Self-incompatibility, floral parameters, and pollen characterization in the narrow endemic and threatened species <i>Artemisia granatensis</i> (Asteraceae)

Abstract

Peñas, J., Lorite, J., Alba-Sánchez, F. & Taisma, M.A. 2011. Selfincompatibility, floral parameters, and pollen characterization in the narrow endemic and threatened species Artemisia granatensis (Asteraceae). Anales Jard. Bot. Madrid 68(1): 97-105.Artemisia granatensis Boiss. is a paradigmatic species for plant conservation in Spain and Europe. It is a critically endangered (CR) endemic species growing above 2500 m in the Sierra Nevada (southern Spain). Natural populations have been considerably devastated in the past due to intensive human exploitation for folk medicine. The sparse available data concerning the reproductive biology of this species under natural conditions indicate a low reproductive success. To provide additional information on the reproductive biology of A. granatensis, and consequently information useful for the management and conservation of this species, we studied the breeding system through pollen-tube growth. In addition, some floral and pollen traits were recorded. No differences were found between populations in terms of the morphological traits of flowers and inflorescences. A. granatensis is an anemophilous species, and the data indicate that pollen transfer may be limited between isolated populations, and so contributing to an extremely low fruit-set. Results show A. granatensis is selfincompatible, probably with a sporophytic self-incompatibility system, and with no evidence of partial self-incompatibility. Reproductive traits, related to pollen morphology and settling speed may explain the low rate of recruitment in the small populations separated by geographical barriers.Keywords: reproductive biology, pollen-tube growth, endemic and threatened species, conservation. Artemisia granatensis Boiss. es una especie paradigmática en la conservación de flora a nivel español y europeo. Es una especie catalogada como En Peligro Crítico (CR) endémica de Sierra Nevada (sur de España), donde habita por encima de los 2500 m. Las poblaciones naturales han sido casi exterminadas en el pasado debido a una recolección masiva de la especie, utilizada en medicina popular. Los escasos datos disponibles acerca de su biología reproductiva en condiciones naturales indican que existe un bajo éxi to reproductivo. Con el objetivo de proporcionar información adicional acerca de la biología reproductiva de A. granatensis, útil para la conservación y el manejo de la especie, evaluamos el sistema de compatibilidad a través del crecimiento del tubo polínico. Además se registraron datos sobre algunos rasgos florales y polí-nicos de la especie. No se encontraron diferencias entre poblaciones en términos de rasgos morfológicos de flores e inflorescencias. A. granatensis es una especie anemófila para la cual los datos obtenidos sobre capacidad de dispersión sugieren que la transferencia de polen podría ser difícil entre poblaciones aisladas o muy distanciadas, pudiendo ser un factor más a tener en cuenta entre las causas que provocan un limitado éxito reproductivo y una paupérrima producción de semillas. ...

Asian origin and upslope migration of Hawaiian Artemisia (Compositae–Anthemideae)

“…Ferreira et al, 1997;Peñas et al, 2011). Pacifica) was likely to be Asian, as also resolved by parsimony mapping.…”

“…Data on the mating system of Hawaiian Artemisia may allow for more insight into initial colonization of the islands, especially in light of documentation of both self-incompatibility and self-compatibility in the genus (e.g. Ferreira et al, 1997;Peñas et al, 2011).…”

Flower morphology and floral sequence in Artemisia annua (Asteraceae)1

“…The palynological features of A. annua observed in the present study are typical for that described for related genera in the Asteraceae. A similar pollen type with three colpi and pores was described for A. absinthium (Konowalik and Kreitschitz, 2012) and A. granatensis (Penas et al, 2011). In a study comparing Artemisia and related genera, pollen was similarly 3‐zonocolporate, isopolar with radial symmetry, and microechinate (Martin et al, 2001).…”

Evaluation of Inflorescence Visitors as Pollinators of <I>Echinacea angustifolia</I> (Asteraceae): Comparison of Techniques

“…Evidently this induced localized accumulation of callose at the stigma prevents penetration of self-pollen tubes (Vithanage and Knox 1977, Hiscock et al 2002, Friedman and Barrett 2008, Peñ as et al 2011. Other approaches for similar investigations of cross pollination in Asteraceae could involve determination of stigmatic pollen loads within insect-exposed heads after presentation of receptive pistillate ßorets residing on the headÕs perimeter in advance of pollen release from the central whorls of hermaphroditic ßorets in gynomonoecious species like Artemisia granatensis (Pe-ñ as et al 2011), or use of completely male-sterile lines (e.g., sunßower; Vear et al 1990).…”