The Breakdown of Trimorphic Incompatibility in Oxalis Section Corniculatae

Ornduff, Robert

doi:10.2307/2406982

Cited by 80 publications

(87 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The only major difference between inheritance of tristyly in section Laxae and section lonoxalis is the complication of polysomic inheritance in some species of section lonoxalis. The genetic system controlling expression of style forms in tristylous taxa of Oxalis section Corniculatae is also similar to the system found in section lonoxalis, although there is no evidence for linkage (Ornduff, 1972). As a result of the self-compatibility which is common in section Corniculatae, homozygous short genotypes are occasionally encountered.…”

Section: Discussiomentioning

confidence: 66%

“…As a result of the self-compatibility which is common in section Corniculatae, homozygous short genotypes are occasionally encountered. Self-pollinations revealed that a short-mid-long sequence of dominance is also found in section Corniculatae (Ornduff, 1972). More significant differences are found in the control of tristyly in Oxalis rosea, where von Ubisch (1926) demonstrated that the short allele was recessive.…”

Section: Discussiomentioning

confidence: 98%

See 1 more Smart Citation

The genetic control of tristyly in Oxalis section Ionoxalis

Weller

1976

Heredity

View full text Add to dashboard Cite

SUMMARYProgeny ratios from crosses utilising six tristylous species of Oxalis section lonoxalis indicate that expression of style forms in this section is generally controlled by two loci which are tightly linked. In diploid species one locus controls the expression of the short style form versus non-short, while the second locus controls the expression of the mid and long style forms. The short allele is epistatic to the mid-long locus, where mid is dominant to long. Control of tristyly is similar in polyploid species, although linkage cannot be detected because of chromosome duplication. Fixation or loss of the mid-long locus would allow the remaining short versus non-short locus to segregate equal numbers of shorts and longs, thus providing a genetic basis for control of distyly.

show abstract

Section: Discussiomentioning

confidence: 66%

Section: Discussiomentioning

confidence: 98%

The genetic control of tristyly in Oxalis section Ionoxalis

Weller

1976

Heredity

View full text Add to dashboard Cite

show abstract

“…What is perhaps more remarkable is the stability of floral trimorphism in the face of these ecological pressures. This is in contrast to several self-compatible tristylous taxa in which extensive genetic modifications to the sexual polymorphism have been documented in association with colonization of marginal or disturbed environments (Ornduff 1972;Barrett 1979;Barrett et al 1989;Eckert and Barrett 1994). It seems likely that the maintenance of a strong trimorphic incompatibility system in L. salicaria serves to buffer the mating system against inbreeding and consequent opportunities for the spread of recessive mutations modifying the sexual polymorphism (Charlesworth 1992;Fenster and Barrett 1994).…”

Section: Morph-frequency Variation In Native Versus Introduced Populamentioning

confidence: 73%

GENETIC DRIFT AND FOUNDER EFFECT IN NATIVE VERSUS INTRODUCED POPULATIONS OF AN INVADING PLANT,LYTHRUM SALICARIA(LYTHRACEAE)

1996

View full text Add to dashboard Cite

Abstract.-There are few convincing examples of genetic drift at loci under selection in natural populations. The plant sexual polymorphism tristyly provides an opportunity to investigate genetic drift because stochastic processes interacting with frequency-dependent selection give rise to a diagnostic pattern of morph-frequency variation. A previous study of 102 Ontario populations of the introduced tristylous wetland herb Lythrum salicaria provided evidence for the role of stochastic processes during colonization. However, whether stochastic effects are greater in these recently introduced populations compared to native Eurasian populations remains unclear. The propensity of this species to invade disturbed habitats suggests that episodes of colonization and periods of small population size must also occur in the native range. A survey of 102 populations in southwestern France indicated reduced stochastic effects in native populations. Populations exhibited significantly lower morph loss than in Ontario (5% vs. 23%) and significantly higher values of morph evenness. The greater incidence of trimorphism in French populations was not associated with larger population sizes; populations were significantly smaller than those in Ontario (means: 266 vs. 487). Morph evenness was positively correlated with population size among French but not Ontario populations, providing further evidence of nonequilibrium conditions in introduced compared to native populations. The incidence of trimorphism was unexpectedly high in small native populations (N:S 25; 22 of 27 populations trimorphic). Computer simulations indicated that levels of gene flow on the order of m 2: 0.05 can account for the maintenance of tristyly in small populations. The high connectivity of populations within the agricultural landscape typical of southwestern France may facilitate levels of gene flow sufficient to maintain trimorphism in small populations.

show abstract

“…and Phillyrea angustifolia [Oleaceae] [Lepart and Dommée, 1992;Yamazaki, 1993;Hiura and Ishida, 1994;Ishida and Hiura, 1998;Dommée et al, 1999] [Ornduff, 1964[Ornduff, , 1972, Saxifraga cernua [Saxifragaceae] [Molau and Prentice, 1992], and Schizopepon bryoniaefolius [Cucurbitaceae] [Akimoto, Fukuhara, and Kikuzawa, 1999]). A few plant species show ''monoecious'' cosexes with pistillate and staminate flowers on the same inflorescences (Ricinocarpos pinifolius and Mercurialis annua [Euphorbiaceae] [Thomson et al, 1989;Pannell, 1997], and Sagittaria lancifolia [Alismataceae] [Muenchow, 1998] (Fig.…”

mentioning

confidence: 99%

Thrips pollination of androdioeciousCastilla elastica(Moraceae) in a seasonal tropical forest

Sakai

2001

American J of Botany

View full text Add to dashboard Cite

Androdioecy is a rare sexual system in nature, as predicted theoretically. Among the androecious species reported so far, Castilla elastica (Moraceae) is unique in that flowers are unisexual and staminate and pistillate flowers on cosexual plants are produced on different inflorescences. In addition, inflorescence structure of staminate inflorescences on males and staminate and pistillate inflorescences on cosexes is markedly different. Staminate inflorescences on males are bivalvate, while staminate inflorescences on cosexes are ''fig-like'' and urceolate. Pistillate inflorescences are discoidal. The difference may reflect different roles and requirements of the three inflorescences in pollination and protection from herbivores. This study reports thrips pollination of C. elastica, demonstrated by a pollinator introduction experiment. Thrips pollination of the species may be an example of mutualism originating from plantherbivore interactions. In the Moraceae, shifts from simple herbivores on flowers to pollinators might have occurred many times, evolving into diverse pollination systems including the fig-fig wasp mutualism. The family, of which little is known about pollination systems, provides interesting and unique opportunities to study evolution of pollination systems and roles of nonpollinating associates of inflorescences.

show abstract

The Breakdown of Trimorphic Incompatibility in Oxalis Section Corniculatae

Cited by 80 publications

References 10 publications

The genetic control of tristyly in Oxalis section Ionoxalis

The genetic control of tristyly in Oxalis section Ionoxalis

GENETIC DRIFT AND FOUNDER EFFECT IN NATIVE VERSUS INTRODUCED POPULATIONS OF AN INVADING PLANT,LYTHRUM SALICARIA(LYTHRACEAE)

Thrips pollination of androdioeciousCastilla elastica(Moraceae) in a seasonal tropical forest

Contact Info

Product

Resources

About