Invasions by alien Carpobrotus spp. have been recognised as one of the most severe threats to Mediterranean climate coastal ecosystems, and Carpobrotus is considered one of the most widespread invasive alien genera in the Mediterranean Basin. The aims of this study were to characterise seed germination of both C. edulis and its hybrid C. aff. acinaciformis, in terms of photoperiod, temperature and salinity. Inter- and intra-specific variability in the responses to photoperiod (12/12 h light and total darkness), constant temperatures (5, 10, 15, 20, 25 °C) and an alternating temperature regime (25/10 °C), salt stress (0, 125, 250, 500 mm NaCl) and the recovery of seed germination were evaluated for two seed lots of C. edulis and two of its hybrid C. aff. acinaciformis. All the tested seed lots achieved higher germination percentages in the light, with respect to total darkness. In relation to temperature, the two C. edulis seed lots did not show a preference, while the two C. aff. acinaciformis seed lots differed in their germination response, one germinating more at the lowest temperatures (5 and 10 °C) and one at the highest (20 and 25 °C). For all seed lots, highest germination occurred without NaCl (0 mm) and germination decreased with increasing salinity. Different germination requirements in a saline substrate were not detected for C. edulis, while they were observed for C. aff. acinaciformis. Marked differences were detected in recovery responses between the two taxa. C. edulis has the ability to germinate over a wide time window throughout the year. This study identified significant differences in seed production, seed mass, germination requirements (temperature) and salinity tolerance for both C. edulis and C. aff. acinaciformis. Our results indicate the extreme versatility of the hybrid forms to germinate in a wide range of natural conditions and habitats.

Inter- and intra-variability of seed germination traits of Carpobrotus edulis N.E.Br. and its hybrid C. affine acinaciformis

Podda L.
Primo
;
Santo A.
Secondo
;
Bacchetta G.
Ultimo
2018-01-01

Abstract

Invasions by alien Carpobrotus spp. have been recognised as one of the most severe threats to Mediterranean climate coastal ecosystems, and Carpobrotus is considered one of the most widespread invasive alien genera in the Mediterranean Basin. The aims of this study were to characterise seed germination of both C. edulis and its hybrid C. aff. acinaciformis, in terms of photoperiod, temperature and salinity. Inter- and intra-specific variability in the responses to photoperiod (12/12 h light and total darkness), constant temperatures (5, 10, 15, 20, 25 °C) and an alternating temperature regime (25/10 °C), salt stress (0, 125, 250, 500 mm NaCl) and the recovery of seed germination were evaluated for two seed lots of C. edulis and two of its hybrid C. aff. acinaciformis. All the tested seed lots achieved higher germination percentages in the light, with respect to total darkness. In relation to temperature, the two C. edulis seed lots did not show a preference, while the two C. aff. acinaciformis seed lots differed in their germination response, one germinating more at the lowest temperatures (5 and 10 °C) and one at the highest (20 and 25 °C). For all seed lots, highest germination occurred without NaCl (0 mm) and germination decreased with increasing salinity. Different germination requirements in a saline substrate were not detected for C. edulis, while they were observed for C. aff. acinaciformis. Marked differences were detected in recovery responses between the two taxa. C. edulis has the ability to germinate over a wide time window throughout the year. This study identified significant differences in seed production, seed mass, germination requirements (temperature) and salinity tolerance for both C. edulis and C. aff. acinaciformis. Our results indicate the extreme versatility of the hybrid forms to germinate in a wide range of natural conditions and habitats.
2018
Carpobrotus; Alien vascular flora; NaCl; Coastal ecosystems; Plant invasions; Recovery
File in questo prodotto:
File Dimensione Formato  
Podda_et_al-2018-Plant_Biology.pdf

Solo gestori archivio

Tipologia: versione pre-print
Dimensione 518.73 kB
Formato Adobe PDF
518.73 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11584/251820
Citazioni
  • ???jsp.display-item.citation.pmc??? 2
  • Scopus 10
  • ???jsp.display-item.citation.isi??? 8
social impact