Browsing by Author "Zavattieri, M. A."
Now showing 1 - 4 of 4
Results Per Page
Sort Options
- Monitoring system and in situ conservation of endemic and threatened Beta patula Aiton populations in Madeira RegionPublication . Nóbrega, H.; Freitas, G.; Zavattieri, M. A.; Ragonezi, C.; Frese, L.; Carvalho, M. A. A. Pinheiro det Madeira Archipelago is a hotspot for crop wild relatives (CWR) of crop cultures. Some of these CWR are present in very specific environments, such as, in Ponta de Sa˜o Lourenc¸o or Desertas Islands. One such species is Beta patula Aiton, a Critically Endan gered species which belongs to the Gene Pool 1b of cultivated beets. A continuous effort has been devel oped for its ex situ conservation through the storage of accessions (ISOP2512 and ISOP1911) in the ISO Plexis GeneBank at the University of Madeira Simultaneously, a series of studies have been carried out to understand the species’ ecogeographic and ecological requirements, to validate populations’ boundaries and sizes, and to establish population dynamics. This study includes a complete floristic survey at the B. patula locations of, Desembar cadouro islet (DI) with 12 (DI1–DI12) sampling sites, and Cha˜o islet (CI) with 3 (CI1–CI3). Several Biodiversity indices were calculated for these loca tions. Plot DI3 exhibited the highest values for Corrected Evenness (E0 = 0.77 ± 0.07), Shannon– Weaver Diversity Index (H0 = 2.48 ± 0.12), and Hill’s Index (N2 = 4.47 ± 0.72), with a total sum of 306 individuals of B. patula. The demographic status of B. patula populations in DI and CI was determined yearly between 2014 and 2018. The results show an average population size of 16,906 and 2917 plants, respectively. These data will be used for the estab lishment of a protocol to monitor and manage a genetic reserve for B. patula and other CWR. By doing so, our work will contribute to the implemen tation of the European genetic reserve network.
- Mycorrhiza-like structures in rooted microshoots of Pinus pinea L.Publication . Castro, M. R.; Ragonezi, C.; Klimaszewska, K.; Lima, M.; de Oliveira, P.; Zavattieri, M. A.Pinus pinea L. (stone pine) is one of the major plantation species in Iberian Peninsula, being Portugal the largest edible seed producer in the world. The induction and improvement of in vitro rhizogenesis of microshoots of Pinus pinea was developed in our laboratory using a co-culture system with ECM fungi. In the acclimation phase in mixed substrates, or in rhizotrons, anatomical and morphological studies were done to observe the evolution of the root system in microshoots from the co-culture system vs. control plants. Extensive dichotomous and coralloid branching of lateral roots occurred spontaneously in inoculated and control plants as well. Moreover, similar branching occurred in liquid culture of excised seedling roots without the presence of ECM fungi. The striking similarity of these organs with pine ectomycorrhizas prompted their anatomical analysis; however the presence of Hartig net was not confirmed. These results suggested that the development of ECM-like structures might have occurred spontaneously.
- O-coumaric acid ester, a potential early signaling molecule in Pinus pinea and Pisolithus arhizus symbiosis established in vitroPublication . Ragonezi, C.; Teixeira, D.; Caldeira, A. T.; Martins, M .R.; Santos-Silva, C.; Ganhão, E.; Klimaszewska, K.; Zavattieri, M. A.During ectomycorrhizal (ECM) establishment, biochemical signals lead to the development of complex structures in both the plant and the fungus that ultimately result in the formation of an ectomycorrhiza. The cross-talk between partners begins before physical contact. Our objective was to investigate the chemical nature of the signals during the first stages of in vitro mycorrhization of Pinus pinea with Pisolithus arhizus. For this purpose a double-phase solid liquid medium was expressly developed for the co-culture in order to simplify the extraction and further molecules analysis. O-coumaric acid ester was identified using HPLC UV and LC DAD MS on the second day of co-culture and its presence was detected for up to 10 days. These results contribute to the characterization of biochemical signals during pre-colonization involving conifer species and an ECM fungus, and demonstrate the suitability of the double-phase medium developed for the growth of both organisms and for the analysis of released chemical mediators.
- Structure and floristic composition associated with an endangered species Beta patula Aiton (Amaranthaceae) in the Islands of Madeira ArchipelagoPublication . Nóbrega, Humberto; Freitas, Gregório; Zavattieri, M. A.; Ragonezi, Carla; Carvalho, Miguel Â. A. Pinheiro deTwenty-two native Crop Wild Relatives (CWR) occur in specific dry environments of Madeira Archipelago, like Desembarcadouro islet in Ponta de São Lourenço and Chão islet in Desertas Islands. Nine of them share the same gene pool with crop species included in Annex I of the International Treaty on Plant Genetic Resources for Food and Agriculture. Amongst them, Beta patula Aiton, an IUCN Critically Endangered species, has been studied in detail for in situ and ex situ conservation. The present paper summarises the information recorded during the Beta patula population assessment. Valuable information on plant communities associated with this species was obtained.