Effect of storage on pollen viability in Pinus sylvestris L., Pinus mugo Turra and their hybrid swarms

Abstract

Pollen storage is the only way how to overcome the differences in phenology of forest trees and geographically determined reproductive barriers between them during controlled pollination. Pollen viability of Scots pine (Pinus sylvestris L.), mountain dwarf pine (P. mugo Turra) and their hybrid swarms was evaluated after 3-years storage at −20°C using in vitro germination test. One population of each P. sylvestris and P. mugo were involved into study along with three hybrid swarms. Germination potential of the stored pollen grains was reduced significantly in comparison with freshly collected pollen. Profound decrease in germination rate was recorded in the two hybrid swarms (4.0-4.7%), less profound in the remaining three populations (0.6-2.4%). Pollen tube length, as the second pollen viability trait was reduced in stored pollen grains in a larger extend ranging between 51.4% and 54.3%. The pollen grains of the species P. mugo was exception in this respect yielding pollen grains whose growth was retarded of 21.9% only. Analysis of variance confirmed significant differences between fresh and stored pollen grains. Statistically significant were also the differences between compared populations and between tested individuals of the respective populations.

Longevity and germination of Juniperus communis L. pollen after storage

“…The approach based on in vitro germination shed some light on the germination mechanism, contributing simultaneously to characterisation of the pollen viability potential in quantitative terms. The ascertained germination of freshly harvested juniper pollen ranged between 67.3 and 88.6%, which was lower than that of fresh pollen in Pinus sylvestris , P. mugo, and their hybrids (88.2–95.4%) 24 . In a study on the effect of nitrogen fertilisation on the quality of J. communis pollen, a relatively low germination rate in pollen collected from fertilised plants (1.36%) was reported compared with non-fertilised plants (24.9%) 25 .…”

Cross-pollination and pollen storage to assist conservation of Metrosideros bartlettii (Myrtaceae), a critically endangered tree from Aotearoa New Zealand

“…glabra, Brighamia insignis and Pittosporum halophilum (DeMauro 1993;Towill 2004). Although the creation of pollen banks is widely used in crop breeding, it is an underutilised tool for plant conservation and there is an urgent need for the development of species-specific pollen collection and storage protocols (Kormuťák et al 2019).…”