AUTHOR]

Twenty-four male 1-year old swamp buffaloes (Bubalus bubalis) were randomly allocated to 4 groups. One group grazed on guinea grass (GG) and another on guinea grass and the legume Stylosanthes guianensis (GL). The other two groups were kept in pens and fed freshly cut guinea grass and concentrate at an amount of 1.5% (GC1.5) and 2.0% (GC2.0) of body weight, respectively. The effect of the different feeding intensities on carcass characteristics and meat quality were assessed. The mean body weight at slaughter was 398 (±16) kg. Average daily gain was higher in concentrate-supplemented groups (570 and 540 g/d in GC1.5 and GC2.0, respectively) when compared to GG (316 g/d) and GL (354 g/d) (p<0.01). Likewise, the warm carcass weight was higher in GC1.5 and GC2.0 compared to GG and GL. Dressing percentage was 48.1% and 49.5% in GC1.5 and GC2.0 in comparison to 42.9% and 44.8% observed in GG and GL, respectively. Meat of Longissimus throracis from GC1.5 and GC2.0 was redder in color (p<0.01), while water holding capacity (drip and thawing loss) was improved in pasture-fed groups (p<0.05). Protein and fat content of Longissimus thoracis was higher in animals supplemented with concentrate (p<0.01), as was cholesterol content (p<0.05), whereas PUFA:SFA ratio was higher and n-6/n-3 ratio lower (p<0.01) in pasture-fed buffaloes. Results of the present study showed that the supplementation of pasture with concentrate enhances the growth and carcass characteristics of swamp buffaloes expressed in superior dressing percentage, better muscling, and redder meat with a higher content of protein and fat, whereas animals grazing only on pasture had a more favorable fatty acid profile and water holding capacity. In conclusion, the supplementation of concentrate at a rate of about 1.5% of body weight is recommended to improve the performance and carcass quality of buffaloes. [ABSTRACT FROM AUTHOR]

Stylosanthes guianensis is one of the cover crops recently introduced in direct seeding mulch-based cropping systems (DMC) in the cotton production zone in Northern Cameroon. However, its biomass production as first crop in rotations has never been assessed. The objective of this study was to evaluate the seeding year production of S. guianensis in the cotton producing zone of Cameroon, in the presence of the recommended organic and mineral fertilizer rates. Dry matter production of S. guianensis varied from 9.7 to 13.6 t ha-1 in pure stands and from 4.5 to 7.9 t ha-1 in association with corn. In the association, corn grain and straw production were 5.7 and 7.8 t ha-1, respectively. The linear effects of fertilizers on biomass production suggest that their present levels are sub optimal. However, the amounts of biomass produced should be enough for further implementation of DMC systems. Further studies are recommended to determine optimal organic and mineral fertilizer rates for S. guianensis in pure stands or in association with corn in the cotton production zone in northern Cameroon. [ABSTRACT FROM AUTHOR]

Abstract: In Vietnam soil erosion is a major environmental problem with respect to soil fertility, water quality and downstream property damages and involves 40% of total land surface. Due to a continuous and persistent decrease of soil quality under annual crops, farmers gradually convert their fields to grazing lands and their crops to fodder cultures or tree plantations. Experimental 1-m2 field plots with three replicates each were monitored for two years (2006–2007) to evaluate the impact of three different fodder treatments (Paspalum atratum, Panicum maximum and Stylosanthes guianensis) on runoff and soil detachment in a cultivated catchment of North Vietnam. These experiments were designed to monitor at local scale the protective effect of vegetation cover against splash and rain-impacted erosion. The lowest runoffs (ca. 3.0–4.4%), sediment yields (ca. 14–19gm−2 yr−1) and soil organic carbon losses (ca. 0.7gCm−2 a−1) were obtained for P. maximum that provided the best soil protection with respect to the two other treatments. These values were low as compared to cultivated crops (cassava and rainfed rice). Soil surface characteristics (mainly biological activity and crusting) did apparently not play a key role, most likely because each plant cover provided, with its own efficiency, protection against rainfall erosivity and rapid plant regrowth wiped out traces of flow detachment. The extent of soil detachment and sediment export, mainly controlled by cut and carry operations of fodder management, was reduced by increasing slope length from 1 to 5m. The choice of dense fodders such as P. maximum appears to be, in terms of improved livelihood and environment sustainability, an interesting issue for uplands farmers. [Copyright &y& Elsevier]

In most taxonomic revisions of Stylosanthes Sw., Stylosanthes gracilis Kunth has been regarded as a variety or even a synonym of S. guianensis (Aubl.) Sw. This has created considerable confusion among scientists working with the latter species which is an agriculturally important tropical forage and cover legume. This study collected taxonomically relevant evidence, for evaluating S. gracilis as a valid species. Since the type specimen is lost, a collection from the same location as the original type is proposed here as a neotype. [ABSTRACT FROM AUTHOR]

A study was conducted on the effect of different concentrations of sodium chloride (NaCl) on seedlings of Stylosanthes guianensis cv. CIAT-184 and Centrosema molle, cultivated on topsoil. Fifteen days after the treatment fresh mass, dry mass, root/shoot ratio and biomass distribution were determined, as well as the concentration of soluble phenols, cell wall-bound phenols and total phenols, in addition to chlorophyll a, b and total chlorophyll. In both cultivars the roots were the most affected organs regarding fresh mass and there was a decrease of dry mass at high concentrations of NaCl. The root/shoot ratio showed an increase at 200 mM of NaCl in S. guianensis, while no significant changes were observed in C. molle. As the concentration of NaCl increased, the concentration of soluble phenols increased noticeably in the roots of both species, as well as total phenols; while in the leaves increases in the levels of soluble phenols were observed only in S. guianensis. The concentration of chlorophyll a and total chlorophyll significantly decreased at 200 mM of NaCl in both cultivars with regards to the control. The levels of chlorophyll b decreased in C. molle at 200 mM and remained constant in S. guianensis. The chlorophyll stability value showed highly significant differences in C. molle (-8,154 and 269,1 for 100 and 200mM of NaCl), unlike S. guianensis which showed higher stability (20,47 and 31,37). The chlorophyll a/b ratio decreased in Centrosema and no differences were observed among treatments in Stylosanthes. [ABSTRACT FROM AUTHOR]

A study was conducted on the effect of different concentrations of sodium chloride (NaCl) on seedlings of Stylosanthes guianensis cv. CIAT-184 and Centrosema molle, cultivated on topsoil. Fifteen days after the treatment fresh mass, dry mass, root/shoot ratio and biomass distribution were determined, as well as the concentration of soluble phenols, cell wall-bound phenols and total phenols, in addition to chlorophyll a, b and total chlorophyll. In both cultivars the roots were the most affected organs regarding fresh mass and there was a decrease of dry mass at high concentrations of NaCl. The root/shoot ratio showed an increase at 200 mM of NaCl in S. guianensis, while no significant changes were observed in C. molle. As the concentration of NaCl increased, the concentration of soluble phenols increased noticeably in the roots of both species, as well as total phenols; while in the leaves increases in the levels of soluble phenols were observed only in S. guianensis. The concentration of chlorophyll a and total chlorophyll significantly decreased at 200 mM of NaCl in both cultivars with regards to the control. The levels of chlorophyll b decreased in C. molle at 200 mM and remained constant in S. guianensis. The chlorophyll stability value showed highly significant differences in C. molle (-8,154 and 269,1 for 100 and 200mM of NaCl), unlike S. guianensis which showed higher stability (20,47 and 31,37). The chlorophyll a/b ratio decreased in Centrosema and no differences were observed among treatments in Stylosanthes. [ABSTRACT FROM AUTHOR]

Abstract: Weaned lambs of the Phan Rang breed with an initial weight of 14.9kg and 3.5 months of age were used to study the effect of supplementing urea treated rice straw (UTRS) and molasses with different forage species as protein sources compared to a commercial concentrate with respect to digestibility, growth performance and number of gastro-intestinal parasite eggs. Eight males were used in a digestibility trial in a double 4×4 Latin square design and 32 lambs (12 males and 20 females) in a growth trial lasting 84 days. The treatments were four diets containing urea treated rice straw ad lib and molasses supplemented with concentrate (control), Stylosanthes (Stylosanthes guianensis) forage (UTR-S), Cassava (Manihot esculenta Crantz) foliage (UTR-C) or Jackfruit (Artocarpus heterophyllus) foliage (UTR-J). The live weight gain (LWG) was 73.3, 70.0, 77.7 and 70.2g/day and the feed conversion ratio 9.3, 9.0, 7.5, 10.4kgDM/kgLWG for control, UTR-S, UTR-C and UTR-J, respectively. The DM intake ranged from 33 to 44gDM/kg body weight. The DM digestibility was 0.66, 0.55, 0.60 and 0.54 and the CP digestibility 0.64, 0.65, 0.67 and 0.52 for the control, UTR-S, UTR-C and UTR-J, respectively. The nitrogen retained was 10.4, 9.8, 10.9 and 9.8g/day for the diets control, UTR-S, UTR-C and UTR-J, respectively, and was not significantly different among treatments. The UTR-C and UTR-J diets had a weak effect on the number of Nematode eggs, which was reduced or slightly increased during the experimental period. In conclusion Stylosanthes forage and Cassava and Jackfruit foliage could be used as protein sources in diets based on urea treated rice straw and replace a commercial concentrate without any effect on the live weight gain of the lambs. [Copyright &y& Elsevier]

Stylosanthes guianensis cv. CIAT-184 is a promising forage legume for poor and acid soils using for cattle production. In this research were determined the tolerance levels to salinity during in vitro seedling, thus was evaluated the organogenic response and the enzymatic activity of different explants (hypocotyls, cotyledons leaves and leaves) in a callogenic medium supplied with different NaCl levels (0-100 mM).The peroxides and catalases enzymatic activities were determined in both assays, as well as the total carbohydrates and proteins. The highest germination percentage was found between 10-20 mM/L of NaCl; a progressive diminishing of germination percentage was observed as NaCl concentration was increased. During germination assay, was determined an increase in the enzymatic activities of both catalases and peroxidases according the NaCl increasing levels, but in callogenic process the activities diminished after 50 mM of NaCl. It was possible to obtain callus in all treatments used, although the callus showed some differences in texture and colour according to the medium salt concentration. [ABSTRACT FROM AUTHOR]

The accumulation of certain metabolites and the changes in the activity of antioxidant enzymes, such as catalases and peroxidases, can be related to the plant possibilities for counteracting the negative effects of salinity on physiological and morphological processes. In this work, the levels of total proteins and carbohydrates, and the enzymatic activities of catalases and peroxidases were determined in calluses obtained from three expiants of Stylosanthes guianensis ClXI-184, cultured in MS medium supplied with 1 mg/Lof 2,4-D, 2 mg/Lde 6 BAP and different concentrations of NaCl (0, 25, 50, 75 and 100 mM). Although the activity of catalases increased until 50 mM in the three expiants and diminished after that, the highest values were detected in true leaves. On the other hand, the hypocotyls showed the highest activity of peroxidases with progressive increments until 100 mM of the evaluated salt, while the rest of expiants showed a decrease in the enzymatic activities from 75 mM. No appreciable changes were detected in total proteins, while in the carbohydrates there was considerable increase for the highest values of sodium chloride, which could be related to the accumulation of protecting osmolytes. [ABSTRACT FROM AUTHOR]

The accumulation of certain metabolites and the changes in the activity of antioxidant enzymes, such as catalases and peroxidases, can be related to the plant possibilities for counteracting the negative effects of salinity on physiological and morphological processes. In this work, the levels of total proteins and carbohydrates, and the enzymatic activities of catalases and peroxidases were determined in calluses obtained from three explants of Stylosanthes guianensis CIAT-184, cultured in MS medium supplied with 1 mg/L of 2,4-D, 2 mg/L de 6 BAP and different concentrations of NaCl (0, 25, 50, 75 and 100 mM). Although the activity of catalases increased until 50 mM in the three explants and diminished after that, the highest values were detected in true leaves. On the other hand, the hypocotyls showed the highest activity of peroxidases with progressive increments until 100 mM of the evaluated salt, while the rest of explants showed a decrease in the enzymatic activities from 75 mM. No appreciable changes were detected in total proteins, while in the carbohydrates there was considerable increase for the highest values of sodium chloride, which could be related to the accumulation of protecting osmolytes. [ABSTRACT FROM AUTHOR]

Dissolution of phosphate rocks (PR) in soils requires an adequate supply of acid (H+) and the removal of the dissolved products [calcium (Ca2 +) and dihydrogen phosphate (H2PO4-)]. Plant roots may excrete H+ or OH- in quantities that are stoichiometrically equal to excess cation or anion uptake in order to maintain internal electroneutrality. Extrusion of H+ or OH- may affect rhizosphere pH and PR dissolution. Differences in rhizosphere acidity and solubilization of three PRs were compared with triple superphosphate between a grass (Brachiaria decumbens) and a legume (Stylosanthes guianensis) forage species at two pH levels (4.9 and 5.8) in a phosphorus (P)-deficient Ultisol with low Ca content. The experiment was performed in a growth chamber with pots designed to isolate rhizosphere and non-rhizosphere soil. Assessment of P solubility with chemical extractants led to ranking the PRs investigated as either low (Monte Fresco) or high solubility (Riecito and North Carolina). Solubilization of the PRs was influenced by both forage species and mineral composition of the PR. The low solubility PR had a higher content of calcite than the high solubility PRs, which led to increased soil pH values (> 7.0) and exchangeable Ca, and relatively little change in bicarbonate-extractable soil P. Rhizosphere soil pH decreased under Stylosanthes but increased under Brachiaria. The greater ability of Stylosanthes to acidify rhizosphere soil and solubilize PR relative to Brachiaria is attributed to differences between species in net ion uptake. Stylosanthes had an excess cation uptake, defined by a large Ca uptake and its dependence on N2 fixation, which induced a significant H+ extrusion from roots to maintain cell electroneutrality. Brachiaria had an excess of anion uptake, with nitrate (NO3-) comprising 92% of total anion uptake. Nitrate and sulfate (SO42 -) reduction in Brachiaria root cells may have generated a significant amount of cytoplasmic hydroxide (OH-), which could have increased cytoplasmic pH and induced synthesis of organic acids and OH- extrusion from roots. [ABSTRACT FROM AUTHOR]

Stylosanthes guianensis is a popular pasture legume and cover crop. The legume possessed strong allelopathic potential and suppressed spontaneous growth of paddy weeds. In a bioassay, aqueous extract of S. guianensis remarkably inhibited germination and growth of barnyardgrass and monochoria. Application of 1 ton ha−1 upland parts of S. guianensis significantly reduced paddy weed biomass by 80 % and increased rice yield by 40 % when compared with the control. Gas chromatography-mass spectrometry analysis reveals the presence of several allelochemicals in S. guianensis including phenolic acids, coumarin and long-chain fatty acids. Stylosanthes guianensis may be used as a source of natural herbicide for reducing the dependency on synthetic herbicides in agricultural production. [ABSTRACT FROM AUTHOR]

Abstract: In northern Laos, rapid population growth and government policies to reduce the area under slash-and-burn systems have resulted in increased cropping intensity, which has increased weed pressure and reduced yields of upland rice. Promising alternative cropping systems include the use of weed-suppressing and multi-purpose legumes as short-term fallow crops. In this study, Stylosanthes guianensis (stylo), a promising fodder species, was seeded into upland rice at different times to identify the appropriate time of seeding. The objective is to optimize the establishment and survival of stylo during the rice growing season, and achieve high stylo biomass accumulation during fallow period, while minimizing competition with the upland rice crop during stylo establishment period. Seeding times ranged from 0 day (seeded with rice) to 83 days after rice sowing (DARS) in two experiments. In experiment 1, stylo was grown as a one-year fallow crop while in experiment 2 stylo was grown as a dry season fallow crop. The effect of stylo fallows on the subsequent rice yield, weed biomass and soil nitrogen (N) and phosphate (P) availability was evaluated in comparison with a natural weedy fallow (control). In experiment 2, the effect of burning and mulching fallow residues prior to the rice crop was also evaluated. Rice yields were reduced by an average of 55% when stylo was seeded at the same time as rice (0 DARS). When stylo was seeded later than 15 DARS, no competition effect on the accompanied rice growth was observed. Delaying stylo seeding substantially decreased total stylo and weed biomass at the end of fallow period. Following a stylo fallow, rice yields were up to 0.6t/ha higher and weed biomass was up to 60% less compared to the natural fallow (control). Furthermore, soil available N content was higher following stylo fallows. In experiment 2, the rice yields were similar when fallow residues were burned or mulched but weed biomass tended to be lower when the residues were burned. In conclusion, either pruning stylo after seeding it at the time of rice sowing or seeding stylo 15 days after rice sowing minimizes competition with upland rice while optimizing establishment and biomass accumulation of stylo during fallow period. While relay-seeding stylo appears to improve rice productivity in the short-term, the long-term sustainability of the system needs further evaluation. [Copyright &y& Elsevier]

Stylosanthes guianensis, belonging to the genus Stylosanthes, is one of the most important tropical forage legumes and is native to South and Central America and Africa. Anthracnose, caused by the fungus Colletotrichum gloeosporioides (Penz.) Sacc., is a major constraint to the extensive use of Stylosanthes as tropical forage. Forty-two accessions of S. guianensis were assessed with amplified fragment length polymorphism (AFLP) for genetic diversity and for resistance to anthracnose. In AFLP analysis, four selective primer combinations screened from 96 primer combinations were used to analyse these accessions, and a total of 225 clear bands were used for genetic similarity (GS) analysis, showing a 95.5% level of polymorphism on average. GS from 31.0% to 95.0% among the accessions was calculated with ntsys-pc software. The dendrogram was constructed with unweighted pair group method of averages (UPGMA) based on the AFLP data, and five clusters were defined at 48% GS. Two typical strains of C. gloeosporioides from Stylosanthes in China were used for anthracnose resistance screening. Most of the plant accessions showed variation in the reaction to two strains, and the correlation of resistance had a value of 0.904 (P < 0.01), suggesting common resistance to the two strains. The resistance accessions were randomly distributed in different groups of UPGMA clustering. These results demonstrate that AFLP analysis is an efficient method for evaluating the genetic diversity among S. guianensis accessions. [ABSTRACT FROM AUTHOR]

Previous studies suggest that abscisic acid (ABA) stimulates the activities of antioxidant enzymes under normal and chilling temperature and enhanced chilling resistance in Stylosanthes guianensis. The objective of this study was to test whether nitric oxide (NO) is involved in the ABA-induced activities of the antioxidant enzymes in Stylosanthes guianensis due to its nature as a second messenger in stress responses. Plants were treated with NO donors, ABA, ABA in combination with NO scavengers or the nitric oxide synthase (NOS) inhibitor and their effects on the activity of antioxidant enzymes and NO production were compared. The results showed that ABA increased the activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX). The effect of ABA on antioxidant enzyme activities was suppressed by the NOS inhibitor, Nω-nitro-L-arginine (L-NNA), and the NO scavenger, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl3-oxide (PTIO). NO content increased after 5 h of ABA treatment. The NO-scavenger, PTIO, and the NOS-inhibitor, L-NNA, inhibited the accumulation of NO in ABA-treated Stylosanthes guianensis. NO donor treatment enhanced the activities of SOD, CAT, and APX. The results suggested that NO was involved in the ABA-induced activities of SOD, CAT, and APX in Stylosanthes guianensis. ABA triggered NO production that may lead to the stimulation of antioxidant enzyme activities. [ABSTRACT FROM PUBLISHER]

Des études menées à la station de recherches zootechniques de Wakwa ont montré que la fertilisation minérale améliorait de manière significative la production fourragère des parcours. Cependant, compte tenu du coût, de la faible disponibilité des engrais, et de la situation économique des éleveurs, cette pratique est peu vulgarisable et d'autres méthodes culturales ont été envisagées pour améliorer le rendement fourrager. L'association Stylosanthes guianensis (Aubl.) S.w. cultivar FAO 46004 et Brachiaria ruziziensis Germain et Evrard a été testée dans deux parcelles. Les résultats de la culture de B. ruziziensis sur une parcelle ayant porté pendant deux ans du S. guianensis ont montré une augmentation de la production fourragère de B. ruziziensis de 20 %. Il n'a pas été observé de différence significative (p > 0,05) entre les compositions des deux fourrages. Cette pratique, sans se substituer à la fertilisation, peut donc permettre une diminution des quantités d'engrais à apporter.

Competitiveness of Brachiaria decumbens cv. Basilisk and Stylosanthes guianensis cv. Minerão was investigated either without root restriction or by separating their root systems with a fine mesh or a solid barrier in the presence or absence of mycorrhiza ( Glomus clarum). Nitrogen transfer between the legume and the grass was assessed with the 15N isotope dilution technique using a relatively stable 15N-enriched soil derived from a long-term labelling experiment. During establishment, legume development was severely restricted by competition from the grass in pots without a root barrier. However, as the system became N limited, the legume became dominant due to its access to atmospheric N2 which contributed over 80% of the legume N requirements. S. guianensis was highly mycotrophic and inoculation with mycorrhiza favoured rapid establishment even in the treatments with no root barrier. Only in the presence of root barriers, either a mesh or a complete compartment separation, was the proportion of N derived from N2 fixation positively affected by the presence of the fungus. No significant direct belowground N transfer from legume to grass was observed during the lifetime of the legume suggesting that the legume maintains a highly efficient recycling under N-limited conditions. However, after cutting the shoot at ground level, the grass assimilated significant amounts of N derived from decaying legume roots. We conclude that the main pathway of belowground N transfer from S. guianensis to associated B. decumbens occurred via decomposing roots rather than via root exudates or direct mycorrhizal hyphae transfer. [ABSTRACT FROM AUTHOR]

Plants were regenerated from leaf-derived callus cultures of five genotypes of Stylosanthes guianensis. There were substantial genotypic differences in morphogenetic potential, ranging from 95-100 % cv. `Graham' calli to less than 1 % of cv. `Oxley' calli forming shoots. A total of 1024 regenerants (SC1) were planted out, with 28.1 % surviving to set seed. Variant characters including albinism, reduced fertility, dwarfism and leaf morphology were observed. Variation in selfed progeny (SC2) of 138 SC1 plants was assessed in a replicated field trial involving 2484 SC2 individuals. Variant phenotypes were observed in 55 (39.9 %) SC2 famiIies. Many families were segregating for albinism, altered morphology or reduced fertility. Thirty families had lower yields than their parent and earlier and later flowering variants were found. Eight tetraploid families were identified. These were characterized by more erect habit, larger leaves, stems, flowers and seeds. reduced fertility and yield and a tendency to flower later. [ABSTRACT FROM AUTHOR]

Se realizó un estudio sobre el efecto de diferentes concentraciones de cloruro de sodio (NaCl) en plántulas de Stylosanthes guianensis cv. CIAT-184 y Centrosema molle, cultivadas en tierra vegetal. A los 15 días posteriores al tratamiento se determinaron la masa fresca, la masa seca, la relación raíz-brote y la distribución de la biomasa, así como la concentración de fenoles solubles, ligados a la pared y totales, además de la clorofila a, b y total. En ambos cultivares las raíces fueron los órganos más afectados con relación a la masa fresca y hubo un decrecimiento de la masa seca a elevadas concentraciones de NaCl. La relación raíz-brote mostró un aumento a 200 mM de NaCl en S. guianensis, mientras que no se observaron cambios significativos en C. molle. En la medida que la concentración de NaCl se elevó, la concentración de fenoles solubles aumentó sensiblemente en las raíces de ambas especies, así como los fenoles totales; mientras que en las hojas sólo se observaron aumentos en los niveles de fenoles solubles en S. guianensis. La concentración de clorofila a y total disminuyó significativamente a 200 mM de NaCl en ambos cultivares con relación al control. Los niveles de clorofila b disminuyeron en C. molle a 200 mM y se mantuvieron constantes en S. guianensis. El índice de estabilidad clorofílica mostró diferencias altamente significativas en C. molle (-8,154 y 269,1 para 100 y 200 mM de NaCl), a diferencia de S. guianensis que presentó una mayor estabilidad (20,47 y 31,37). La relación clorofila a/b decreció en Centrosema y no se observaron diferencias entre los tratamientos en Stylosanthes.A study was conducted on the effect of different concentrations of sodium chloride (NaCl) on seedlings of Stylosanthes guianensis cv. CIAT-184 and Centrosema molle, cultivated on topsoil. Fifteen days after the treatment fresh mass, dry mass, root/shoot ratio and biomass distribution were determined, as well as the concentration of soluble phenols, cell wall-bound phenols and total phenols, in addition to chlorophyll a, b and total chlorophyll. In both cultivars the roots were the most affected organs regarding fresh mass and there was a decrease of dry mass at high concentrations of NaCl. The root/shoot ratio showed an increase at 200 mM of NaCl in S. guianensis, while no significant changes were observed in C. molle. As the concentration of NaCl increased, the concentration of soluble phenols increased noticeably in the roots of both species, as well as total phenols; while in the leaves increases in the levels of soluble phenols were observed only in S. guianensis. The concentration of chlorophyll a and total chlorophyll significantly decreased at 200 mM of NaCl in both cultivars with regards to the control. The levels of chlorophyll b decreased in C. molle at 200 mM and remained constant in S. guianensis. The chlorophyll stability value showed highly significant differences in C. molle (-8,154 and 269,1 for 100 and 200mM of NaCl), unlike S. guianensis which showed higher stability (20,47 and 31,37). The chlorophyll a/b ratio decreased in Centrosema and no differences were observed among treatments in Stylosanthes.

La acumulación de determinados metabolitos y los cambios en la actividad de enzimas antioxidantes, como la catalasa y la peroxidasa, pueden relacionarse con las potencialidades de una planta para contrarrestar el efecto nocivo de la salinidad en los diferentes procesos fisiológicos y morfológicos. En el presente trabajo se determinaron los contenidos de proteínas y carbohidratos totales, así como la actividad de enzimas catalasas y peroxidasas, en callos obtenidos a partir de tres explantes de Stylosanthes guianensis CIAT-184, cultivados en medio MS suplementado con 1 mg/L de 2,4-D, 2 mg/L de 6 BAP y diferentes concentraciones de NaCl (0, 25, 50, 75 y 100 mM). La actividad catalasa fue mayor en las hojas verdaderas que en el resto de los explantes, aunque en los tres casos aumentó hasta 50 mM de NaCl para luego decrecer progresivamente. Por su parte, los hipocótilos mostraron la mayor actividad peroxidasa, con incrementos sostenidos hasta los 100 mM de la sal; mientras que en los otros explantes la actividad decreció a partir de 75 mM. No se detectaron cambios sustanciales en la concentración de proteínas totales; mientras que en los carbohidratos hubo un incremento considerable para las mayores concentraciones de cloruro de sodio, lo cual pudiera tener relación con la acumulación de osmolitos protectores.The accumulation of certain metabolites and the changes in the activity of antioxidant enzymes, such as catalases and peroxidases, can be related to the plant possibilities for counteracting the negative effects of salinity on physiological and morphological processes. In this work, the levels of total proteins and carbohydrates, and the enzymatic activities of catalases and peroxidases were determined in calluses obtained from three explants of Stylosanthes guianensis CIAT-184, cultured in MS medium supplied with 1 mg/L of 2,4-D, 2 mg/L de 6 BAP and different concentrations of NaCl (0, 25, 50, 75 and 100 mM). Although the activity of catalases increased until 50 mM in the three explants and diminished after that, the highest values were detected in true leaves. On the other hand, the hypocotyls showed the highest activity of peroxidases with progressive increments until 100 mM of the evaluated salt, while the rest of explants showed a decrease in the enzymatic activities from 75 mM. No appreciable changes were detected in total proteins, while in the carbohydrates there was considerable increase for the highest values of sodium chloride, which could be related to the accumulation of protecting osmolytes.

L'énergie brute (EB) de divers fourrages d'origine tropicale a été mesurée sur les fourrages suivants : Brachiaria mutica en vert en en foin, Chloris gayana en foin, Panicum maximum en vert (var. K187 B, var. T58) et en foin (var. C1), Stylosanthes guyanensis, tapis herbacé de pâturages sahéliens, pailles de mil, de riz et de sorgho, fanes d'arachide et de niébé. La teneur moyenne en EB de ces aliments est de 4182 kcal/kg MS (de 3431 à 4587) et de 4672 kcal/kg MO (de 4442 à 5018). La répartition des fourrages en cinq groupes permet d'obtenir une relation précise entre les teneurs en EB et en MAT exprimées par rapport à la matière organique (ETR = 39 kcal/kg MO, r = 0,89, n = 139). La digestibilité de l'énergie (DE) de divers fourrages a été mesurée au cours de 62 essais. Elle est comprise entre 35 et 78 p. 100 (45 et 65 p. 100 pour 74 p. 100 des fourrages) . Une relation très étroite est observée entre la DE et la DMO (ETR = 0,8, r = 0,996). La teneur en énergie digestible des fourrages varie entre 1560 et 3315 kcal/kg MS.