Investigation of a Possible Sexual Function Specialization in the Lowbush Blueberry (Vaccinium angustifoliumAiton. Ericaceae)

Evidence of functional gender polymorphisms in a population of the hermaphroditic lowbush blueberry (Vaccinium angustifolium)1This article is part of a Special Issue entitled “A tribute to Sam Vander Kloet FLS: Pure and applied research from blueberries to heathland ecology”.

“…From our study, for tetrads per flower (Table 1) and proportion pollen viability, our means and standard deviations were 1788 ± 994 (range: 320-4615) and 0.87 ± 0.11 (range: 0.61-0.99), respectively. For the same two male variables, Myra et al (2004) reported 1373 ± 851 (range: 2-3242) and 0.83 ± 0.22 (range: 0.21-0.99), respectively. The means and standard deviations were comparable between the two studies for these variables with the exception of approximately 30% higher pollen counts in our study.…”

“…Individual tetrads are approximately 25 µm in diameter. Myra (2004) and Myra et al (2004) presented evidence that a functional gender specialization may be evolving in lowbush blueberry by evidence of some individual clones essentially functioning as females or males. To investigate whether there is evidence for functional gender specialization in a population of randomly chosen clones from the Blueberry Research Farm in Maine, the mean number of ovules per flower and the mean viable microspores per flower were determined for each of 56 clones.…”

“…The difference in pollen quantity could be methodological or could reflect real differences between Maine and Nova Scotia lowbush clones. The study of Myra et al (2004) also included clones with mean tetrads per flower as low as 2, which coupled with some very low values of proportion pollen viability, are highly important distinctions to our study. For example, the range difference in proportion pollen viability for our study was narrower with values from 0.61-0.99 as compared with those of Myra et al (2004) at 0.21-0.99.…”

“…The flowers have a ring of poricidal anthers that incrementally dispense pollen upon successive pollinator visitations and are located well below the flared style upon which a single stigma protrudes through the corolla opening. Myra (2004) and Myra et al (2004) presented evidence that, although the lowbush blueberry bears morphologically hermaphroditic flowers, a functional gender specialization may be evolving by evidence of some individual genotypes (termed clones) essentially functioning as females or males.…”

Floral and reproductive biology of Vaccinium meridionale (Ericaceae) in the Eastern Andes of Colombia.

“…Cuando esta mutación se mantiene en una población y se encuentran plantas "femeninas" junto con plantas hermafroditas, la población se denomina ginodioica. La ginodioecia ya se ha registrado para otras ericáceas como Gaultheria en Nueva Zelanda (9 especies, Delph, Lively, & Webb, 2006) y Ecuador (Middleton, 1991) y V. angustofolium Aiton (Myra, MacKenzie, & Vander Kloet, 2004;Bell, Drummond, & Rowland, 2012). La ginodioecia se considera un estado de transición hacia la dioecia (separación de sexos) y las condiciones más favorables para su establecimiento se dan cuando hay una alta tasa de autogamia y de depresión por endogamia (Charlesworth & Charlesworth, 1978), ambas condiciones observadas en V. meridionale.…”