Varietal reaction and genetic resistance of subterranean clover (Trifolium subterraneum L.) to subterranean clover stunt virus infection

1960 ◽  
Vol 11 (5) ◽  
pp. 723 ◽  
Author(s):  
NW Grylls ◽  
JW Peak
Keyword(s):  
New Zealand ◽  
Virus Infection ◽  
Iberian Peninsula ◽  
Genetic Resistance ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Third Generation ◽  
Subterranean Clover Stunt Virus ◽  
Mediterranean Regions ◽  
The Mediterranean

Resistance to subterranean clover stunt virus was explored in 390 strains and named varieties of subterranean clover from the Mediterranean regions, England, France, the Iberian peninsula, New Zealand, and Australia. High levels of genetic resistance were shown in the Australian varieties Tallarook, Hill's Small, and Bass B. Resistance of a selected group of F2's was found to be midway between that of the parents. In selected groups of F4 generation hybrids, and in selected second and third generation backcrosses, resistance equal to that of Tallarook was shown. The apparent recovery of some plants during tests in the glass-house was shown to be a form of temporary tolerance to the virus.

An analysis of the frequency and timing of false break events in the Mediterranean region of Western Australia

2001 ◽  
Vol 52 (3) ◽  
pp. 367 ◽  
Author(s):  
R. Chapman ◽  
S. Asseng
Keyword(s):  
Western Australia ◽  
Mediterranean Region ◽  
Meteorological Data ◽  
Seasonal Pattern ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dormancy Release ◽  
The Poor ◽  
Time Periods ◽  
The Mediterranean

Historical meteorological data were used to estimate the frequency and timing of false break events at 10 locations in the annual pasture and wheat producing area in the Mediterranean climatic region of Western Australia. The seasonal pattern of false breaks identified by this analysis was compared with the dynamics of dormancy release in a field population of subterranean clover (Trifolium subterraneum L.) to determine the influence that these events may have on the legume content of annual pasture communities in this region. False break events were estimated to occur on approximately 2 of every 3 years (611–72% of years) with no significant differences across the area investigated. Changes in the risk of false break events were examined over discrete time periods. The period of greatest risk was predicted to occur during early autumn (early March to mid April). Seed softening is virtually complete in subterranean clover at this point. The seed bank strategy of this species is, therefore, not well adapted to withstand the effects of false breaks. This might largely explain the poor persistence of subterranean clover in the annual pasture communities in the Mediterranean region of Western Australia. The legume content of these pastures might be improved by selecting species with late dormancy release strategies that will give better protection from false breaks.

The effects of frosts on seed production in subterranean clover (Trifolium subterraneum)

1971 ◽  
Vol 11 (49) ◽  
pp. 202 ◽  
Author(s):  
WR Scott
Keyword(s):  
New Zealand ◽  
Seed Production ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
The Other ◽  
The Past ◽  
Seed Yields

Six cultivars of subterranean clover, Geraldton, Yarloop, Woogenellup, Clare, Mount Barker, and Tallarook, were grown as ungrazed swards at 1,700 feet a.s.1. in the Mackenzie Country of South Canterbury, New Zealand. In this very frosty environment seed yields tended to increase with increasing lateness of flowering although Clare and perhaps Tallarook appeared to be more frost susceptible than the other cultivars. It is suggested that the deleterious effects of frosts in reducing the seed yields of subterranean clover may have been overemphasized in the past and that the trend for seed yields to increase with increasing lateness of flowering can be partially explained by differences in runner production.

Genetic improvement of subterranean clover (Trifolium subterraneum L.). 2. Breeding for disease and pest resistance

2014 ◽  
Vol 65 (11) ◽  
pp. 1207 ◽  
Author(s):  
P. G. H. Nichols ◽  
R. A. C. Jones ◽  
T. J. Ridsdill-Smith ◽  
M. J. Barbetti
Keyword(s):  
Plant Breeding ◽  
Mosaic Virus ◽  
Pest Resistance ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Yellow Mosaic Virus ◽  
Genotypic Differences ◽  
Pythium Irregulare ◽  
Halotydeus Destructor ◽  
Subterranean Clover Stunt Virus

Subterranean clover (Trifolium subterraneum L.) is the most widely sown pasture legume in southern Australia and resistance to important diseases and pests has been a major plant-breeding objective. Kabatiella caulivora, the cause of clover scorch, is the most important foliar fungal pathogen, and several cultivars have been developed with resistance to both known races. Screening of advanced breeding lines has been conducted to prevent release of cultivars with high susceptibility to other important fungal foliar disease pathogens, including rust (Uromyces trifolii-repentis), powdery mildew (Oidium sp.), cercospora (Cercospora zebrina) and common leaf spot (Pseudopeziza trifolii). Several oomycete and fungal species cause root rots of subterranean clover, including Phytophthora clandestina, Pythium irregulare, Aphanomyces trifolii, Fusarium avenaceum and Rhizoctonia solani. Most breeding efforts have been devoted to resistance to P. clandestina, but the existence of different races has confounded selection. The most economically important virus diseases in subterranean clover pastures are Subterranean clover mottle virus and Bean yellow mosaic virus, while Subterranean clover stunt virus, Subterranean clover red leaf virus (local synonym for Soybean dwarf virus), Cucumber mosaic virus, Alfalfa mosaic virus, Clover yellow vein virus, Beet western yellows virus and Bean leaf roll virus also cause losses. Genotypic differences for resistance have been found to several of these fungal, oomycete and viral pathogens, highlighting the potential to develop cultivars with improved resistance. The most important pests of subterranean clover are redlegged earth mite (RLEM) (Halotydeus destructor), blue oat mite (Penthaleus major), blue-green aphid (Acyrthosiphon kondoi) and lucerne flea (Sminthurus viridis). New cultivars have been bred with increased RLEM cotyledon resistance, but limited selection has been conducted for resistance to other pests. Screening for disease and pest resistance has largely ceased, but recent molecular biology advances in subterranean clover provide a new platform for development of future cultivars with multiple resistances to important diseases and pests. However, this can only be realised if skills in pasture plant pathology, entomology, pre-breeding and plant breeding are maintained and adequately resourced. In particular, supporting phenotypic disease and pest resistance studies and understanding their significance is critical to enable molecular technology investments achieve practical outcomes and deliver subterranean clover cultivars with sufficient pathogen and pest resistance to ensure productive pastures across southern Australia.

scholarly journals Suitability of new subterranean clovers in the Canterbury region

2000 ◽  
pp. 161-165 ◽  
Author(s):  
K. Widdup ◽  
C. Pennell
Keyword(s):  
New Zealand ◽  
Seed Set ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Late Winter ◽  
Summer Drought ◽  
Seedling Regeneration ◽  
Breeding Lines ◽  
Herbage Yield ◽  
Late Maturity

The annual legume, subterranean clover, is adapted to permanent pastures in the summer drought-prone areas of eastern New Zealand. Dry summers over the last decade in Canterbury have renewed the interest from farmers in the use of sub clover. As the previously used cultivars Mt Barker and Tallarook are no longer available, a trial was established at AgResearch Templeton to evaluate a new series of cultivars and breeding lines from Australia together with recent New Zealand selections. The lines were sown in rows in May 1993 and assessed for seed set, autumn seedling regeneration and spring growth under sheep grazing for 4 years. The new Australian cultivars had improved seed set and consistently better seedling regeneration and herbage yield compared with older cultivars. The late-flowering, small-leaved and densely branched types were best adapted to the Canterbury environment. The late-maturity cultivars Denmark and Leura, selected from Sardinian germplasm, re-established 50% more seedlings and produced 25% greater late winter/ spring growth than Mt Barker and Tallarook in the third year. The New Zealand selection Ak 948 had similar performance to Denmark and Leura but the remaining selections were mediocre by the fourth year. The Sardinian ecotype breeding material appeared well-adapted to Canterbury conditions and future cultivars based on this material may be most suitable. Further trials are required in harsher sites to confirm these cultivar recommendations. Keywords: Australian cultivars, dry regions, herbage yield, seedling regeneration, subterranean clover, Trifolium subterraneum

Evolution in sown populations of subterranean clover (Trifolium subterraneum L. ) in South Australia

1992 ◽  
Vol 43 (7) ◽  
pp. 1583 ◽  
Author(s):  
PS Cocks
Keyword(s):  
Natural Selection ◽  
Flowering Time ◽  
Mediterranean Basin ◽  
South Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Sole Source ◽  
Selection For ◽  
The Mediterranean ◽  
The Mediterranean Basin

The seed banks of three pastures at Kingscote, Parndana and Waterloo, S.A., were sampled to determine the frequency of divergent genotypes in subterranean clover, and the direction of natural selection. The seeds were grown in nursery rows at Adelaide, and the resulting plants classified into one of the commercial cultivars, or as divergent genotypes. The divergent genotypes from one locality, Kingscote, were described in terms of 17 variables, and compared with strains collected from southern Australia and the Mediterranean basin. At each locality there was more genetic diversity than had been sown, both in terms of additional cultivars and the presence of divergent genotypes. The percentage of divergent genotypes appeared to be proportional to the age of the pasture, and was greatest at Kingscote, where it reached 67% of the population. The Kingscote genotypes were genetically related to Mt Barker and Dwalganup, only five out of 283 genotypes having leaf markings that differed from both cultivars. The 17 variables fell between the values recorded for Mt Barker and Dwalganup, and there was evidence of directional selection. For example, formononetin content was less, and genistein more than would be expected in the absence of natural selection. Mean flowering time was about equal to that of Seaton Park, and closer to Mt Barker than to Dwalganup. Flowering time was related to elevation above the lowest point in the paddock, the latest genotypes tending to inhabit sites at the foots of slopes, and the earliest genotypes sites on the tops. Seed and burr weight were slightly larger than expected. Hybridization was the most important, but not the sole source of genetic divergence at Kingscote, whereas contamination was the main source at Waterloo. It is likely that only a minority of the divergent genotypes was generated by mutation. The Australian subterranean clovers were as diverse as those from the Mediterranean. Those from Kingscote were also diverse, but, on the whole, had longer peduncles, shorter internodes and were taller than strains from other parts of Australia and from the Mediterranean basin.

AGWEST Sothis: Trifolium dasyurum (eastern star clover)

2007 ◽  
Vol 47 (12) ◽  
pp. 1512 ◽  
Author(s):  
A. Loi ◽  
B. J. Nutt ◽  
C. K. Revell ◽  
R. Snowball
Keyword(s):  
Dry Matter ◽  
Eastern Mediterranean ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Late Winter ◽  
Long Period ◽  
Pasture Legumes ◽  
Mediterranean Regions ◽  
World Agriculture ◽  
Annual Medics

Trifolium dasyurum C. Presl. (eastern star clover) is a species native to the eastern Mediterranean regions. AGWEST Sothis is the first cultivar of eastern star clover released to world agriculture. It has high levels of dry matter and seed production and seed can be harvested with modified grain harvesters. AGWEST Sothis is suitable for use on acid and alkaline fine-textured soils in low to medium rainfall areas (325–450 mm) in southern Australia. AGWEST Sothis is an early to mid-maturing variety, flowering ~100 days after emergence in Perth, Australia. Individual seeds weigh ~6 mg. In regenerating stands, AGWEST Sothis germinates very late in the season compared with traditional pasture legumes such as subterranean clover (Trifolium subterraneum L.) and annual medics (Medicago spp.) and weeds. The delay in germination allows the use of non-selective herbicides or intensive grazing after the break of season for a long period 3–6 weeks to obtain >90% control of troublesome crop weeds. In spite of its late germination, AGWEST Sothis grows rapidly in late winter/spring and can become a productive legume-dominant pasture for grazing or forage conservation.

scholarly journals Subterranean clover (Trifolium subterraneum): its history and current and future research in New Zealand

2003 ◽  
Vol 11 ◽  
pp. 61-72
Author(s):  
M.L. Smetham
Keyword(s):  
New Zealand ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Future Research ◽  
Pasture Production ◽  
Research Directions ◽  
Hill Country ◽  
Moisture Deficit ◽  
History Of ◽  
Future Research Directions

This review covers the history of subterranean clover (Trifolium subterraneum) and its present occurrence in New Zealand; a review of research and conclusions to be drawn from this; and examines past and future research directions. Subterranean clover has been important in terms of area of use in New Zealand since the late 1930's. Today it makes a significant contribution to pasture production on steep, north-facing North Island hill country where effective rainfall is low, and in other areas where soil moisture drops below wilting point for between 2 weeks and 5 months of the year. Research has identified the superiority of cultivars possessing a compact, ground-hugging habit of growth, and flowering late, in late October - early November, for use in North Island hill country. In drier areas, more research is needed to identify superior cultivars, although there is evidence that lines in the mid-season or early mid-season flowering groups may be appropriate. A major problem for the use of subterranean clovers in New Zealand is the slow breakdown of hardseededness. About 7 M ha of land in New Zealand is mapped as being subject to slight to severe moisture deficit (an area which could with advantage support subterranean clover), but further research is needed to identify appropriate cultivars for 4.8 M ha or more of this area. Key words: history, New Zealand, research, Trifolium subterraneum

Genetic improvement of subterranean clover (Trifolium subterraneum L.). 1. Germplasm, traits and future prospects

2013 ◽  
Vol 64 (4) ◽  
pp. 312 ◽  
Author(s):  
P. G. H. Nichols ◽  
K. J. Foster ◽  
E. Piano ◽  
L. Pecetti ◽  
P. Kaur ◽  
...  
Keyword(s):  
Seed Production ◽  
Western Europe ◽  
Nutritive Value ◽  
Atlantic Coast ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Farming Systems ◽  
Local Market ◽  
Selection For ◽  
The Mediterranean

Subterranean clover (Trifolium subterraneum L.) is the most widely sown annual pasture legume species in southern Australia, valued in the livestock and grains industries as a source of high-quality forage and for its ability to fix atmospheric nitrogen. From its initial accidental introduction into Australia in the 19th Century and subsequent commercialisation in the early 1900s, 45 cultivars have been registered in Australia. These consist of 32 cultivars of ssp. subterraneum, eight of ssp. yanninicum, and five of ssp. brachycalycinum and range in flowering time from 77 to 163 days from sowing, enabling the species to be grown in a diversity of rainfall environments, soil types, and farming systems. Eleven of these cultivars are introductions from the Mediterranean region, 15 are naturalised strains collected in Australia, 18 are the products of crossbreeding, and one is derived from mutagenesis. Cultivars developed in Italy have been commercialised for the local market, whereas other cultivars developed in Spain, Portugal, and France have not had commercial seed production. Important traits exploited include: (i) selection for low levels of the oestrogenic isoflavone formononetin, which causes reduced ewe fertility; (ii) increased levels of dormancy imposed by seed-coat impermeability (hard seeds) for cultivars aimed at crop rotations or unreliable rainfall environments; (iii) strong burr-burial ability to maximise seed production; (iv) resistance to important disease pathogens for cultivars aimed at medium- and high-rainfall environments, particularly to Kabatiella caulivora and root rot pathogens; (v) resistance to pests, particularly redlegged earth mites; and (vi) selection for unique leaf markings and other morphological traits (where possible) to aid cultivar identification. Cultivar development has been aided by a large genetic resource of ~10 000 accessions, assembled from its centre of origin in the Mediterranean Basin, West Asia, and the Atlantic coast of Western Europe, in addition to naturalised strains collected in Australia. The development of a core collection of 97 accessions, representing almost 80% of the genetic diversity of the species, and a genetic map, provides a platform for development of future cultivars with new traits to benefit the livestock and grains industries. New traits being examined include increased phosphorous-use efficiency and reduced methane emissions from grazing ruminant livestock. Economic analyses indicate that future trait development should focus on traits contributing to increased persistence and autumn–winter productivity, while other potential traits include increased nutritive value (particularly of senesced material), increased N2 fixation ability, and tolerance to cheap herbicides. Beneficial compounds for animal and human health may also be present within the species for exploitation.

PERFORMANCE OF SUBTERRANEAN AND WHITE CLOVER VARIETIES IN DRY HILL COUNTRY

1986 ◽  
pp. 53-62 ◽  
Author(s):  
D.F. Chapman ◽  
G.W. Sheath ◽  
M.J. Macfarlane ◽  
P.J. Rumball ◽  
B.M.Cooper G. Crouchley ◽  
...  
Keyword(s):  
New Zealand ◽  
White Clover ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Moisture Stress ◽  
Hill Country ◽  
Cold Environments ◽  
Dry Conditions ◽  
Country Selection ◽  
Firm Selection

Nine subterranean clover cultivars and 10 white clover varieties, differing in characters such as morphology and flowering date (sub clover), or growth habit and seeding ability (white clover), where evaluated for persistence and production at 8 summer-dry hill country sites. Results for the first 3-4 years suggest the sub clovers on the New Zealand Acceptable Herbage Cultivars List (Mt Barker, Tallarook, Woogenellup, Glare) should be revised. Regeneration of Woogenellup and Glare was consistently poor, while Tallarook performed well at most sites. The current unavailability of Tallarook seed means Mt Barker is the only effechve option for grasslands in most of New Zealand. Cultivars of the sub clover subspecies yanmnicum (Larisa, Trikkala) showed promise for winter~wet, summer dry environments, as did Nangeela in winter-cold environments. A late-flowering, prostrate, low oestrogenic sub clover similar to Tallarook would be well suited to large areas of summer-dry hill country. There is a clear need for a white clover cultivar adapted to summer-dry hill country as none of the varieties tested survived severe moisture stress at 2 sites (Hawke's Bay, North Canterbury), and none performed consistently well at the other sites. New Zealand vaneties (Hula, Pitau, G18 and a hill country selection) showed best persistence and production. The overseas cultivars Haifa, Tamar, Louisiana and Clarence Valley, which are all adapted to dry conditions in their country of origin, were consistently poor. Firm selection criteria for dry hill country were not identified, though stolen density and seeding ability should be incorporated and the strong influence of management and soil fertility on genotype performance must be recognised. Keywords: subterranean clover (Trifolium subterraneum L.), white clover (Trifolium repens L.), hill country, dryland, cultivars, persistence, genotype-environmental interaction.

Estimation of time to key phenological stages to guide management of subterranean clover (Trifolium subterraneum L.) in New Zealand

2022 ◽  
Vol 134 ◽  
pp. 126451
Author(s):  
Jing Guo ◽  
Carmen. S.P. Teixeira ◽  
James Barringer ◽  
John G. Hampton ◽  
Derrick J. Moot
Keyword(s):  
New Zealand ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Phenological Stages ◽  
Estimation Of Time
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