New protocol for storage of viable pollen of Lapageria rosea (Philesiaceae), an endangered plant species endemic to temperate forests of Chile

Abstract

Lapageria rosea is an emblematic species, endemic to the temperate rainforest of Chile. As a result of extensive plantation of commercial exotic pine and eucalypts, scattered individuals of L. rosea are now encountered mainly in fragmented forest areas. Therefore, L. rosea has been declared in danger of extinction. However, the success of national conservation programs depends, in part, on the availability of stored viable pollen grains for pollinating assays, in order to sustain the genetic diversity of L. rosea offspring. Here we describe a simple and low-cost protocol for storing viable pollen grains for 1 year. The protocol involves oven-drying freshly collected pollen grains at 37 C for 15 min, followed by storage at-13 C. The stored pollen has an average of 60-65% in vitro germination after 5 months, with a reduction to 50% by the end of

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

“…The self-incompatible breeding system, isolation of individuals and out of sync flowering associated with M. bartlettii makes the storage of pollen an essential part of its overall conservation strategy. Short-and long-term storage of pollen allows for cross pollination between trees that flower at different times or grow in different areas (Cruzatty et al 2020). Studies investigating pollen viability and long-term storage for Myrtaceae have mostly focused on species of commercial interest such as various Eucalyptus species (e.g.…”

“…In vitro germination of pollen can provide an effective method for viability assessment, although the germination media and incubation time need to be optimised for each species (Page et al 2006;Cruzatty et al 2020). The ability to extend pollen longevity through short-or long-term storage can be used to overcome temporal and geographical separation of flowering plants (Page et al 2006;Nadarajan et al 2018) and has been instrumental in the conservation of threatened species such as Hymenoxys acaulis var.…”

Reduced Pollination Efficiency Compromises Some Physicochemical Qualities in Gac (Momordica cochinchinensis Spreng.) Fruit

“…However, to achieve the target moisture content, once determined for Gac, further research is required to develop a simple and low-cost protocol suitable for rural areas where it is grown, such as in Vietnam and Thailand. One successful approach, used for pollen conservation of an endangered species (Lapageria rosea) in Chile, compared drying pollen at either 37 • C in an oven, or dehydration in a desiccator containing granulated silica gel for several defined periods prior to storage in a refrigerator, freezer or at ambient temperature for several months [29]. It determined that oven drying pollen for 15 min and storage at −13 • C achieved 60-65% germinability for 5 months and paved the way for hand pollination techniques to be developed.…”

Water deficit influence upon pollen grain production in cacao genotypes (Theobroma cacao)

“…structures, such as filaments, are essential in transporting water and nutrients to pollen-bearing teak, which allows the passage of essential substances involved in the turgor processes of the pollen cell wall (Pacini and Dolferus, 2019). On the contrary, when there is not enough water the pollen grains dry out because of not being able to store water in their vacuoles, resulting in their dissection and death; in other cases, they lose viability, becoming unable to germinate (García et al, 2015;Jalca et al, 2019;García et al, 2020b).…”