Characteristics of naturalized populations of white clover (Trifolium repens) in Atlantic Canada

1989 ◽  
Vol 67 (8) ◽  
pp. 2297-2301 ◽  
Author(s):  
Joanna Fraser

Some characteristics of seven populations of naturalized white clover (Trifolium repens L.) from native pastures in Nova Scotia, Prince Edward Island, and New Brunswick were investigated. Nine vegetative characters were measured on 16- to 18-week-old plants, and within and between population differences determined for cyanogenesis. Variation was observed between and within populations for all measured characteristics. Leaf marks were predominately the central V-shaped chevron; one population had plants without the chevron. Relative leaf size (length × width) ranged from 145 to 784 mm2. Hydrogen cyanide concentrations in leaf laminae were lower in cyanogenic (AcLi) and glucosidic (Acli) genotypes than enzymatic (acLi) genotypes. HCN concentrations in genotypes varied between and within populations. A population from Charlottetown, Prince Edward Island, had several desirable agronomic features, e.g., larger leaves, longer petioles, and thicker stolons than other populations, and could be used in a breeding programme for improved winter-hardy white clover varieties suited for rotational grazing and silage in Atlantic Canada.

1988 ◽  
Vol 110 (1) ◽  
pp. 145-154 ◽  
Author(s):  
R. Cook ◽  
D. R. Evans

SummaryThe expression of symptoms of stem nematode reproduction on a total of 53 white clovers (26 cultivars, 14 genepools and 13 introductions from plant collections) was studied in a series of field and glasshouse experiments. Seedlings or stolon-tip cuttings were inoculated with nematodes and the clovers classified by the proportion of plants which developed symptoms. Significant differences were found between varieties although in each test the majority was intermediate between more resistant and susceptible extremes. There was significant positive correlation between tests, in spite of different inoculation methods and different average levels of susceptibility. Very large-leaved cv. Aran was more resistant than most other clovers tested, and small-leaved cv. S. 184 was more susceptible. There was no general correlation of leaf size with reaction to stemnematode. Small-leaved cv. Pronitro was also resistant while several large-leaved cultivars were susceptible. In observations of plants exposed to nematodes over a long period, either by sequential inoculations or through perpetuating latent infections, apparently resistant plants eventually succumbed and supported nematode reproduction. It has not been determined whether this was because selection for virulence in the nematodes had occurred.


1997 ◽  
Vol 37 (2) ◽  
pp. 159 ◽  
Author(s):  
S. G. Clark ◽  
M. J. McFadden

Summary. The herbage yield, stolon characteristics and soil seed reserves of a diverse range of white clover (Trifolium repens L.) cultivars were studied at Hamilton in south-western Victoria. The cultivars were sown with perennial grass (Phalaris aquatica L.) and the pasture was rotationally grazed by sheep. The aim of the study was to identify white clover types which would persist under sheep grazing. The widely used cultivar, Haifa, fails to persist in this environment. Cultivars were divided into 3 groups depending on leaf size (range 2.5–13.0 cm2). Large-leaved cultivars were the most productive in the first year of the experiment but by year 3 some of the intermediate leaf-size cultivars were the most productive. Haifa (large leaved) was particularly unproductive in the third year compared with other large and intermediate leaf-size cultivars. Stolon characteristics were measured in early spring 1987, mid summer 1988 and early autumn 1988. Total stolon yield on each occasion was 0.46–0.99, 0.65–1.68 and 0.05–0.25 t DM/ha respectively. Intermediate leaf- size cultivars tended to have the highest stolon yields on each occasion. Stolon yield declined at the same rate (mean 87%; range 81–92%) in all cultivars between the second and third sampling date indicating that there is no variation in the cultivars’ ability to survive the summer drought period. Although seed reserves for most cultivars were high at the end of the experiment (range 11–130 kg/ha) no seedling recruitment was observed and seed is thought to play no role in sward survival in this environment. Plant breeders developing white clover cultivars for this environment should concentrate on maximising stolon yield at the beginning and end of the summer drought period (January–mid March). Intermediate leaf-size genotypes are likely to provide the best combination of stolon and herbage yield. Grazing management should also aim to maximise stolon yield at these critical times. The use of large-leaved, non-stoloniferous cultivars should be discouraged by advisers as they are not suited to this marginal environment under sheep grazing.


1996 ◽  
Vol 6 ◽  
pp. 7-14
Author(s):  
R.D.J. Mather ◽  
D.T. Melhuish ◽  
M. Herlihy

White clover (Trifolium repens L.) is the dominant legume of temperate pastures, having been improved by breeding since the 1930s. The 1994 OECD Register lists 93 cultivars, with a further 25-30 cultivars also known to commerce. Therefore, in excess of 100 cultivars are available to fulfil a world annual market of 8500-10,500 MT. Globally, New Zealand is the major white clover production region, providing 50- 55% of the seed. Other key production regions are Denmark, USA and South America. Consumption of white clover has been relatively static for some time, ranging from 8000-10,000 MT per annum. Between 55-60% of the seed is used in the northern hemisphere (approx. 40% by Western Europe - UK, France, Germany). USA, South America and New Zealand all consume similar tonnages annually (approx. 1000-2000 MT each) with smaller tonnages used in Australia. One cultivar, Grasslands Huia, has dominated the world white clover seed market for many years and it still remains the world's major cultivar by volume. However, in the last 10 years its position has come under increasing pressure from New Zealand and international proprietary cultivars. Eventually proprietary cultivars with improved agronomic performance will supersede the consumption of commodity/public white clovers in those countries where national listing is required to obtain release and recommended listing is need to ensure successful marketing. Despite this, Grasslands Huia will continue for many years to play a major role in supplying markets where national listing is not a prerequisite to release and price is a major factor in purchase decisions. Keywords: commodity cultivar, global market, Grasslands Huia, leaf size, market share, production trends, proprietary cultivar, seed industry, Trifolium repens L., white clover


1998 ◽  
Vol 35 (3) ◽  
pp. 419-427 ◽  
Author(s):  
D.P. Malinowski ◽  
D.P. Belesky ◽  
J. Fedders

1996 ◽  
Vol 6 ◽  
pp. 141-143
Author(s):  
D.R. Woodfield ◽  
J.R. Caradus ◽  
G.R. Cousins ◽  
T. Dunn

Increased taproot diameter is an important component in maintaining white clover (Trifolium repens L.) growth, nitrogen fixation and persistence during short-term moisture stress. Previous reports indicated selection for large taproot diameter would result in commensurate increases in leaf size and poorer growth habit. The current research investigates the response to selection for taproot diameter and the association between taproot diameter and leaf size in large-leaved clovers suited to dairy grazing systems. Taproot diameter increased by 2.4% per cycle while leaf size and growth habit were not significantly altered. Furthermore, while taproot diameter did not increase between cycle 2 and 3, the root index which measures the ratio of taproot diameter to leaf size increased linearly across all three cycles. These results suggest it is possible to select white clovers for dairying which have larger taproot diameter while maintaining a suitable growth habit. Keywords: dairying, drought, genetic improvement, root morphology, Trifolium repens L., white clover,


2007 ◽  
Vol 47 (1) ◽  
pp. 110 ◽  
Author(s):  
J. F. Ayres ◽  
J. R. Caradus ◽  
R. D. Murison ◽  
L. A. Lane ◽  
D. R. Woodfield

A breeding project has developed a new synthetic white clover (Trifolium repens L.) cultivar, Grasslands Trophy, that possesses tolerance of summer moisture stress in dryland pasture environments in the 850–1250 mm average annual rainfall temperate perennial pasture zone in eastern Australia. The breeding strategy used to develop Grasslands Trophy was an in situ breeding cycle for: (i) identifying and selecting superior genotypes, (ii) crossing elite germplasm and (iii) progeny testing derived breeding lines for the expression of key agronomic and grazing value traits. The primary selection criteria were early vigour, herbage yield, persistence and seed yield potential. Parental selection was also applied for seed yield, uniformity of leaf size, uniform flowering pattern and freedom from disease and virus symptoms. Grasslands Trophy is medium–large in leaf size with stable leaf size, combines intermediate stolon density with intermediate stolon thickness, and expresses high stolon survival and strong autumn regrowth following summer moisture stress. Grasslands Trophy has mid-season flowering maturity, intensive flowering prolificacy and high seed yield capability. Agronomic results from trials in northern New South Wales and New Zealand indicate that Grasslands Trophy has broad adaptation, expresses high summer and winter growth activity, and is reliably persistent for at least 4 years.


Author(s):  
B.M. Cooper ◽  
P.T.P. Clifford ◽  
W.M. Williams

Grasslands Challenge (Trifolium repens L.) white clover was developed to incorporate potential growth benefits, and disease resistance, in two double cross hybrids (Mediterranean × New Zealand) identified in evaluations at Kaikohe. Thirty-three elite selections of hybrids and New Zealand material were polycrossed for seed production. Progeny testing resulted in 27 parental lines with improved resistance to leaf disease and stem nematode (Ditylenchus dipsaci) relative to Grasslands Pitau. Testing of the maternal lines for seedling characteristics resulted in the deletion of one parent. A bulk line was evaluated in mini plots, and a hill country grazing trial, and showed improved growth to the control. In a grazing trial conducted in the Manawatu, Challenge showed outstanding winter production. The selection has a high stolon density in combination with a medium to large leaf size. This will allow Challenge to recover quicker from drought stress and grazing pressure. The plant type and early results indicate Challenge will be best suited to a rotational grazing management, particularly in regions where significant cool-season growth occurs. Plant Variety Rights were granted in 1997, and commercial seed should be available in 1998. Keywords: Grasslands Challenge, leaf disease, Mediterranean hybrids, stem nematode, Trifolium repens


Plant Science ◽  
2003 ◽  
Vol 165 (3) ◽  
pp. 531-539 ◽  
Author(s):  
Elizabeth S. Jones ◽  
Leonie J. Hughes ◽  
Michelle C. Drayton ◽  
Michael T. Abberton ◽  
Terry P.T. Michaelson-Yeates ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document