Progress in recurrent selection and in crossing cultivars with white clover resistant to the clover root‐knot nematode Meloidogyne trifoliophila

  title={Progress in recurrent selection and in crossing cultivars with white clover resistant to the clover root‐knot nematode Meloidogyne trifoliophila},
  author={C. F. Mercer and J J van den Bosch and Kylie Miller},
  journal={New Zealand Journal of Agricultural Research},
  pages={41 - 48}
Abstract New Zealand pastures are generally deficient in clover content due in part to root‐invading nematodes. A recurrent selection programme for resistance to the clover root‐knot nematode (Meloidogyne trifoliophila) assessed individual white clover (Trifolium repens) genotypes for the number of root galls and root dry weight. Low galling (resistant) and a few high galling (susceptible) genotypes were crossed to provide divergent selections and progeny screened. In the sixth generation, the… 

Effects of Nematicides and Plant Resistance on White Clover Performance and Seasonal Populations of Nematodes Parasitizing White Clover in Grazed Pasture

Root-infecting nematodes are a major cause of white clover, Trifolium repens, not reaching its potential in New Zealand pastures. Resistance and/or tolerance are the preferred control options.

Effects of nematicides and plant resistance on white clover performance and seasonal populations of nematodes parasitizing white clover in grazed pasture.

Greenhouse-based, recurrent selection programs have developed resistance to Meloidogyne trifoliophila and Heterodera trifolii, and a field-based program has developed tolerance, and selections from the breeding programmes have exhibited strong agronomic potential across locations and years.

Genetic mapping of a root-knot nematode resistance locus in Trifolium

Genotypes exhibiting either complete resistance or susceptibility to infection by the clover root-knot nematode, Meloidogyne trifoliophila, were identified and segregation analysis indicated the resistance phenotype may be conferred by a single dominant allele at a locus subject to segregation distortion.

Resistance in Trifolium repens and T. semipilosum to Meloidogyne trifoliophila (Nematoda: Tylenchida) is temperature sensitive

The breakdown of resistance to the clover root‐knot nematode at these temperatures exacerbates the constraints already placed on clover productivity by the summer drought.

Performance of nematode-resistant white clover in field trials

White clover lines developed from three independent breeding programmes were established in field trials and exhibited strong agronomic potential across locations and years and the best material has been crossed, with progeny being assessed in current field trials.

Plant-parasitic nematodes on pasture in New Zealand

Progress made in white clover breeding programs in New Zealand is summarized and advances in genetic mapping and introgression as they affect resistance to nematodes are examined, together with observations which suggest that root-feeding nematode have little impact on yield and that the animal toxicity associated with Anguina seed galls in Australia is absent.

Reaction of Trifolium semipilosum to four species of root-knot nematode (Meloidogyne spp)

It is suggested that T. semipilosum is a source of multiple nematode R loci at loci in Trifolium genomes and to investigate transfer of R alleles from T.SemipILosum to white clover and other economic species.

Resistance Reactions to Meloidogyne trifoliophila in Trifolium repens and T. semipilosum.

The predominant root-knot nematode in New Zealand pastures is Meloidogyne trifoliophila, and a recurrent selection program in Trifolium repens has developed resistance to this species. No data are

Comparison of New Zealand perennial clovers for resilience against common pasture pests

Testing of pest resilience amongst 19 leading commercial or near release New Zealand-bred clover cultivars indicated antifeedant compounds, rather than leaf morphology, are likely responsible for differences in feeding preferences between red and white clovers.

Rate of Genetic Gain for Persistence to Grazing and Dry Matter Yield in White Clover across 90 Years of Cultivar Development

An updated estimate of the rate of change in genotypic value attributable to population improvement in white clover is provided, using a set of 80 cultivars released between 1920 and 2010 by public and private plant breeding programs across 17 countries, in an experiment to evaluate forage yield across three locations in New Zealand.



Third generation progress in breeding white clover for resistance to root-knot nematode

Two resistant and two susceptible genotypes were compared for nematode egg production and there were significant differences between seed lines from the selections for number of galls, root dry weight, visual growth score and galls/gram ofroot dry weight.

Effectiveness of recurrent selection of white clover (Trifolium repens) for resistance to New Zealand populations of clover cyst nematode (Heterodera trifolii)

Results indicate that development of a white clover cultivar resistant to H. trifolii is achievable and that the resistance will be effective against the nematode in most of New Zealand.

Host Range and Distribution of the Clover Root-knot Nematode, Meloidogyne trifoliophila.

The ability of Meloidogyne trifoliophila to gall 230 species and cultivars of plants was determined in a greenhouse and results for Amaryllidaceae, Asteraceae, Lamiaceae, and Liliaceae were variable.

Plant-parasitic nematodes in New Zealand

Nematodes attack a wide variety of economic plants in New Zealand and the extent of crop losses is discussed, including recurrent selection of white clover for resistance, field‐based selection for tolerance, and the study of nematode biology and life cycles.

Plant-Parasitic Nematodes

Prior to the early 1970's, plant parasitic nematodes were known to be responsible for the failure of replanted frui t trees to grow normally in Michigan and for carrots and other root vegetables to fork or be otherwise distorted.

Management of clover in grazed pastures : expectations , limitations and opportunities

The value of white clover as a component of New Zealand pastures is undeniable, but it is also widely recognised that clover has limitations as a pasture plant and that these can lead to