Pollen viability in Quercus robur L.

Abstract

The variability of viability (germination rate and the length of pollen tubes) of fresh pedunculate oak (Quercus robur L.) pollen grains was studied in vitro on a medium containing 15% sucrose. Spatial variability was studied by sampling fresh pollen grains from a total of thirteen trees at four different sites in the area of Belgrade (Kosutnjak, Banovo Brdo, Ada Ciganlija and Bojcin Forest) in a single year (2011). In order to assess temporal variability and determine the effects of climate change on a small time scale, we studied the viability of the pollen grains collected from one tree at the Banovo Brdo site in six different years (2004, 2005, 2006, 2007, 2011 and 2012). Interindividual variability was tested on the pollen grains sampled from eight trees at Ada Ciganlija in 2004. The percentage values of the pollen grain germination rate and the pollen tube length showed no statistically significant differences between the sites. However, the studied characteristics of the pollen grain viability (germination rate and pollen tube length) showed statistically significant differences in both temporal (between the pollen collection years) and interindividual variability. This type of research makes a valuable contribution to pedunculate oak breeding programs through the identification of trees with stable production and a good quality of pollen. Furthermore, it can be important in defining the patterns of spatial, temporal and individual variability of pollen grain viability under the influence of climate factors, which are showing compelling changing trends from year to year.

Pollen Production of Quercus in the North-Western Iberian Peninsula and Airborne Pollen Concentration Trends during the Last 27 Years

“…Our study showed the amount of pollen produced by individual members of six oak species, which is approximately summarized in the proportions 1:1:2:5:90:276 for Q. ilex, Q. faginea, Q. rubra, Q. suber, Q. pyrenaica and Q. robur respectively. Previous studies have rarely focused on pollen production in the two more prominent species (Q. robur and Q. pyrenaica) represented in oak forests of North-western Spain; they only examined their pollen viability characteristics [39]. Some research has been conducted in order to measure the pollen production of Q. ilex [11,24], Q. suber and Q. faginea [11] in the Mediterranean basin.…”

Study of the Pollen Grain Metabolome under Deposition of Nitrogen and Phosphorus in Taxus baccata L. and Juniperus communis L.

“…The effect of pollen quality and quantity can have a wide-ranging impact on the reproduction of wind-pollinated trees, as pollen grains can migrate for very long distances [18][19][20]. Therefore, changes in pollen grain productivity and quality can have an ecological and evolutionary impact on the future of plant populations [21][22][23]. Pollen quality can be described in terms of volume or shape, pollen tube growth, enzymatic activity, and the carbon-to-nitrogen ratio [12,[24][25][26].…”

The Cryobiotechnology of Oaks: An Integration of Approaches for the Long-Term Ex Situ Conservation of Quercus Species

“…The levels of nutrients, sucrose and agar influence pollen germination and need to be determined and adjusted per species. In the case of Quercus sp., pollen germination media usually contains 10-20% sucrose and is often solidified with 0.75-1% agar ( [48,49,51,56] for Q. coccinea, Q. petraea and Q. robur). Sometimes mineral nutrients have been added to the basic sucrose solutions, such as 20 ppm boron for Q. alba, Q. coccínea, and Q. ilicifolia [46] or MS salts for Q. robur [56].…”