Browsing by Subject "Terfezia"

Now showing 1 - 4 of 4
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    Beneficial native bacteria improve survival and mycorrhization of desert truffle mycorrhizal plants in nursery conditions
    (Springer, 2016-06-04) Navarro-Ródenas, Alfonso; Berná Amorós, Luis Miguel; Lozano-Carrillo, Cecilia; Andrino, Alberto; Morte Gómez, María Asunción; Biología Vegetal
    Sixty-four native bacterial colonies were isolated from mycorrhizal roots of Helianthemum almeriense colonized by Terfezia claveryi, mycorrhizosphere soil, and peridium of T. claveryi to evaluate their effect on mycorrhizal plant production. Based on the phylogenetic analysis of the 16S rDNA partial sequence, 45 different strains from 17 genera were gathered. The largest genera were Pseudomonas (40.8 % of the isolated strains), Bacillus (12.2 % of isolated strains), and Varivorax (8.2 % of isolated strains). All the bacteria were characterized phenotypically and by their plant growth-promoting rhizobacteria (PGPR) traits (auxin and siderophore production, phosphate solubilization, and ACC deaminase activity). Only bacterial combinations with several PGPR traits or Pseudomonas sp. strain 5, which presents three different PGPR traits, had a positive effect on plant survival and growth. Particularly relevant were the bacterial treatments involving auxin release, which significantly increased the root-shoot ratio and mycorrhizal colonization. Moreover, Pseudomonas mandelii strain 29 was able to considerably increase mycorrhizal colonization but not plant growth, and could be considered as mycorrhiza-helper bacteria. Therefore, the mycorrhizal roots, mycorrhizosphere soil, and peridium of desert truffles are environments enriched in bacteria which may be used to increase the survival and mycorrhization in the desert truffle plant production system at a semi-industrial scale.
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    Elevated atmospheric CO 2 modifies responses to water-stress and flowering of Mediterranean desert truffle mycorrhizal shrubs
    (2020) Navarro-Ródenas, Alfonso; Peguero-Pina, José Javier; Luigi Guarnizo, Angel; Gil-Pelegrín, Eustaquio; Arenas Jiménez, Francisco; Marqués Gálvez, José Eduardo; Morte Gómez, María Asunción; Biología Vegetal
    Predicted increases in atmospheric concentration of carbon dioxide (CO2) coupled with increased temperatures and drought are expected to strongly influence the development of most of the plant species in the world, espe- cially in areas with high risk of desertification like the Mediterranean basin. Helianthemum almeriense is an ecologically important Mediterranean shrub with an added interest because it serves as the host for the Terfezia cla- veryi mycorrhizal fungus, which is a desert truffle with increasingly commer- cial interest. Although both plant and fungi are known to be well adapted to dry conditions, it is still uncertain how the increase in atmospheric CO2 will influence them. In this article we have addressed the physiological responses of H. almeriense × T. claveryi mycorrhizal plants to increases in atmospheric CO2 coupled with drought and high vapor pressure deficit. This work reports one of the few estimations of mesophyll conductance in a drought deciduous Mediterranean shrub and evaluates its role in photosyn- thesis limitation. High atmospheric CO2 concentrations help desert truffle mycorrhizal plants to cope with the adverse effects of progressive drought during Mediterranean springs by improving carbon net assimilation, intrinsic water use efficiency and dispersal of the species through increased flowering events
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    Spring stomatal response to vapor pressure deficit as a marker for desert truffle fruiting
    (2020) Navarro-Ródenas, Alfonso; Marqués Gálvez, José Eduardo; Morte Gómez, María Asunción; Biología Vegetal
    The cultivation of desert truffle Terfezia claveryi using Helianthemum almeriense as a host plant has recently become a solid alternative crop in the Mediterranean region due to its adaptation to arid and semiarid ecosystems, which are expected to increase during the following years because of climate change. However, management models are still being developed in order to improve and stabilize the production, which varies greatly from one year to another. According to gatherers and farmers, one of the key factors for desert truffle production is the plant phenology in spring, which, in turn, depends on environmental conditions. In this manuscript, we have characterized the physiological, morphological, and molecular responses of the mycorrhizal plants in spring, coinciding with the fructification period of the plant and fungal species. Thanks to this characterization, a sigmoidal relationship between stomatal conductance and vapor pressure deficit (VPD)was found,which can be used as amarker of plant phenological switch. In order to confirmthat this phenology status is related to desert truffle fructification, this marker has been successfully correlated to total truffle production. The results of this manuscript suppose a big step forward that will help to develop management models for the desert truffle crop.
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    The crop of desert truffle depends on agroclimatic parameters during two key annual periods
    (Springer, 2019-11-09) Andrino, Alberto; Navarro-Ródenas, Alfonso; Marqués Gálvez, José Eduardo; Morte Gómez, María Asunción; Biología Vegetal
    Desert truffles have become an alternative agricultural crop in semiarid areas of the Iberian Peninsula due to their much appreciated edible value and their low water requirements for cultivation. Although most studies related to desert truffle production point to the sole importance of precipitation, this work is the first systematic study carried out to characterize whether other important agroclimatic parameters, for example reference evapotranspiration, soil water potential, relative air humidity %, aridity index or air vapour pressure deficit, may have an impact on a desert truffle production in an orchard with mycorrhizal plants of Helianthemum almeriense × Terfezia claveryi for 15 years from the plantation. The results show for the first time that T. claveryi production has two key periods, during its annual cycle: autumn (September to October) and spring (end of March). The aridity index and soil water potential seem to be the most manageable parameters in the field and can be easily controlled by applying irrigation during the abovementioned periods. Agroclimatic parameters can influence the final crop a long time before the desert truffle fruiting season contrary to what happens with other edible mycorrhizal mushrooms. Four different models to manage desert truffle plantations are proposed based on these agroclimatic parameters in order to optimize and stabilize carpophore fructifications over the years.