Pollen Viability, Vigor, and Competitive Ability in Erythronium grandiflorum (Liliaceae)

Abstract

To determine how the capability of pollen is affected by lengthy exposure to field conditions, we obtained pollen samples (from Erythronium grandiflorumi that were fresh (from newly dehisced anthers) or aged, from 6 to 24 hr. Without pretreating the collected grains, we compared their abilities I) to retain viability, as indicated by the Heslop-Harrison fluorochromatic reaction (FCR) test; 2) to retain germinability, as indicated by pollen-tube growth in vitro on Brewbaker-Kwack medium; 3) to sire seeds when used as a pollen donor on recipient flowers in the field; and 4) to sire seeds competitively when mixed with another donor pollen in competitive pollinations. FCR scores declined drastically with pollen age. Germinability typically declined with age, but less drastically; the correlation between FCR and germinability ranged from strong to nil in different trials. The sharp decline in FCR was probably due to nonlethal, reversible desiccation. Seed-siring success, both in competitive and noncompetitive trials, bore no relation to pollen age or to germinability. Any loss in seed-siring ability in E. grandiflorum pollen over 24 hr is apparently overwhelmed by other sources of variation. The lack of correlation between seed-siring ability and FCR or germinability scores means that those tests should not be used to estimate overall pollen competence in this species. They should be so used in other species only if experiments have demonstrated their greater reliability.

Viability and germinability in long term storage of Corylus avellana pollen

“…Therefore, the simultaneous use of several tests should be supported in order to evaluate the different features of pollen viability (Dafni and Firmage, 2000;Rodriguez-Riano and Dafni, 2000;Thomson et al, 1994). New applications of microfluidic impedancebased flow cytometry (Cheung et al, 2010;David et al, 2012) are highly promising for the evaluation of pollen viability and have to be considered also for direct applications in agriculture.…”

Reproductive and physiological responses to simulated climate warming for four subalpine species

“…Snow cover on the control plots may provide better insulation from low night-time temperatures compared with any extra warmth the heaters may have provided. Although foliar tissues of E. grandiflorum recover rapidly following freezing (Germino & Smith, 2001; but see Loik et al, 2004), floral tissues appear quite sensitive to temperature (Thomson et al, 1994;Price & Waser, 1998). Loewen et al (2001) found that populations of E. grandiflorum at highelevation sites in British Columbia produced proportionately fewer flowers than low-elevation populations.…”

Pollen‐tube growth rate and seed‐siring success among Betula pendula clones

“…Bjo$ rkman et al, 1995 ;Snow & Spira, 1996) provide evidence for non-random fertilization, the association between pollen tube growth and seed-siring success has not been straightforward (Melser et al, 1997 ; J. I. Hormaza & M. Herrero, unpublished ; see also Thomson et al, 1994). Melser et al (1997) found that the parental combinations that sired relatively many seeds did not have high pollen-tube growth rates in Echium vulgare.…”