GENETIC VARIANCE OF PROTEOLYTIC ACTIVITY IN ALFALFA HERBAGE

1987 ◽  
Vol 67 (1) ◽  
pp. 159-165
Author(s):  
S. R. BOWLEY ◽  
B. D. McKERSIE
Keyword(s):  
Medicago Sativa ◽  
Proteolytic Activity ◽  
Genetic Variance ◽  
Effective Means ◽  
Breeding Population ◽  
Narrow Sense ◽  
Nonprotein Nitrogen ◽  
Narrow Sense Heritability ◽  
Medicago Sativa L

Protein hydrolysis can be extensive during ensiling of alfalfa (Medicago sativa L.) herbage. Such hydrolysis lengthens the ensiling phase and reduces the quality of the resultant feed. The objectives of this study were: (1) to estimate the genetic variance and narrow-sense heritability (via a half-sib analysis) of proteolytic activity in an alfalfa breeding population (OAC-A83); and (2) to estimate the genetic diversity among related Medicago subspecies (M. falcata, M. varia, M. praefalcata and M. glomerata), M. sativa introductions, and two cultivars, Iroquois and OAC Minto. An in vitro procedure was used to quantify proteolytic activity, which was expressed as milligrams of trichloroacetic acid (TCA)-soluble leucine equivalents per gram fresh leaf weight, released during a 7-d incubation. Significant (P < 0.05) differences were found among the half-sib families of OAC-A83. The narrow-sense heritability of proteolytic activity was low (13.9%). The expected response to selection for low proteolytic activity, if the top 10% of the plants were recombined, was 5% of the OAC-A83 population mean. Although significant (P < 0.05) differences were obtained among the Medicago introductions, none of the introductions or subspecies tested had lower proteolytic activity than that found in the two cultivars tested (Iroquois and OAC Minto). It was concluded that, although possible, genetic improvement of proteolytic potential in alfalfa may not be easily obtained. In the short term, rapid lowering of silage pH (e.g., bacterial inoculants or acid additives) will likely remain the most effective means of controlling protein degradation in alfalfa silage.Key words: Medicago sativa L., silage, ensiling, soluble nonprotein nitrogen, heritability, alfalfa

Genetic control of somatic embryogenesis in alfalfa

Genome ◽  
1992 ◽  
Vol 35 (3) ◽  
pp. 474-477 ◽  
Author(s):  
G. A. Kielly ◽  
S. R. Bowley
Keyword(s):  
Tissue Culture ◽  
Somatic Embryogenesis ◽  
Medicago Sativa ◽  
Genetic Control ◽  
In Vitro Regeneration ◽  
Breeding Population ◽  
Medicago Sativa L

The genetic control of somatic embryogenesis in alfalfa (Medicago sativa L.) was studied using one nonembryogenic and three embryogenic genotypes: A70-34, a selection from 'Rangelander'; RA3, a selection from 'Regen-S'; and C2-4, a selection from a breeding population that had A70-34 in its pedigree. Crosses of embryogenic × embryogenic and embryogenic × nonembryogenic and S1 and BC1 testcrosses were evaluated for in vitro regeneration. Selfing reduced the expression of the trait. Somatic embryogenesis was dominant and explained by two loci. All three regenerating genotypes shared a common genetic system.Key words: alfalfa, Medicago sativa, somatic embryogenesis, tissue culture.

Estimates of Genetic Variance in ‘Cherokee’ Alfalfa ( Medicago sativa , L.) 1

Crop Science ◽  
1969 ◽  
Vol 9 (2) ◽  
pp. 228-231 ◽  
Author(s):  
John W. Dudley ◽  
T. H. Busbice ◽  
C. S. Levings
Keyword(s):  
Medicago Sativa ◽  
Genetic Variance ◽  
Medicago Sativa L

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.

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

Genetic analysis of epicuticular wax production in alfalfa

Genome ◽  
1988 ◽  
Vol 30 (6) ◽  
pp. 896-899 ◽  
Author(s):  
P. G. Jefferson ◽  
D. A. Johnson ◽  
M. D. Rumbaugh
Keyword(s):  
Medicago Sativa ◽  
Drought Resistance ◽  
Combining Ability ◽  
Genetic Material ◽  
General Combining Ability ◽  
Epicuticular Wax ◽  
Narrow Sense ◽  
Narrow Sense Heritability ◽  
Plant Nursery ◽  
Wax Production

Epicuticular wax production increases in drought-stressed plants and has been identified as a potential drought resistance selection criterion. The objective of the present study was to determine the genetic variances and narrow-sense heritability of epicuticular wax production in alfalfa (Medicago sativa L.). These parameters were determined from a 14 parent diallel cross that included all possible progeny combinations. Cross progenies, selfed progenies, and reciprocal crosses were grown in a space-plant nursery at Logan, Utah. Epicuticular wax was determined gravimetrically after washing 100 cm2 of leaves (2.5 g) in carbon tetrachloride. General combining ability was significant (P < 0.05), and estimated heritability was 35% from one harvest in 1985. Specific combining ability and reciprocal effects were not significant. A subset of six parents and their progenies were sampled for two harvests in 1986. The general combining ability by harvest interaction was significant (P < 0.01) for epicuticular wax production, indicating that the true narrow-sense heritability may be lower than 35%. The range in epicuticular wax production among harvests was as great as among progenies. A greater diversity of genetic material would be useful in a selection program for epicuticular wax production in alfalfa.Key words: Medicago sativa, heritability, drought resistance, genetic variability, diallel analysis.

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