What We Need to Know about Scientific Names: An Example with White Clover

The improvement in forage quality and quantity of summer-dry hill country pasture resulting from the introduction of clover is well recognised. However, ensuring the persistence of the commonly availablecultivars is challenging, in the face of seasonal moisture stress, intensive grazing, competition from established well-adapted pasture species, low soil fertility and low soil pH – conditions typical of the East Coast of the North Island. Here we quantify the value proposition associated with the introduction of white clover into a case study on a Gisborne sheep and beef farm, using a six-step process. A topographically explicit approach is taken, using an understanding of the underlying spatial variability, based on a combination of soil and pasture measurements, APSIM simulation modelling of pasture growth and farm system modelling of enterprise performance. We show that from a baseline of a typical low-fertility, diverse species hill country pasture, white clover introduction can increase spring and summer forage consumption by 17%, enabling inclusion of an additional 6-month bull finishing enterprise generating a 32% greater carcass weight production and leading to a 49% improvement in farm system EBIT. This represents a positive net present value of over $360,000 for the original investment in white clover establishment into existing pastures.

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THE PERFORMANCE OF S170 TALL FESCUE IN CANTERBURY

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.1974.36.1401 ◽

1974 ◽

pp. 214-215

Author(s):

B.R. Watkin

Keyword(s):

New Zealand ◽

White Clover ◽

Tall Fescue ◽

Trifolium Repens ◽

Festuca Arundinacea ◽

Sheep Grazing ◽

Selection Of

AN Aberystwyth selection of tall fescue (Festuca arundinacea Schreb.), known as S170, was sown with certified New Zealand white clover (Trifolium repens) and re' clover (T. pratense) and compared under sheep grazing with other grass/clover pastures at the Grasslands Division Regional Station at Lincoln (Watkin, 1975) .

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White clover sensitivity to UV-B radiation - biochemical relationships and interaction with drought

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.2003.65.2503 ◽

2003 ◽

pp. 273-277

Author(s):

R.W. Hofmann ◽

B.D. Campbell ◽

E.E. Swinny ◽

S.J. Bloor ◽

K.R. Markham ◽

...

Keyword(s):

New Zealand ◽

White Clover ◽

Ultraviolet B ◽

Summer Drought ◽

Stress Protection ◽

Trade Offs ◽

Population Comparisons ◽

Potential Benefits ◽

Quercetin Glycosides ◽

Balance Trade

During summertime in New Zealand, white clover experiences high levels of ultraviolet-B (UV-B) radiation. This frequently coincides with periods of summer drought. We investigated responses to UV-B and to the combination of UV-B and drought in various white clover populations, including New Zealand cultivars and ecotypes as well as overseas germplasm. The results were obtained under controlled environmental conditions in three independent trials. Overall, white clover growth was reduced by UV-B. The population comparisons indicated that low growth rate and adaptation to other forms of stress may be related to UV-B tolerance under well-watered conditions, but not during extended periods of drought. Flavonoid pigments that are involved in stress protection were strongly increased under UV-B and were further enhanced in the combination of UV-B and drought. The responses among these flavonoids were highly specific, with more pronounced UV-B-induced increases in quercetin glycosides, compared to their closely related kaempferol counterparts. UV-B toler ance of the less productive white clover populations was linked to the accumulation of quercetin compounds. In conclusion, these studies suggest (i) that slow-growing white clover ecotypes adapted to other stresses have higher capacity for biochemical acclimation to UV-B under well-watered conditions and (ii) that these biochemical attributes may also contribute to decreased UV-B sensitivity across white clover populations under drought. The findings alert plant breeders to potential benefits of selecting productive germplasm for high levels of specific flavonoids to balance trade-offs between plant productivity and stress tolerance. Keywords: Drought, flavonoids, genetic variation, HPLC, kaempferol, quercetin, str ess, Trifolium repens L., ultraviolet-B, white clover

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Implementing molecular marker technology in forage improvement

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.2003.65.2498 ◽

2003 ◽

pp. 229-238

Author(s):

M. Faville ◽

B. Barrett ◽

A. Griffiths ◽

M. Schreiber ◽

C. Mercer ◽

...

Keyword(s):

Quantitative Trait Locus ◽

Genetic Variation ◽

White Clover ◽

Simple Sequence Repeat ◽

Sequence Repeat ◽

Linkage Groups ◽

Seedling Vigour ◽

Genome Map ◽

Trait Locus ◽

Simple Sequence

Accelerated improvement of two cornerstones of New Zealand's pastoral industries, per ennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.), may be realised through the application of markerassisted selection (MAS) strategies to enhance traditional plant breeding programmes. Genome maps constructed using molecular markers represent the enabling technology for such strategies and we have assembled maps for each species using EST-SSR markers - simple sequence repeat (SSR) markers developed from expressed sequence tags (ESTs) representing genes. A comprehensive map of the white clover genome has been completed, with 464 EST-SSR and genomic SSR marker loci spanning 1125 cM in total, distributed across 16 linkage groups. These have been further classified into eight pairs of linkage groups, representing contributions from the diploid progenitors of this tetraploid species. In perennial ryegrass a genome map based exclusively on EST-SSR loci was constructed, with 130 loci currently mapped to seven linkage groups and covering a distance of 391 cM. This map continues to be expanded with the addition of ESTSSR loci, and markers are being concurrently transferred to other populations segregating for economically significant traits. We have initiated gene discovery through quantitative trait locus (QTL) analysis in both species, and the efficacy of the white clover map for this purpose was demonstrated with the initial identification of multiple QTL controlling seed yield and seedling vigour. One QTL on linkage group D2 accounts for 25.9% of the genetic variation for seed yield, and a putative QTL accounting for 12.7% of the genetic variation for seedling vigour was detected on linkage group E1. The application of MAS to forage breeding based on recurrent selection is discussed. Keywords: genome map, marker-assisted selection, perennial ryegrass, QTL, quantitative trait locus, SSR, simple sequence repeat, white clover

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USE OF CELL AND MOLECULAR GENETIC MANIPULATION TO IMPROVE PASTURE PLANTS

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.1988.49.1828 ◽

1988 ◽

pp. 67-72

Author(s):

D.W.R. White

Keyword(s):

Cell Culture ◽

Perennial Ryegrass ◽

White Clover ◽

Nutritional Quality ◽

Rust Resistance ◽

Herbicide Tolerance ◽

Pest Resistance ◽

Crown Rust ◽

Wide Range ◽

Pasture Plants

Cell culture and genetic engineering techniques can be used to develop improved pasture plants. To utilise these methods we have developed procedures for regenerating plants from tissue cultures of perennial ryegrass and white clover. In both, the plant genotype influences regeneration capacity. There was significant genetic variation among regenerated perennial ryegrass plants in a wide range of characteristics. Most of the regenerants were resIstant to crown rust and this trait was highly heritable. This rust resistance is being used to breed a new ryegrass cultivar. A system for introducing cloned genes into white clover is described. This capability is bemg used to incorporate genes with the potential to improve nutritional quality and pest resistance. Other possibilities for engineering genetic improvements in white clover, genes conferring herbicide tolerance and resistance to white clover mosaic virus, are briefly outlined. Keywords: Lolium perenne, Trifolium repens, cell culture, somaclonal variation, crown rust resistance, transformation, cloned genes, nutritional quality, proteinase inhibitors, Bt toxins, pest resistance, WCMV viral cross-protection, herbicide tolerance, Agrobacterium, Bacillus thuringenisis.

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NEW CLOVER CULTIVARS FOR WAIKATO DAIRY PASTURE: ESTABLISHMENT, PRODUCTION AND NITROGEN FIXATION DURING THE FIRST YEAR

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.1988.49.1822 ◽

1988 ◽

pp. 207-211

Author(s):

S.F. Ledgard ◽

G.J. Brier ◽

R.N. Watson

Keyword(s):

Nitrogen Fixation ◽

White Clover ◽

Dairy Cow ◽

Red Clover ◽

First Year ◽

Buried Seed

Clover cultivars grown with ryegrass were compared in an establishment year under dairy cow grazing. There was no difference in total annual productton but summer production was greater with Pawera red clover and with Kopu or Pitau white clovers. Clovers differed little in the proportion of nitrogen fixed, except during summer when values were highest for Pawera. Pawera was less prone to nematode attack than white clover cultivars but was more susceptible to clover rot. Resident clovers and high buried seed levels (e.g., 11-91 kg/ha) made introduction of new clover cultivars difficult. Sown clovers established best (50-70% of total clover plants) when drilled into soil treated with dicamba and glyphosate. Keywords: white clover, red clover, nematodes. nitrogen fixation, pasture renovation

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