The extent of south-north pollen transfer in Finnish Scots pine

Abstract

In order to evaluate the possibility of long distance gene flow in Scots pine (Pinus sylvestris L.), we measured the amount and germinability of airborne pollen and flowering phenology in central, northern, and northernmost Finland during 1997-2000. Totally 2.3% of the detected germinable pollen grains were in the air prior to local pollen shedding. The mean number of germinable pollen grains m -3 air per day was lower prior to local pollen shedding, but in the year 2000 there were more germinable pollen grains in the air of central study site prior to local pollen shedding. Prior to the onset of pollen shedding, 7.5% of female strobili which we observed were receptive. On average female strobili became receptive three days earlier than local pollen shedding started. During the period of pollen shedding in the central study site, we detected germinable airborne pollen in the northern site in years 1997, 1999 and 2000. At the northermost site, we detected germinable airborne pollen during the pollen-shedding period of the northern site in 2000. Our detection of germinable airborne pollen and synchrony of strobili maturation from south to north suggest that populations of Scots pine in central and northern Finland may provide genetic material to populations in northern and northernmost Finland, respectively.

Estimating exotic gene flow into native pine stands: zygotic vs. gametic components

“…) and reproductive asynchrony (Varis et al . ), can generate large differences in pollen‐mediated gene flow independently of spatial isolation. Similar considerations would apply to explain observed differences in male gametic gene flow between the two adjacent P. sylvestris areas.…”

Intrapopulation variation in flowering phenology and fecundity of silver birch, implications for adaptability to changing climate

“…For example, in Scots pine (Pinus sylvestris L.) the female strobili have been observed to become receptive on average 3 days earlier than local pollen shedding starts (Varis et al, 2009). Thus Scots pine may have greater chances for long distance gene flow than birch, despite the more dispersive pollen of the latter (cf.…”

“…Thus, sufficient variation to respond evolutionarily to directional environmental changes may be available at present (Hamrick, 2004;Davis et al, 2005). Trees also have a good potential for genetic mobility, especially via pollen (Hamrick, 2004), and pollen mediated gene flow over several hundred kilometres is possible (Varis et al, 2009). Although gene flow generally tends to oppose the effects of local selection and thus limits adaptation, empirical evidence indicates that local adaptation can occur even in the face of relatively high rates of gene flow (Antonovics, 1971;Lenormand, 2002).…”

Wind pollination over mesoscale distances: an investigation with Scots pine

“…It is also recognized that a large proportion of pollen remains viable after such long‐distance transport (Lindgren et al. , 1995; Varis et al. , 2009; Williams, 2010), provided that atmospheric conditions are not very wet or cold (Pulkkinen & Rantio‐Lehtimäki, 1995; Bohrerova et al.…”