scholarly journals Root Nodule Enzymes of Ammonia Assimilation in Alfalfa (Medicago sativa L.)

1981 ◽  
Vol 67 (6) ◽  
pp. 1198-1203 ◽  
Author(s):  
R. Gene Groat ◽  
Carroll P. Vance
Keyword(s):  
Medicago Sativa ◽  
Root Nodule ◽  
Ammonia Assimilation ◽  
Medicago Sativa L ◽  
Enzymes Of Ammonia Assimilation

Plant determined ineffective nodules in alfalfa (Medicago sativa): structural and biochemical comparisons

1983 ◽  
Vol 61 (1) ◽  
pp. 93-106 ◽  
Author(s):  
C. P. Vance ◽  
L. E. B. Johnson
Keyword(s):  
Medicago Sativa ◽  
Phosphoenolpyruvate Carboxylase ◽  
Soluble Protein ◽  
Biochemical Parameters ◽  
Glutamate Synthase ◽  
Host Cells ◽  
Ammonia Assimilation ◽  
Infection Threads ◽  
Medicago Sativa L ◽  
Enzymes Of Ammonia Assimilation

Nodule structure, nodule enzymes of ammonia assimilation, nodule phosphoenolpyruvate carboxylase, nitrogenase-dependent acetylene reduction, and soluble protein were studied in four plant-determined ineffective genotypes and in one effective genotype of alfalfa (Medicago sativa L.) grown in a glasshouse. Ineffective nodules that formed on genotypes MnAg(In) and MnSa(In) were similar to effective nodules in early development. However, these nodules had smaller bacteroids and senesced much more rapidly than effective nodules. In contrast, nodules that formed on ineffective genotypes MnNC-3226(In) and MnNC-3811(In) were tumorlike and had few infection threads and bacteroids, and host cells were filled with starch. Nodules from plant-determined ineffective genotypes had reduced glutamine synthetase, glutamate synthase, phosphoenolpyruvate carboxylase, and nodule soluble protein when compared with effective nodules. There were differences between genotypes for all biochemical parameters assayed.

Histological and ultrastructural observations of Medicago sativa root nodule senescence after foliage removal

1980 ◽  
Vol 58 (3) ◽  
pp. 295-309 ◽  
Author(s):  
C. P. Vance ◽  
L. E. B. Johnson ◽  
A. M. Halvorsen ◽  
G. H. Heichel ◽  
D. K. Barnes
Keyword(s):  
Medicago Sativa ◽  
Root Nodule ◽  
Root Nodules ◽  
Degenerative Changes ◽  
Vascular Bundles ◽  
Nodule Senescence ◽  
Infection Threads ◽  
Medicago Sativa L ◽  
Cellular Integrity ◽  
And Control

Root nodules from control and defoliated alfalfa (Medicago sativa L.) were compared for a period of 18 days following defoliation. Bacteroid containing cells of the nodules decreased markedly for the first 10 days following defoliation, but then increased during the next 8 days. Nodule length increased continuously during the 18 days in both control and defoliated plants. Cellular integrity of vascular bundles, meristems, and infection threads was retained in nodules from treated and control plants throughout the experiment. The sequence of senescence in bacteroid containing cells was similar in nodules from both treatments. Senescence was initially observed in the cytoplasm of bacteroid containing cells. Membranes surrounding bacteroids showed degenerative changes as bacteroids senesced. Bacteroids aggregated within nodule cells. Infection threads and bacteria inside infection threads did not disintegrate. Bacteroids ultimately disappeared in senescent cells.Nodules of alfalfa appear to respond to foliar harvesting by a partial but temporary senescence from which they recover by regeneration of bacteroid containing cells.

Estimación de biomasa aérea de forrajes de invierno bajo riego a través de un dron

2019 ◽  
Vol 12 (4) ◽  
Author(s):  
Francisco Gavi Reyes ◽  
César Botello-Aguillón ◽  
Leonardo Tijerina-Chávez ◽  
Arturo Galvis-Spíndola ◽  
Rodrigo Roblero-Hidalgo
Keyword(s):  
Medicago Sativa ◽  
Avena Sativa ◽  
Medicago Sativa L

E Objetivo: Desarrollar un procedimiento para estimar biomasa con imágenes digitales captadas desde un dron y modelación 3D (ID-Dron-3D) aplicable en alfalfa (Medicago sativa L.) y avena forrajera (Avena sativa L.). Diseño/metodología/aproximación: Con una cámara digital acoplada al dron se obtuvieron imágenes antes de la cosecha de los cultivos, que fueron procesadas con software para luego estimar volumen de biomasa. En cada cultivo se midió altura de la planta y área cosechada, volumen aparente y real de biomasa, y peso de biomasa fresca y seca. Resultados: Con base en el análisis de regresión se obtuvieron modelos lineales a una p<0.05 para predecir: biomasa fresca en avena (R2=0.70) y alfalfa (R2 =0.47); y biomasa seca en avena (R2=0.78) y en alfalfa (R2=0.31) mediante ID-Dron-3D. Limitaciones del estudio/implicaciones: Considerando las R2 de los modelos obtenidos, los resultados en la avena forrajera fueron mejores, respecto a los detectados en alfalfa, lo cual se puede deber a la mayor variabilidad de la cobertura vegetal, ya que, en algunas unidades de muestreo, las plantas de alfalfa no cubrían completamente el suelo. Hallazgos/conclusiones: El rendimiento de biomasa fresca y seca de ambos cultivos se correlacionó significativamente con su respectivo volumen aparente estimado con imágenes digitales tomadas desde un dron y su procesamiento 3D (ID-Dron-3D).

ALFALFA (Medicago sativa L.) CULTIVADA EN CAMPECHE, MÉXICO Y SU INTEGRACIÓN LOCAL EN LA ALIMENTACIÓN DE CORDEROS EN CONFINAMIENTO

2018 ◽  
Vol 11 (9) ◽  
Author(s):  
CC. Castillo-Águilar
Keyword(s):  
Medicago Sativa ◽  
Pennisetum Purpureum ◽  
Medicago Sativa L

Se comparó el uso de diferentes dietas con base en heno de alfalfa cultivada (Medicago sativa L.) en Campeche y su relación con un concentrado comercial y pasto Taiwán (Pennisetum purpureum), T1=concentrado comercial, T2=T1+heno de alfalfa, T3=T1+pasto Taiwán, T4=heno de alfalfa. Se evaluó el comportamiento productivo y metabólico de corderos en sistema intensivo utilizando 20 corderos machos con encaste de Pelibuey, Dorper y Black Belly de 12.5±1 kg de peso vivo (PV). Se midió el consumo de materia seca total (CMS), la ganancia diaria de peso (GDP), la conversión alimenticia (CA), y la digestibilidad in situ de la materia seca (DISMS). También fueron evaluados el pH, nitrógeno amoniacal (NH3) y la concentración de ácidos grasos volátiles (AGV) en líquido ruminal. La mejor GDP en gramos por día, de 234 g (p?0.05) se obtuvo en el T2; en contraste, el T3 mostró la menor GDP. La dieta que incluyó la mezcla de heno de alfalfa y concentrado mejoró significativamente las condiciones de las variables pH, NH3 y AGV (p?0.05).

ALFALFA VARIETIES ZONED IN THE CENTRAL CHERNOZEM ZONE OF THE RUSSIAN FEDERATION

2020 ◽  
Author(s):  
Galina Stepanova
Keyword(s):  
Medicago Sativa ◽  
Dry Matter ◽  
Maximum Yield ◽  
The State ◽  
Average Yield ◽  
State Register ◽  
Independent Evaluation ◽  
Medicago Sativa L ◽  
Alfalfa Varieties ◽  
Central Chernozem

The article describes the main morphological and biological features of alfalfa varieties included in the State register of breeding achievements approved for use in the Central Chernozem zone of Russia. A total of 32 alfalfa varieties are included in the State register. This is 9 varieties of blue alfalfa (Medicago sativa L. subsp. Sativa) of domestic selection and 8 foreign, 11 varieties of variable alfalfa (Medicago sativa L. nothosubsp. varia (Martyn) Arcang.) domestic selection and 1 variety of foreign and 3 varieties of yellow alfalfa (Medicago sativa L. subsp. falcata (L.) Arcang.). It shows the average and maximum yield of varieties determined in the process of state variety testing, as well as independent evaluation in research institutions in the region. Varieties of blue alfalfa of domestic selection Kevsala, Elena, Satellite, Vavilovskaya Yubileynaya were the most productive. The average yield of dry matter of these varieties reaches 8.4–9.2 t/ha, the maximum — 15.3–17.7 t/ha. Alfalfa varieties Timbale and Galaxy were the most productive among foreign varieties: the average yield of dry matter was 8.1 and 8.3 t/ha, the maximum – 15.5 and 17.2 t/ha. Varieties of alfalfa variable Vitalina and Vela provided an average yield of dry matter of 7.6 and 9.0 t/ha, the maximum yield reached 15.4 and 18.1 t/ha.

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