scholarly journals INSECT PESTS AND THE EVOLUTION OF DEFENSIVE GLANDULAR TRICHOMES IN ALFALFA

1985 ◽  
Vol 65 (3) ◽  
pp. 589-596 ◽  
Author(s):  
ERNEST SMALL
Keyword(s):  
Medicago Sativa ◽  
Key Words ◽  
Geographical Distribution ◽  
Insect Pests ◽  
Glandular Trichomes ◽  
The Caucasus ◽  
Medicago Saliva ◽  
Medicago Sativa L ◽  
High Concentrations ◽  
Medicago Species

Glandular trichomes can defend (Medicago species from herbivores in a variety of insect orders. Wild alfalfas with high concentrations of glandular trichomes occur in a restricted portion of the geographical range of the species (Medicago saliva L. sensu lato), especially in the Caucasus, Ukraine, and adjacent areas of the USSR. These observations suggest that this adaptation was developed to defend the alfalfa against insect pests with similar geographical distribution. That M. sativa plants with pods covered with glandular hairs tend to have larger, if fewer, seeds than plants with pods lacking the hairs also suggests an adaptation against herbivores. Because the glandular trichomes occur primarily on the ovaries and pods, the pests likely feed on seeds. After considering the biology and geography of the major Soviet insect pests of cultivated alfalfa, it was concluded that the most likely insects responsible for the localized evolution of pod glandularity are species of Tychius (Coleoptera: Curculionidae).Key words: Alfalfa, Medicago sativa L., seed chalcid, Brachophagus, Tychius, glandular trichomes, pest resistance (immunity)

Shearing force of alfalfa stems: Effects of genotype and year interactions

1998 ◽  
Vol 78 (4) ◽  
pp. 719-722
Author(s):  
A. D. Iwaasa ◽  
K. A. Beauchemin ◽  
S. N. Acharya ◽  
J. G. Buchanan-Smith
Keyword(s):  
Cell Wall ◽  
Medicago Sativa ◽  
Key Words ◽  
Chemical Constituents ◽  
Stem Segment ◽  
Shearing Force ◽  
Medicago Sativa L ◽  
Genotype Clustering ◽  
Force Characteristics

Shearing force of alfalfa (Medicago sativa L.) stems was measured to evaluate genotype-by-year interactions. Based on mean shearing force for each stem segment and genotype clustering criteria, several genotypes had similarly shearing forces among years. Therefore, selecting genotypes with desirable shearing force characteristics to improve digestibility or intake potential of forages may be possible. Key words: Genotype, environment, shearing force, cell wall chemical constituents

Comparative characteristics during wilting for alfalfa conditioned by maceration or by a conventional roller-conditioner

1999 ◽  
Vol 79 (4) ◽  
pp. 509-517 ◽  
Author(s):  
Suwarno Suwarno ◽  
K. M. Wittenberg ◽  
W. P. McCaughey
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Medicago Sativa ◽  
Key Words ◽  
Dry Matter ◽  
Microbial Count ◽  
Nutrient Profile ◽  
Conditioning Treatment ◽  
Acid Detergent Fibre ◽  
Medicago Sativa L

A study was conducted to monitor nutrient and microbial count changes during wilting of alfalfa (Medicago sativa L.) in response to varying degrees of maceration at mowing. Early bloom alfalfa was mowed with either a roller-conditioner (CONV) or a macerator set to deliver four degrees of maceration during alfalfa mowing: LIGHT, LIGHT+, SEVERE, and SEVERE+. Macerated alfalfa reached 80% dry matter in 9–11 h compared with alfalfa mowed by roller-conditioner, which required 54 h. The most rapid wilting rates were associated with LIGHT+, SEVERE, and SEVERE+ maceration treatments when alfalfa was not exposed to precipitation. The wilting coefficient in the first 24 h was increased by more than 100% for the SEVERE treatment compared with alfalfa mowed using a conventional roller-conditioner in alfalfa that was not exposed to precipitation. Precipitation at 1.5 h post-mowing increased wilting time by 8.3 h to achieve 45% DM, and by 17.5 to achieve 80% DM in the SEVERE+ maceration treatment relative to alfalfa from the same conditioning treatment that was not exposed to precipitation. Precipitation at 24 h post-mowing increased wilting time to reach 80% DM by 11 h and 21 h for the LIGHT and LIGHT+ maceration treatments relative to alfalfa of the same mowing treatments not exposed to precipitation. Maceration of alfalfa resulted in a 24.2 to 26.8 h shorter wilting time relative to the conventional roller-conditioner treatment when alfalfa was exposed to precipitation at 24 h post-mowing. SEVERE and SEVERE+ maceration treatments at mowing resulted in higher (P < 0.05) neutral detergent fibre and acid detergent fibre levels post-wilting. Lactic acid bacteria populations on alfalfa tended to be higher with maceration within 1 h post-mowing (P < 0.10) and post-wilting (P < 0.08). Key words: Alfalfa, maceration, precipitation, wilting time, bacteria, nutrient profile, compressibility

The Affymetrix Medicago GeneChip® array is applicable for transcript analysis of alfalfa (Medicago sativa)

2006 ◽  
Vol 33 (8) ◽  
pp. 783 ◽  
Author(s):  
Mesfin Tesfaye ◽  
Kevin A. T. Silverstein ◽  
Bruna Bucciarelli ◽  
Deborah A. Samac ◽  
Carroll P. Vance
Keyword(s):  
Medicago Sativa ◽  
Transcript Analysis ◽  
Crop Species ◽  
Trifoliate Leaf ◽  
Model Legume ◽  
Genome Wide ◽  
Medicago Sativa L ◽  
Genome Array ◽  
Medicago Species ◽  
Medicago Genechip

The recently released Affymetrix GeneChip® Medicago Genome Array contains approximately 52 700 probe sets representing genes in both the model legume Medicago truncatula Gaertn. and the closely related crop species Medicago sativa L. (alfalfa). We evaluated the utility of the Medicago GeneChip® for monitoring genome-wide expression of M. truncatula and alfalfa seedlings grown to the first trifoliate leaf stage. We found that approximately 40–54% of the Medicago probes were detected in leaf or root samples of alfalfa or M. truncatula. Approximately 45–59% of the detected Medicago probes were called ‘present’ in all replicate GeneChips of Medicago species, indicating a considerable overlap in the number and type of Medicago probes detected between root and leaf organs. Nevertheless, gene expression differences between roots and leaf organs accounted for approximately 17% of the total variation, regardless of the Medicago species from which the samples were harvested. The result shows that the Medicago GeneChip® is applicable for transcript analysis for both alfalfa and M. truncatula.

scholarly journals Studia embriologiczne u pięciu odmian Medicago saliva L. Cz. II [Embriological studies in five varieties of Medicago sativa L. Part II.]

2015 ◽  
Vol 26 (1) ◽  
pp. 31-51
Author(s):  
K. Bijok ◽  
E. Adamkiewicz ◽  
L. Grygorczyk
Keyword(s):  
Medicago Sativa ◽  
Embryo Sac ◽  
Endosperm Development ◽  
Climatic Conditions ◽  
Low Fertility ◽  
Seed Setting ◽  
Medicago Saliva ◽  
Poor Seed ◽  
Medicago Sativa L ◽  
Pollination And Fertilization

The objective of this study was to elucidate the problem of low seedy yields of five varieties of <i>Medicago sativa</i> L. (Australijska, Grimma, Kleszczewska, Miechowska, and Warmińska) under climatic conditions of northern Poland. The study included pollination and fertilization processes, embryo sac, embryo and endosperm development. These factors in case of lack of the proper amount of pollen, and insufficient number of pollinators, may under certain environmental conditions results in poor seed setting and low fertility of the varieties studied.

Bloat in cattle fed alfalfa selected for a low initial rate of digestion

1994 ◽  
Vol 74 (3) ◽  
pp. 451-456 ◽  
Author(s):  
J. W. Hall ◽  
W. Majak ◽  
D. G. Stout ◽  
K.-J. Cheng ◽  
B. P. Goplen ◽  
...  
Keyword(s):  
Medicago Sativa ◽  
Protein Content ◽  
Key Words ◽  
Dry Matter ◽  
Initial Rate ◽  
Legume Species ◽  
The Third ◽  
Fourth Cycle ◽  
Medicago Sativa L

Investigations of legume species which do and do not cause bloat suggested that a bloat-safe alfalfa (Medicago sativa L.) might be produced by reducing its initial rate of digestion. This study compared a third cycle alfalfa synthetic selected for a low initial rate of digestion (LIRD) with a control cultivar (Beaver). The occurrence of bloat was not significantly lower when cattle were fed cycle 3 LIRD than when fed Beaver in three grazing trials or in two of three feedlot trials. The deviation of the results in the third trial could not be explained by differences in dry matter or protein content. When grown under irrigation, the 4 h dry matter disappearance (DMD) of cycle 3 LIRD was 89% to 96% of that for Beaver. This reduction was much less than has been hypothesized to prevent bloat. Without irrigation the 4 h DMD of both cultivars were reduced by 1–3% while cycle 3 LIRD continued to have a lower DMD than Beaver. LIRD may provide some protection against bloat on dry rangelands though the response may be variable in years when moisture is well supplied. Studies with a fourth cycle LIRD selection will investigate this further. Key words: Legumes, Medicago sativa L., nylon bag, digestion

Efficacy of Rumensin controlled release capsule for the control of alfalfa bloat in cattle

2001 ◽  
Vol 81 (2) ◽  
pp. 281-283 ◽  
Author(s):  
J. W. Hall ◽  
W. Majak ◽  
T. A. McAllister ◽  
J. K. Merrill
Keyword(s):  
Controlled Release ◽  
Medicago Sativa ◽  
Key Words ◽  
Stages Of Growth ◽  
Early Stages ◽  
High Incidence ◽  
Daily Frequency ◽  
Medicago Sativa L ◽  
The Difference

Rumensin controlled release capsule (CRC) was evaluated in grazing trials and in confinement with fistulated steers fed alfalfa at the vegetative to early bud stage of growth. These stages promoted a high incidence of bloat, both in animal days of bloat and in daily frequency of distension. The bolus reduced the incidence of bloat by an average of 50% in five trials, the difference being statistically significant in four of them. The cultivars AC Grazeland and Alfagraze did not differ significantly in daily bloat incidence when evaluated at early stages of growth. Key words: Cattle, bloat, legumes, Medicago sativa L.

AC Blue J alfalfa

1995 ◽  
Vol 75 (2) ◽  
pp. 469-471 ◽  
Author(s):  
S. N. Acharya ◽  
H. C. Huang ◽  
M. R. Hanna
Keyword(s):  
Medicago Sativa ◽  
Key Words ◽  
Verticillium Wilt ◽  
Bacterial Wilt ◽  
Resistant Cultivar ◽  
Research Centre ◽  
Western Canada ◽  
Medicago Saliva ◽  
Cultivar Description

AC Blue J alfalfa (Medicago saliva L.) was developed by the Agriculture and Agri-Food Canada Research Centre, Lethbridge, Alberta. This verticillium wilt and bacterial wilt resistant cultivar outyielded Beaver by about 8% in 4-yr trials and 15% in 7-yr trials in western Canada. It is well suited for hay production, dehydration, and silage in areas where verticillium wilt reduces alfalfa yield and stand life. Key words: Cultivar description, alfalfa, Medicago sativa

Companion crop, herbicide and weed effects on establishment and yields of alfalfa-bromegrass mixture

1995 ◽  
Vol 75 (1) ◽  
pp. 121-127 ◽  
Author(s):  
J. R. Moyer ◽  
D. E. Cole ◽  
D. C. Maurice ◽  
A. L. Darwent
Keyword(s):  
Medicago Sativa ◽  
Key Words ◽  
Weed Control ◽  
Detrimental Effect ◽  
Wild Oat ◽  
Combined Stress ◽  
Key Words Wheat ◽  
Medicago Sativa L ◽  
Companion Crop ◽  
Forage Yields

Alfalfa (Medicago sativa L.) and bromegrass (Bromus spp.) were seeded with and without a companion crop and with and without herbicides at Westlock and Lethbridge, Alberta, to assess the effect of weed control, companion crop and the herbicide-by-companion crop interaction on forage establishment and subsequent yields. A companion crop reduced both alfalfa and bromegrass yields for at least 2 yr after establishment on a rain fed site at Westlock and for 1 yr after establishment on an irrigated site at Lethbridge. At both sites, weed yields were higher after establishment with a companion crop than after establishment without a companion crop. Unchecked weeds in the establishment year had less effect than a companion crop on subsequent forage yields. At both locations, weed biomass in the establishment year was less than that of the companion crop. The combined stress of a companion crop and 2,4-DB application had a detrimental effect on alfalfa yield for 3 yr after establishment at Lethbridge. Key words: Wheat, barley, wild oat, redroot pigweed, dandelion

The effect of feeding hay before fresh alfalfa on the occurrence of frothy bloat in cattle

2008 ◽  
Vol 88 (1) ◽  
pp. 29-31 ◽  
Author(s):  
W. Majak ◽  
G. J. Garland ◽  
T. J. Lysyk
Keyword(s):  
Medicago Sativa ◽  
Key Words ◽  
Dactylis Glomerata ◽  
Alfalfa Hay ◽  
Medicago Sativa L ◽  
Dactylis Glomerata L ◽  
Effect Of Feeding

Alfalfa or orchardgrass hay was fed to cattle before feeding fresh alfalfa herbage at the vegetative to early bud stage of growth to observe the subsequent impact on bloat. Alfalfa hay supplements reduced the incidence of bloat by a third in one trial, but no effect was seen in a second trial. In contrast, supplements of orchardgrass hay reduced the occurrence of bloat by > 90% in 2 yr of trials. Supplemental orchardgrass hay can be effective in the control of pasture bloat. Key words: Steers, frothy bloat, Medicago sativa L., Dactylis glomerata L., hay supplements

Root and crown characteristics of alfalfas varying in fall dormancy

1994 ◽  
Vol 74 (1) ◽  
pp. 125-127 ◽  
Author(s):  
N. A. Juan ◽  
C. C. Sheaffer ◽  
D. K. Barnes
Keyword(s):  
Medicago Sativa ◽  
Key Words ◽  
Dry Weight ◽  
Nonstructural Carbohydrate ◽  
Shoot Number ◽  
Fall Dormancy ◽  
Crown Morphology ◽  
Medicago Sativa L ◽  
Crown Characteristics ◽  
Alfalfa Root

We compared root and crown characteristics of five alfalfa (Medicago sativa L.) entries which differed in fall dormancy. Alfalfas were subjected to bud or mid-bloom harvests. The most consistent entry effect occurred for root and crown dry weight and root total nonstructural carbohydrate (TNC) concentrations. Root TNC concentration was highest and root and crown weight were greatest for the nondormant and least in the most dormant entries. Entries did not consistently differ in crown bud numbers, shoot number, or shoot origin. In October, the number of elongated crown buds were greater for a non-fall dormant alfalfa Nitro than for the most fall dormant alfalfa. Key words: Alfalfa, root and crown morphology, fall dormancy, root carbohydrates

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