The importance of seeds and sexual reproduction in the population biology of Cirsium arvense ‐ a literature review

Abstract

In this review the available information on the sexual reproduction of Cirsium arvense L. (Scop.) is summarized and discussed ia an ecological context. Certain aspects of its sexual reproduction system have given C. arvense a reputation for low efficiency: the dioecious mating system and dependence on insects for poilination and non-adaptive features for wind dispersal. The seeds are moderately persistent in soil and, for a temperate weed, have a high temperature requirement for germination. It is concluded that the contribution that sexual reproduction makes to the survival and spread of this species has heen underestimated, partly owing to an inadequate number of studies. Seedling recruitment via sexual reproduction may be an important mechanism for initiating continued genetic diversity at intra-and inter-population levels. efeienoe Havdeti, 1934 Bakker. lWO Denchdd & Sdwltz, l%0 Amm &. Harfis, 1974 Bostock & Bentco, I9T9 van Leeuwen. 1987 f UDstiatfed, without competitkiii, rather moist day loam, aerated lo a depth of 30-40 cm, maJe C. arvense within 20 m. Sd, light iiStoiisity in July 35-45% of full day light, riidier moist da> laiuii,aeTale<lti]adepCbof50cm, maleC nrvensrwithin ETwD «Mu«iit fielck with tlie leoODd tatiag 'eavih dettei gicwingcoiiditiaiiiB'.

Comparing the reproductive success and pollination biology of an invasive plant to its rare and common native congeners: a case study in the genus Cirsium (Asteraceae)

“…Bell et al 2002;Münzbergová 2005), while others, such as Cirsium vulgare, are of conservation concern because they are noxious weeds (Tenhumberg et al 2008). Cirsium species display a wide range of mating systems, from autogamous to xenogamous (van Leeuwen 1981; Keddy and Keddy 1984;Lalonde and Roitberg 1994;Heimann and Cussans 1996), and may differ in their identity and frequency of floral visitors, and thus their reproductive success.…”

Intraspecific plant density effects inCirsium arvense

“…Where plants grow in close proximity they interfere with each other through processes such as competition and allelopathy (Harper 1977), and their response to increasing density of their own kind may be reduced growth, reduced fecundity or death. Because C. arvense reproduces both sexually through seed (Heinmann & Cussans 1996) and asexually through "adventitious" root buds (Hamdoun 1970), population regulation may potentially occur in many ways. In the current experiment we use transplants established from seed as analogues of plants arising from the "adventitious" shoots that characterise pasture populations of the thistle, and assume that plants originating in these two different ways behave the same with respect to crowding.…”

A conceptual model for the population dynamics ofCirsium arvensein a New Zealand pasture

“…It is almost perfectly dioecious with separate male and female plants (Lalonde & Roitberg 1994). Pollination is by insects and seed production is common in female clones (Lalonde & Roitberg 1994;Heinmann & Cussans 1996) with much of this being deposited close to the parent plant (Sagar & Rawson 1964;Wallace et al 2005). C. arvense plants perennate and spread via a creeping root system from which root buds give rise to adventitious shoots (McAllister & Haderlie 1985a).…”

“…Our aim is to develop a framework (conceptual model) for understanding, and ultimately modelling in detail, the population dynamics of C. arvense in pasture. We focus on asexual processes since the seeds of this species, while they undoubtedly can initiate new populations at the time of pasture establishment (Heinmann & Cussans 1996), contribute little to the population dynamics in established pastures (Amor & Harris 1975;Bourdoˆt et al 1995;Edwards et al 2000Edwards et al , 2005Bourdoˆt et al 2006).…”