Use of a cellulolytic enzyme digestion technique to distinguish bloat-causing from non-bloat-causing legumes and to select for speed of mesophyll cell-wall disintegration in red clover (Trifolium pratense L.)

1982 ◽  
Vol 98 (1) ◽  
pp. 99-102 ◽  
Author(s):  
F. I. Sant ◽  
D. Wilson

SUMMARYCell walls of three bloat-causing legumes, lucerne, red clover and white clover tended to be thinner and disintegrated significantly (P < 0·05) faster during cellulase digestion than those of two non-bloat-causing legumes, sainfoin (reported to contain tannins) and cicer milkvetch (reported not to contain tannins). Response to one generation of selection for speed of mesophyll cell-wall disintegration was marked in a diploid red clover (h2 = 0·66, 1·13) but slight in a tetraploid (h2 = 0·10, 0·13).

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


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


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


1992 ◽  
Vol 72 (3) ◽  
pp. 809-818 ◽  
Author(s):  
J. E. Bidlack ◽  
D. R. Buxton

Cell-wall (CW) components greatly influence digestibility of forages as they mature. There is only limited information on the timing of rates of deposition of CW components. This investigation examined differences in CW and CW component deposition in greenhouse-grown alfalfa (Medicago sativa L.), birds-foot trefoil (Lotus corniculatus L.), red clover (Trifolium pratense L.), orchardgrass (Dactylis glomerata L.), smooth bromegrass (Bromus inermis Leyss.), and switchgrass (Panicum virgatum L.). Plant material was sampled from the basal 10 cm of forage after harvesting at 3–5 cm above the soil level. Samples analyzed included sheaths from orchardgrass, sheaths and stems from bromegrass and switch-grass, and stems from all legumes. After establishment and herbage removal, samples were collected biweekly between 2 and 10 wk of regrowth. Results indicated that, except for orchardgrass, maximum rates of CW and CW component deposition usually occurred earlier in legumes compared with those of grasses. Maximum CW deposition for all species occurred within 1–3 d of maximum dry weight deposition. Among CW components in grasses and legumes, maximum deposition of hemicellulose occurred first, followed by that of cellulose (1–6 d later), and then lignin (up to 14 d after maximum hemicellulose deposition). Maximum cellulose deposition in all species occurred at the same time as maximum CW deposition.Key words: Cell wall, deposition, cellulose, hemicellulose, lignin, forage


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.


1994 ◽  
Vol 74 (4) ◽  
pp. 825-826 ◽  
Author(s):  
T. M. Choo ◽  
B. R. Christie ◽  
G. F. Bélanger ◽  
Y. A. Papadopoulos ◽  
S. Kilyanek

The red clover (Trifolium pratense L.) cultivar, AC Charlie, is a diploid of the early or double-cut type. It was developed by two cycles of mass selection for persistence and vigour. Forage yields after severe winter conditions indicate that AC Charlie is more winterhardy than Florex in Atlantic Canada. It is similar in maturity to Florex and 3–4 d later than Marino. Key words: Cultivar description, red clover, AC Charlie


1984 ◽  
Vol 64 (4) ◽  
pp. 925-934 ◽  
Author(s):  
S. R. BOWLEY ◽  
N. L. TAYLOR ◽  
P. L. CORNELIUS ◽  
C. T. DOUGHERTY

Six cycles of phenotypic recurrent selection for stem length were conducted in a 91-cm-spaced planted population of red clover (Trifolium pratense L.) as a means of increasing herbage yield. The objectives of this investigation were (1) to compare the effectiveness of selection for stem length tested in transplants at wide (91 cm) and narrow (7 cm) spacings, and in row seedings and (2) to determine the effect of selection for stem length on herbage yield. Response to selection for stem length was obtained under all plantings; however, greater gains were observed at the wide transplant spacing (3.3 cm∙cycle−1) compared to the narrow transplant spacing (0.7 cm∙cycle−1) and row seeding (0.8 cm∙cycle−1). Densely spaced transplants gave performance similar to row seedings and may be of value to forage crop breeders in situations where yield or quality assessment is desired but seed supplies are insufficient for the establishment of seeded plots, such as in the early stages of breeding programs. Selection for stem length was effective in increasing herbage yield at first harvest but was associated with reduced persistance, decreased regrowth yields, and increased partitioning of dry matter towards the shoot rather than the root during seedling development. Selection for stem length in the regrowth or in the second year, rather than in the primary (seedling) growth, might have avoided the declines in persistence and regrowth yields.Key words: Trifolium pratense L., red clover, recurrent selection, stem length, density, herbage yield


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