Natural selection and cyanogenesis in white clover, Trifolium repens

Bishop, J. A.; Korn, Marina

doi:10.1038/hdy.1969.58

Cited by 26 publications

(22 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(1975) who were unable to show differential survival of cyanogenic and acyanogenic seedlings in polymorphic populations. However, their populations were subjected to a wide range of potential selective forces, and even if selective grazing of cyanogenic morphs occurred (and this was not demonstrated), it may have been balanced by other selective constraints as discussed by Foulds and Grime (1972a, b), Foulds and Young (1977), Daday (1965), Bishop andKorn (1969), Ennos (1981) and others. In our experiments, we attempted to isolate the selective effect of one species of mollusc from all other selective constraints on the cyanogenic polymorphism.…”

Section: Discussionmentioning

confidence: 98%

“…Such natural selection may account for the predominance of cyanogenic morphs in south-western regions. It is still not altogether clear why cyanogenic morphs become less common in the north-east, although Foulds and Grime (1972a, b) and Foulds and Young (1977) suggest that various types of edaphic and climatic stress favour acyanogenic morphs in both species, while similar effects have been noted in T. repens by Daday (1965), and Bishop and Korn (1969). Ennos (1981) shows that the Li allele is associated with fitness factors irrelevant to selective grazing in T. repens, including leaf size.…”

Section: Introductionmentioning

confidence: 98%

See 1 more Smart Citation

Differential grazing by the mollusc Arion hortensis Fér. on cyanogenic and acyanogenic seedlings of the white clover, Trifolium repens L.

Horrill

Richards

1986

Heredity

View full text Add to dashboard Cite

The average amount of releasable cyanide in cyanogenic seedlings of white clover was found to increase by a third from age 5 days to age 35 days. Over this period levels of cyanide decrease in cotyledons, but increase in stems and young leaves.The slug, Anon hortensis was introduced to mixed populations of mostly cyanogenic and mostly acyanogenic. seedlings of white clover of known age for 12 hour periods, and grazing levels of known phenotype seedlings was scored according to whether damage to the seedlings was lethal or not. Slugs did not discriminate between seedling phenotypes with respect to grazing. No difference in the level of damage between phenotypes was detected at 5 days age. At 16, 23 and 35 days age, very few grazed cyanogenic seedlings suffered lethal damage, although most grazed acyanogenic seedlings were lethally damaged. At these ages, most seedlings suffering non-lethal damage were cyanogenic.It is concluded that older seedlings of cyanogenic white clover are protected from lethal grazing damage by the slug Anion hontensis. This may influence the frequency of cyanogenic morphs in populations more than discriminatory grazing on adult plants.

show abstract

Section: Discussionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 98%

Differential grazing by the mollusc Arion hortensis Fér. on cyanogenic and acyanogenic seedlings of the white clover, Trifolium repens L.

Horrill

Richards

1986

Heredity

View full text Add to dashboard Cite

show abstract

“…As such a dilution effect would result from the mixed botanical composition of most commercially grazed swards. and as Bishop and Korn (1969) showed no effect of cyanogenic glucoside content on snail and slug species, there appears little prospect for protecting white clover from porina by varying cyanogenic glucoside content.…”

Section: Larval Survivalmentioning

confidence: 96%

Effect of porina caterpillar (wiseanaspp.) infestation on yield and competitive interactions of ryegrass and white clover varieties

Harris

Brock

1972

New Zealand Journal of Agricultural Research

View full text Add to dashboard Cite

The effects of porina larvae infestation from April to September on monocultures and mixtures of Grasslands Ruanui and Manawa ryegrass, and Huia and 4700 white clover, and on mixtures of Ruanui ryegrass and white clover of high or no cyanogenic glucoside content were examined.No effect of species or of white clover cyanogenic glucoside content on larval survival was shown. Larval weight was related to density of surviving larvae and potential yield of the sward.Larvae reduced yield of white clover monocultures more markedly than of other swards, but susceptibility of white clover was buffered in mixture with ryegrass, Manawa was more susceptible than Ruanui ryegrass to porina infestation, which modified their competitive balance. Effects of larvae on herbage and chemical composition were shown.Measurements of herbage yield reduction caused by porina larvae in glasshouse and field experiments are compared, and management techniques which may minimise the effect of porina damage are discussed.

show abstract

“…Many other studies of the cyanogenic polymorphism in T. repens have concentrated on selective factors discriminating between cyanogenic and acyanogenic phenotypes (Bishop and Korn, 1969, Angseesing, 1974, Foulds and Young, 1977, Dritschiio eta!., 1979. The results reported here suggest that besides determining the presence/absence of linamarase the Li locus (or loci in tight linkage disequilibrium) has other selectively important effects on the plant not associated with cyanogenesis, which may influence both phenotype frequency and maintenance of polymorphism at the Li locus.…”

Section: Discussior'tmentioning

confidence: 99%

Manifold effects of the cyanogenic loci in white clover

Ennos

1981

Heredity

View full text Add to dashboard Cite

SUMMARYIn white clover alternate alleles Ac/ac and Li/Il at two unlinked loci determine the presence/absence of cyanogenic glucosides and the enzyme linamarase respectively. Plants possessing both cyanogenic glucosides and enzyme are cyanogenic. Morphological measurements were made on a random sample of plants from a population polymorphic at both loci. Individuals possessing linamarase had larger leaves than those lacking the enzyme. Competition experiments between all phenotypes showed a significant effect of Li phenotype frequency on total yield. Competitive interactions were such as to maintain polymorphism at the Li locus. It is concluded that the pattern of variation at the Ac and Li loci cannot be adequately explained by selection which discriminates between cyanogenic and acyanogenic phenotypes.

show abstract

Natural selection and cyanogenesis in white clover, Trifolium repens

Cited by 26 publications

References 7 publications

Differential grazing by the mollusc Arion hortensis Fér. on cyanogenic and acyanogenic seedlings of the white clover, Trifolium repens L.

Differential grazing by the mollusc Arion hortensis Fér. on cyanogenic and acyanogenic seedlings of the white clover, Trifolium repens L.

Effect of porina caterpillar (wiseanaspp.) infestation on yield and competitive interactions of ryegrass and white clover varieties

Manifold effects of the cyanogenic loci in white clover

Contact Info

Product

Resources

About