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.

scholarly journals Irrigation Timing as a Practice of Effective Weed Management in Established Alfalfa (Medicago sativa L.) Crop

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 550
Author(s):  
Panagiotis Kanatas ◽  
Ioannis Gazoulis ◽  
Ilias Travlos
Keyword(s):  
Medicago Sativa ◽  
Weed Management ◽  
Cultural Practices ◽  
Block Design ◽  
Chenopodium Album ◽  
Stand Density ◽  
Climatic Conditions ◽  
Amaranthus Retroflexus ◽  
Forage Yield ◽  
Medicago Sativa L

Irrigation is an agronomic practice of major importance in alfalfa (Medicago sativa L), especially in the semiarid environments of Southern Europe. Field experimentation was conducted in Western Greece (2016–2018) to evaluate the effects of irrigation timing on weed presence, alfalfa yield performance, and forage quality. In a randomized complete block design (four replications), two cultivars (“Ypati 84” and “Hyliki”) were the main plots, while three irrigation timings were the subplots (split-plot). The irrigation timings were IT-1, IT-2, and IT-3, denoting irrigation 1 week before harvest, 1 week after harvest, and 2 weeks after harvest, respectively. IT-1 reduced Solanum nigrum L. density by 54% and 79% as compared to IT-3 and IT-2, respectively. Chenopodium album L. density was the highest under IT-2. IT-3 resulted in 41% lower Amaranthus retroflexus L. density in comparison to IT-2, while the lowest values were observed under IT-1. Stand density and stems·plant−1 varied between years (p ≤ 0.05). Mass·stem−1 and alfalfa forage yield were affected by the irrigation timings (p ≤ 0.001). Total weed density and forage yield were negatively correlated in both the second (R2 = 87.013%) and the fourth (R2 = 82.691%) harvests. IT-1 and IT-3 increased forage yield, leaf per stem ratio, and crude protein as compared to IT-2. Further research is required to utilize the use of cultural practices for weed management in perennial forages under different soil and climatic conditions.

SELECTION FOR SEED SET IN NONINBRED AND PARTLY INBRED POPULATIONS OF ALFALFA

1977 ◽  
Vol 57 (3) ◽  
pp. 873-881 ◽  
Author(s):  
R. MICHAUD ◽  
T. H. BUSBICE
Keyword(s):  
Medicago Sativa ◽  
Seed Set ◽  
Exponential Model ◽  
Seed Setting ◽  
Medicago Sativa L ◽  
Selection For ◽  
Inbred Populations ◽  
The Relationship ◽  
Advanced Generation ◽  
Coefficient Of Inbreeding

Alfalfa (Medicago sativa L.) is a highly heterozygous cross-pollinating species, and most breeding efforts have been conducted on noninbred populations. The purpose of this study was to determine whether greater breeding progress could be made by selecting within partly inbred populations rather than within noninbred ones. One hundred and twenty F1 (noninbred) and 120 S1 (partly inbred) plants that were issued from crossing and selfing four alfalfa clones were evaluated for self-fertility. The most self-fertile 10% of the plants from each family were selected in each population. The selected plants within each level of inbreeding were intercrossed to produce an advanced generation in which the effectiveness of the selection was evaluated. Selection increased both self- and cross-fertility in the advanced generation. Selection was more effective at the F1 level than at the S1 level. Fertility was reduced drastically by inbreeding. The average self-fertility of the S1’s was only about 7% of the cross-fertility of their parental clones. An exponential model was proposed to describe the relationship between seed setting and the coefficient of inbreeding in the developing zygote. This model explained 95% of the variation among 11 unselected populations having differing levels of inbreeding.

WINTERHARDINESS OF ALFALFA CULTIVARS IN SOUTHERN SASKATCHEWAN

1973 ◽  
Vol 53 (4) ◽  
pp. 773-777 ◽  
Author(s):  
D. H. HEINRICHS
Keyword(s):  
North America ◽  
Medicago Sativa ◽  
Great Plains ◽  
Climatic Conditions ◽  
Northern Great Plains ◽  
Dry Land ◽  
The Third ◽  
The Usa ◽  
Medicago Sativa L

Winter injury occurring at Swift Current, Saskatchewan, was recorded in 17 tests during the period 1962–72. Cultivars developed in the Northern Great Plains Region of the USA and in Canada were generally more winter-hardy than cultivars developed in other regions of North America or in Europe. Cultivars classified as Medicago media Pers. were more winter-hardy than those classified as Medicago sativa L. Very few USA cultivars were more winter-hardy than Vernal, but most Canadian cultivars were. In nonhardy cultivars winter injury never occurred during the first winter, but it often occurred in the second winter and frequently in the third winter. There was considerably more winter injury among alfalfa cultivars on irrigated land than on dry land. Based on results from these tests, 50 cultivars and strains have been classified for relative winterhardiness under climatic conditions in southern Saskatchewan, Canada.

Determination of degradation in the rumen for dry matter, organic matter and crude protein of alfalfa (Medicago sativa L.) harvested at differentmaturity stages using the in situ nylon bag method

2016 ◽  
Author(s):  
Elif Karayilanli ◽  
Veysel Ayhan
Keyword(s):  
Organic Matter ◽  
Medicago Sativa ◽  
Crude Protein ◽  
Dry Matter ◽  
Seed Setting ◽  
Maturity Stages ◽  
Mature Period ◽  
Medicago Sativa L

The aim of this study was to determine the degradation in the rumen for the dry matter (DM), organic matter (OM) and crude protein (CP) of alfalfa (Medicago sativa L.) harvested at different maturity stages by using an in situ nylon bag method. Maturity and harvesting effects were observed in ruminally degradable DM, OM and CP. High correlations between in situ degradability and maturity were determined. Alfalfa harvested in the bud period exhibited more extensive ruminal DM, OM and CP degradation than that harvested at other maturity stages. The alfalfa hay’s DM, OM and CP degradability were lowest (62.18%, 59.52% and 76.31%, respectively) in its most mature period of seed setting; its degradability decreased with maturity (17%, 14% and 13%, respectively).

scholarly journals Studia nad kariologią i rozwojem pyłku kilku odmian Medicago saliva L. Cz. I [Studies on karyology and pollen development in several varieties of Medicago sativa L. Part I]

2015 ◽  
Vol 24 (2) ◽  
pp. 319-341
Author(s):  
K. Bijok ◽  
E. Adamkiewicz ◽  
L. Grygorczyk
Keyword(s):  
Medicago Sativa ◽  
Meiotic Division ◽  
Pollen Development ◽  
Pollen Grains ◽  
Mature Pollen ◽  
Meiotic Stage ◽  
Medicago Saliva ◽  
Medicago Sativa L

At the stage of diakinensis and metaphase of the first meiotic division, conjugating chromosomes in the form of bivalents were always observed. At the pre-meiotic stage some of .the mother pollen cells underwent degeneration (in 'Australian' var. 17% in 'Warminska' 20%, in 'Kleszczewska' 23%, in 'Grimma' 30% and in 'Miechowska' 40%). In the degenerating mother pollen cells no meiotic division were observed. In the surviving mother pollen cells, meiotic division were found to be normal. The mature pollen grains were trinucleate.

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)

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