scholarly journals Análise comparativa de fragmentos identificáveis de forrageiras, pela técnica micro-histológica

2005 ◽  
Vol 34 (6) ◽  
pp. 1841-1850
Author(s):  
Maristela de Oliveira Bauer ◽  
José Alberto Gomide ◽  
Eldo Antônio Monteiro da Silva ◽  
Adair José Regazzi ◽  
José Franklim Chichorro
Keyword(s):  
Medicago Sativa ◽  
Brachiaria Decumbens ◽  
Melinis Minutiflora ◽  
Hyparrhenia Rufa ◽  
Medicago Sativa L

Objetivou-se, com este trabalho, verificar, pela técnica micro-histológica, diferenças entre espécies forrageiras quanto ao percentual de fragmentos identificáveis, em função do processo digestivo e da época do ano. Lâminas foliares frescas recém-expandidas, correspondentes à última e à penúltima posição no perfilho, das espécies Melinis minutiflora Pal. de Beauv (capim-gordura), Hyparrhenia rufa (Nees) Stapf. (capim-jaraguá), Brachiaria decumbens Stapf. (capim-braquiária), Imperata brasiliensis Trin. (capim-sapé), de Medicago sativa L. (alfafa) e de Schinus terebenthifolius Raddi (aroeira), amostradas nos períodos chuvoso e seco, foram digeridas in vitro e preparadas de acordo com a técnica micro-histológica. Observou-se que as espécies apresentaram diferenças marcantes na porcentagem de fragmentos identificáveis e que a digestão alterou estas porcentagens em torno de 10 %; que o período de amostragem não influenciou a porcentagem de fragmentos identificáveis para a maioria das espécies; que a presença de pigmentos e a adesão da epiderme às células dos tecidos internos da folha prejudicaram a identificação dos fragmentos; e que a digestão melhorou a visualização dos fragmentos dos capins sapé e jaraguá e da aroeira, mas prejudicou a do capim-braquiária e, principalmente, a da alfafa.

scholarly journals Características anatômicas e valor nutritivo de quatro gramíneas predominantes em pastagem natural de Viçosa, MG

2008 ◽  
Vol 37 (1) ◽  
pp. 9-17 ◽  
Author(s):  
Maristela de Oliveira Bauer ◽  
José Alberto Gomide ◽  
Eldo Antônio Monteiro da Silva ◽  
Adair José Regazzi ◽  
José Franklim Chichorro
Keyword(s):  
Brachiaria Decumbens ◽  
Melinis Minutiflora ◽  
Hyparrhenia Rufa

Avaliou-se a influência das características anatômicas e dos sítios de lignificação dos tecidos sobre o valor nutritivo de lâminas foliares de quatro gramíneas coletadas nas estações chuvosa e seca. Amostras frescas das duas últimas lâminas foliares recém-expandidas, correspondentes à última e à penúltima posição no perfilho de capim-gordura (Melinis minutiflora Pal. De Beauv), capim-braquiária (Brachiaria decumbens Staph.), capim-sapé (Imperata brasiliensis Trin.) e capim-jaraguá (Hyparrhenia rufa (Nees) Staph.) foram avaliadas quanto às características anatômicas, segundo técnicas de microscopia de luz e varredura. Nessas amostras analisou-se a proporção de tecidos e de sítios de lignificação. Também foram determinadas as concentrações de fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), lignina e celulose da parede celular, assim como a digestibilidade in vitro da matéria seca (DIVMS). Os dados foram analisados segundo delineamento inteiramente casualizado, com os tratamentos no esquema fatorial, com três repetições. Determinaram-se as correlações entre DIVMS, componentes químicos da parede celular e proporção de tecidos. Observou-se o mesmo padrão de proporção de tecidos e DIVMS no capim-gordura e no capim-braquiária, assim como nos capins sapé e jaraguá. A digestibilidade in vitro da matéria seca e os componentes da parede celular sofreram influência da estação, enquanto as características anatômicas não foram significativamente influenciadas por esse fator. Os capins gordura e braquiária caracterizaram-se por maiores proporções de bainha parenquimática do feixe e os capins sapé e jaraguá por maiores proporções de xilema e esclerênquima. Altos coeficientes negativos de correlação foram estabelecidos entre os coeficientes de digestibilidade e as proporções de xilema e esclerênquima, assim como com os teores de FDN, FDA e lignina das lâminas foliares.

Insecticidal Active Rotenoids from Plant Parts and Callus Culture of Medicago sativa L. from a Semiarid Region of India (Rajasthan)

2020 ◽  
Vol 16 (6) ◽  
pp. 937-941
Author(s):  
Sharad Vats ◽  
Preeti Mehra
Keyword(s):  
Medicago Sativa ◽  
Callus Culture ◽  
Point Of View ◽  
Semiarid Region ◽  
Disease Vectors ◽  
Vector Borne Diseases ◽  
Plant Parts ◽  
Resistant Varieties ◽  
Medicago Sativa L

Background: Vector-borne diseases are quite prevalent globally and are one of the major causes of deaths due to infectious diseases. There is an availability of synthetic insecticides, however, their excessive and indiscriminate use have resulted in the emergence of resistant varieties of insects. Thus, a search for novel biopesticide has become inevitable. Methods: Rotenoids were isolated and identified from different parts of Medicago sativa L. This group of metabolites was also identified in the callus culture, and the rotenoid content was monitored during subculturing for a period of 10 months. Enhancement of the rotenoid content was evaluated by feeding precursors in a tissue culture medium. Results: Four rotenoids (elliptone, deguelin, rotenone and Dehydrorotenone) were identified, which were confirmed using spectral and chromatographic techniques. The maximum rotenoid content was found in the seeds (0.33±0.01%), followed by roots (0.31±0.01%) and minimum in the aerial parts (0.20±0.05%). A gradual decrease in the rotenoid content was observed with the ageing of subcultured tissue maintained for 10 months. The production of rotenoids was enhanced up to 2 folds in the callus culture using amino acids, Phenylalanine and Methionine as precursors as compared to the control. The LC50 value of the rotenoids was found to be 91 ppm and 162 ppm against disease vectors of malaria and Dracunculiasis, respectively. Conclusion: The study projects M. sativa as a novel source of biopesticide against the disease vectors of malaria and Dracunculiasis. The use of precursors to enhance the rotenoid content in vitro can be an effective venture from a commercial point of view.

EFFECTS OF EARLY SUMMER AND FALL CUTTING MANAGEMENT ON DRY MATTER YIELDS, DIGESTIBILITY, CRUDE PROTEIN, AND SURVIVAL OF SARANAC AND NARRAGANSETT ALFALFAS

1972 ◽  
Vol 52 (6) ◽  
pp. 941-948 ◽  
Author(s):  
L. B. MacLEOD ◽  
H. T. KUNELIUS ◽  
F. W. CALDER
Keyword(s):  
Medicago Sativa ◽  
Crude Protein ◽  
Dry Matter ◽  
Early Summer ◽  
Good Survival ◽  
Considerable Decrease ◽  
Dry Matter Digestibility ◽  
Medicago Sativa L ◽  
Cutting Management

The effects of early summer and fall cutting managements on two alfalfa (Medicago sativa L.) cultivars were studied over a 3-year period. Removal of the first crop of Saranac and Narrangansett alfalfas at prebud stage, followed by two cuts at the early bloom stage before early September, and a late fall harvest on October 25, produced seasonal dry matter (DM) yields of 7.5–8.6 metric T/ha in the 1st year. Stand deterioration, however, was severe and by the 3rd year, practically all alfalfa had disappeared. Average percent crude protein (CP) in cut 1 was 17.7–21.9 and percent in vitro dry matter digestibility (IVD) 67.4–73.8. Removal of the first cut at bud stage with two subsequent harvests at the early bloom stage also allowed a total of three harvests before early September and resulted in seasonal DM yields of 8.6–8.8 in the 1st year. Although the survival of alfalfa was increased over the managements where cut 1 was at prebud stage, a considerable decrease of alfalfa was still observed in the 3rd year. Under this management, average CP in cut 1 was 15.8–16.3 and IVD 64.1–68.4. Harvesting the first crop at early to midbloom stage and the second crop at early bloom in early to mid-August, followed by third harvest in late October, resulted in good survival with seasonal DM yields of 6.1–10.6. Lower CP and IVD were recorded in cut 1 than in the more intensive managements. Under all managements, average CP in cuts 2 and 3 was 14.9–17.3 and 13.3–19.4, respectively. IVD was 54.5–60.7 in cut 2 and 56.0–64.4 in cut 3.

scholarly journals Correlações entre componentes anatômicos, químicos e digestibilidade in vitro da matéria seca de gramíneas forrageiras

2001 ◽  
Vol 30 (3 suppl 1) ◽  
pp. 955-963 ◽  
Author(s):  
Domingos Sávio Campos Paciullo ◽  
José Alberto Gomide ◽  
Domingos Sávio Queiroz ◽  
Eldo Antônio Monteiro da Silva
Keyword(s):  
Brachiaria Decumbens ◽  
Melinis Minutiflora

Lâminas foliares e segmentos de colmo das gramíneas forrageiras capim-braquiária (Brachiaria decumbens), capim-gordura (Melinis minutiflora) e capim-bermuda Tifton 85 (Cynodon sp) foram amostradas em dois níveis de inserção no perfilho (inferior e superior), em duas idades (momento da exposição da lígula da folha e 20 dias após) e em duas estações de crescimento (verão e outono). Amostras dos segmentos de colmo e lâminas foliares foram submetidas à determinação de sua composição química, composição anatômica e digestibilidade in vitro. Após obtenção dos dados, foram estabelecidas as correlações entre os componentes químicos e anatômicos e entre estes e a DIVMS, na lâmina, no colmo e no agrupamento dos dados das duas frações. A espessura da parede celular foi a característica anatômica a se correlacionar mais fortemente com todos os componentes químicos, independente da fração considerada. Suas correlações foram positivas com os teores de fibra em detergente neutro, fibra em detergente ácido e lignina e negativa com os de proteína bruta. A proporção de mesofilo se correlacionou positivamente com os teores de proteína bruta e negativamente com os de fibra em detergente ácido, enquanto a proporção de esclerênquima apresentou correlação positiva com os teores de fibra em detergente neutro. Os componentes químicos se correlacionaram fortemente entre si e com a DIVMS. Entre as características anatômicas, somente a espessura da parede celular mostrou correlação significativa com a DIVMS, independente da fração. O mesofilo se correlacionou positivamente e o xilema negativamente com a DIVMS, respectivamente, na lâmina e no colmo.

GENETIC VARIATION FOR FORAGE QUALITY OF ALFALFA STEMS

1987 ◽  
Vol 67 (4) ◽  
pp. 1057-1067 ◽  
Author(s):  
D. R. BUXTON ◽  
G. C. MARTEN ◽  
J. S. HORNSTEIN
Keyword(s):  
Cell Wall ◽  
Genetic Variation ◽  
Medicago Sativa ◽  
Crude Protein ◽  
Nutritive Value ◽  
Growth Traits ◽  
Forage Quality ◽  
In Vitro Digestibility ◽  
Medicago Sativa L

When normally harvested for hay, the basal portion of alfalfa (Medicago sativa L.) stems is low in forage quality. This study was conducted to determine whether genetic variation for in vitro digestible dry matter (IVDDM) and crude protein (CP) concentration of stems of perennial Medicago spp. could be identified and whether morphological and chemical traits were associated with variation in these characteristics of stems. The lower six nodes and internodes of stems and total herbage from 64 Plant Introduction (PI) accessions and five cultivars of field-grown plants were harvested twice when most plants were at the early seed-pod stage of maturity. Several morphological and growth traits were measured, and both stems and total herbage were evaluated for IVDDM and CP concentration. Covariant analysis was used to adjust in IVDDM and CP concentration of stems for differences in plant maturity. Significant variation for IVDDM and CP concentration in stems existed among the cultivars and among the accessions. Some accessions had significantly higher stem IVDDM or CP concentration than control cultivars. The M. sativa accession, PI 440496, had the fourth highest stem IVDDM and third highest stem CP, with concentrations of 374 and 79 g kg−1, respectively. The number of ridges on stems (stem shape) was significantly correlated with stem IVDDM and CP concentration with average correlation coefficients of 0.30 and 0.35, respectively. Cell-wall concentration and lignin concentration per unit cell wall of stems were both negatively correlated with stem IVDDM and CP concentration. Selection for improved nutritive value of stems may have potential for improving the nutritive value of alfalfa herbage.Key words: Alfalfa, forage quality, crude protein, in vitro digestibility, Medicago sativa L.

Field evaluation following two cycles of backcross transfer of somatic embryogenesis to commercial alfalfa germplasm

1993 ◽  
Vol 73 (1) ◽  
pp. 131-137 ◽  
Author(s):  
S. R. Bowley ◽  
G. A. Kielly ◽  
K. Anandarajah ◽  
B. D. McKersie ◽  
T. Senaratna
Keyword(s):  
Somatic Embryogenesis ◽  
Medicago Sativa ◽  
Seed Yield ◽  
Field Experiments ◽  
Field Evaluation ◽  
Growth Characteristics ◽  
Seed Technology ◽  
Artificial Seed ◽  
Medicago Sativa L

For successful application of artificial seed technology to alfalfa (Medicago sativa L.), parental plants must possess the necessary genes for somatic embryogenesis and produce progeny having high commercial value. A backcross procedure was initiated to transfer the ability to form somatic embryos from genotype A70-34, a selection from the cultivar Rangelander, to multiple-pest-resistant alfalfa germplasm. The objectives of this study were to evaluate the growth characteristics and seed yield of the F1; BC1 and BC2 generations to determine if introgression with commercial germplasm had improved the agronomic features of the embryogenic germplasm. This study consisted of two field experiments, each conducted at two locations. One experiment evaluated herbage growth characteristics and herbage production at Elora and Woodstock, Ontario, and the other evaluated seed yield at Elora and Delhi, Ontario. Significant increases in fall regrowth height, leaflet length:width ratio, and seed yield were detected over the cycles of crossing. By the BC2, fall dormancy and leaflet length:width ratio were similar to those in commercial populations. Although improvements in seed yield were detected, the BC2 was inferior in seed yield compared with commercial germplasm, and further introgression and (or) conscious selection for improved seed yield will be required. Through a population backcross procedure, it appears possible to develop commercial alfalfa germplasm capable of in vitro manipulation. Key words: Alfalfa, Medicago sativa L., somatic embryogenesis, artificial seed, backcross

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