In vitro selection for aluminium tolerance in red clover (Trifolium pratense L.)

Author(s):  
W. Pawtowski ◽  
B. Skucińska
1999 ◽  
Vol 79 (3) ◽  
pp. 351-356 ◽  
Author(s):  
B. C. Venuto ◽  
R. R. Smith ◽  
C. R. Grau

In Wisconsin, Fusarium oxysporum, Schlect., a pathogen causing vascular wilt, is the most prevalent fungal pathogen recovered from diseased red clover (Trifolium pratense L.) plants. This study was conducted to determine the mode of inheritance for red clover resistance to this pathogen and to develop resistant germplasm. Virulent isolates of this pathogen, collected from red clover plants at the Ashland Research Station, Ashland, Wisconsin, were used to screen three populations, the red clover cultivars Arlington and Marathon and the C11 germplasm, for resistant plants. Plants were inoculated with the pathogen and evaluated for reaction, using a disease-severity index (DSI) score from 1 to 5 (1 = no reaction, 5 = plant dead). Selected plants from each cycle were intercrossed to produce subsequent generations. After two and three cycles of selection, the developed populations were simultaneously evaluated for gain from selection. The gain from selection for resistance in these populations (cycle 0 minus cycle 2) ranged from 0.31 to 0.48, 0.12 to 0.75, and 0.13 to 0.83 DSI units, respectively, for Arlington, Marathon, and C11. Estimated narrow-sense heritabilities, based on cycle-1 and cycle-2 progeny, were, respectively, 0.20 and 0.37 for Arlington, 0.15 and 0.13 for Marathon, and 0.06 and 0.17 for C11. These results indicate that resistance is a quantitative trait controlled by many loci, each contributing some portion to overall resistance in the host. Key words: Red clover, Trifolium pratense L., Fusarium oxysporum, vascular wilt, resistance


Author(s):  
Gabriela Maria VICAȘ ◽  
Mircea SAVATTI

Establishing the effect of the amino acids as additional additives to the culture medium is and will be in the future one of our concerns of interest for the in vitro culture of some plants. The present study examines the effect of the glicocol added to the LS basal medium over the embryos of the Trifolium pratense L specie cultivated in vitro. There were followed: the percentage of plant regeneration of the red clover, its multiplication capacity and the formation of the root system, and also the evolution of the callus obtained on mediums with 2,4D, BA and amino acid.


Fitoterapia ◽  
2014 ◽  
Vol 94 ◽  
pp. 62-69 ◽  
Author(s):  
Paola Spagnuolo ◽  
Emanuela Rasini ◽  
Alessandra Luini ◽  
Massimiliano Legnaro ◽  
Marcello Luzzani ◽  
...  

1988 ◽  
Vol 68 (1) ◽  
pp. 103-114 ◽  
Author(s):  
S. R. BOWLEY ◽  
C. T. DOUGHERTY ◽  
N. L. TAYLOR ◽  
P. L. CORNELIUS

Yield components of five regrowth cycles, two in 1981 and three in 1982, of three red clover (Trifolium pratense L.) populations and three alfalfa (Medicago sativa L.) cultivars were compared in swards. Red clover left more stubble but produced less herbage and accumulated total yield (herbage, stubble and 10 cm depth root) at a slower rate than alfalfa during most regrowths. The percent leaf at flowering of red clover was similar to that of alfalfa. Maximum LAI declined during successive regrowths each year. Maximum crop growth rates were 30 and 34 g m−2 d−1 for red clover and alfalfa, respectively. Stem development (canopy height) followed patterns of accumulation of herbage yield. The initiation of stems was slower in red clover and stem populations were less than that of alfalfa. Selection for faster stem initiation rates, higher stem populations, and reduced partitioning of dry matter towards stem bases which would be left as stubble were suggested as ways of increasing the herbage yield of red clover.Key words: Trifolium pratense L., Medicago sativa L., yield components, growth analysis clover (red), alfalfa


1994 ◽  
Vol 143 (1) ◽  
pp. 92-95 ◽  
Author(s):  
Günter Wersuhn ◽  
Thomas Kalettka ◽  
Renate Gienapp ◽  
Gabriele Reinke ◽  
Dorothea Schulz

1999 ◽  
Vol 79 (3) ◽  
pp. 357-359 ◽  
Author(s):  
B. R. Christie ◽  
R. A. Martin

To increase the persistence of red clover (Trifolium pratense L.), phenotypic recurrent selection was conducted under field conditions. After three cycles of selection, a strain designated as CRS-16, was developed. This strain has better persistence than the check cultivars, Florex and Marino, and has a more fibrous root system. Among 4-yr-old plants, about 10% initiated new shoots from below the crown. Key words: Red clover, Trifolium pratense L. persistence, root type


1964 ◽  
Vol 12 (1) ◽  
pp. 1 ◽  
Author(s):  
GJ Hindmarsh

Development of the male and female gametophytes is traced in detail, and departures from the normal sequence of events are found at several points. Among these are pollen abortion, failure of the archesporial cell to develop in the ovule, and collapse of the embryo sac during its development. The formation of two embryo sacs per ovule is of relatively common occurrence, and this is followed by the breakdown of one or both of them. In addition, either the egg apparatus degenerates before fertilization or the nucellar plug may fail to disintegrate and so form a barrier to the passage of the pollen tube through the micropyle. The occurrence of an ovule in which an embryo sac was developing apomictically suggests that a breeding programme based on selection for somatic apospory, rather than high seed yield from sexually reproducing plants, would probably produce a strain of red clover which could maintain itself in pastures.


1976 ◽  
Vol 54 (23) ◽  
pp. 2609-2619 ◽  
Author(s):  
Lorne J. Duczek ◽  
Verna J. Higgins

Helminthosporium carbonum, a corn pathogen, and Stemphylium botryosum, an alfalfa pathogen, are both nonpathogenic on red clover (Trifolium pratense L.), while S. sarcinaeforme is a foliar pathogen on red clover. In clover leaves challenged with H. carbonum, medicarpin and maackiain were the only inhibitory compounds found in diffusates or in leaf tissue in a concentration sufficient to account for the inhibition of this fungus. Helminthosporium carbonum was inhibited by and could not degrade medicaipin and (or) maackiain in vitro. Both S. botryosum and S. sarcinaeforme were only slightly inhibited by these compounds in mycelial growth bioassays, and both fungi degraded medicarpin and (or) maackiain in vitro and some evidence was obtained that degradation occurred in vivo. In contrast with the relatively high amounts of medicarpin and maackiain that accumulated in leaves challenged with H. carbonum, relatively low amounts accumulated in leaves challenged with either S. botryosum or S. sarcinaeforme. The evidence suggests that the resistance of clover to H. carbonum can be accounted for by these phytoalexins; however, differences in relation to accumulation of, inhibition by, and breakdown of medicarpin and (or) maackiain were not enough to explain the difference in pathogenicity of S. botryosum and S. sarcinaeforme on red clover.


1989 ◽  
Vol 78 (2) ◽  
pp. 265-270 ◽  
Author(s):  
S. G. Taylor ◽  
D. G. Shilling ◽  
K. H. Quesenberry

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