Uptake of Pb and Cd by Plant Species: A Review

The use of plants to extract heavy metals from contaminated soil is termed phytoextraction. In recent times, phytoextraction has gained traction as a method for the remediation of spoil soil due to its eco-friendliness and cost-effectiveness. This review study shows how several plant species like Inula viscosa L. artin, Euohorbia dendroides L, Salix Viminalis, Eucalyptus rostrate, Linnum utitatissimum L., Bryopyllum Pinnatum, Cistus salvifolius L, Helichrysium italicum, etc. can be used for the uptake of Lead (Pb) and/or Cadmium (Cd) from contaminated soil. The review demonstrates that the uptake of these heavy metals from soil using selective plant species is effective and efficient.

Resilience of a semi-deciduous shrub, Cistus salvifolius, to severe summer drought and heat stress

Shrubs often form the understorey in Mediterranean oak woodlands. These shrubs are exposed to recurrent water deficits, but how they will respond to predicted future exacerbation of drought is not yet understood. The ecophysiology of the shrub Cistus salvifolius L. was studied over the summer of 2005, which was during a heat-wave superimposed on the most severe drought in the Iberian Peninsula in the last 140 years. Branch water potential fell drastically during the summer, accompanied by stomatal closure and downregulation of PSII, with a concomitant loss of chlorophyll in the leaves. A parallel increase in the ratio of light-dissipating to light-capturing pigments and the proportion of xanthophyll cycle pigments in the de-epoxidated state, along with alterations in the structure of the light harvesting complex, may have reduced the potential for damage to leaves. Substantial increases in leaf tocopherol content during high radiation may have reduced damage from free radicals. Following autumn rains, leaves of the same shrubs showed physiological recovery, indicating the resilience of this Mediterranean species, for which an extremely dry hydrological year with 45% less rainfall than average, did not prevent healthy leaf functioning in response to renewed soil moisture availability.

Callistemon citrinus and Cistus salvifolius, Two New Hosts of Phytophthora taxon niederhauserii in Italy

Bottlebrush (Callistemon citrinus (Curtis.) Skeels., Myrtaceae) and rock rose (Cistus salvifolius L., Cistaceae) are evergreen shrubs native to Australia and the Mediterranean Region, respectively. In the spring of 2003, approximately 2% of a nursery stock of 12-month-old potted plants of C. citrinus and 8% of a nursery stock of 12-month-old potted plants of Cistus salvifolius grown in the same nursery in Sicily, showed symptoms of leaf chlorosis, defoliation, and wilt associated with root and collar rot. A Phytophthora species was consistently isolated from roots and basal stems on BNPRAH selective medium (2). One isolate from rock rose (IMI 391708) and one from bottlebrush (IMI 391712) were characterized. On potato dextrose agar (PDA), the colonies showed stoloniform mycelium and irregular margins; on V8 juice agar (V8A), colonies were stellate to radiate. Minimum and maximum temperatures on PDA were 10 and 35°C, respectively, with the optimum at 30°C. Mean radial growth rate of isolates on this substrate was 9.9 and 11.3 mm/day, respectively. In saline solution (1), both isolates produced catenulate hyphal swellings and ellipsoid, nonpapillate, persistent sporangia with internal proliferations and dimensions of 52 to 70 × 30 to 42 μm and 51 to 85 × 39 to 45 μm. Mean l/b ratio of sporangia for both isolates was 1.8 ± 1. On V8A plus β-sytosterol, both isolates produced amphyginous antheridia and spherical oogonia in dual cultures with an A2 tester of P. drechsleri Tucker. Conversely, they did not produce gametangia with an A1 tester of P. cryptogea Pethybr., indicating they were A1 mating type. The internal transcribed spacer (ITS)-rDNA sequences of rock rose and bottlebrush isolates showed 100% similarity with those of two reference isolates of P. taxon niederhauserii from GenBank (Accession Nos. FJ648808 and FJ648809). On the basis of the analysis of the DNA, the species isolated from bottlebrush and rock rose were identified as Phytophthora taxon niederhauserii. Pathogenicity tests were carried out on 6-month-old potted plants of C. salvifolius and C. citrinus (10 plants of each plant species for each isolate) transplanted into pots (12 cm in diameter) containing a mixture of 1:1 steam-sterilized, sandy loam soil (vol/vol) with 4% inoculum produced on autoclaved kernel seeds. Plants were maintained at 25 to 28°C and watered to soil saturation once a week. After 2 to 3 weeks, all inoculated plants developed symptoms identical to those observed on plants with natural infections. Ten control plants transplanted into pots containing noninfested soil remained healthy. P. taxon niederhauserii was reisolated solely from inoculated plants. To our knowledge, this is the first report of P. taxon niederhauserii on C. citrinus and C. salvifolius in Italy. This Phytophthora taxon has been reported recently on rock rose in Spain (3). References: (1) D. W. Chen and G. A. Zentmyer. Mycologia 62:397, 1970. (2) H. Masago et al. Phytopathology 67:425, 1977. (3) E. Moralejo et al. Plant Pathol. 58:100, 2009.

Contribución para la caracterización bioclimática del Norte de Portugal. La transición florística atlántico-mediterránea

RESUMEN. Contribución para la caracterización bioclimática del norte de Portugal. La transiciónflorística atlántico-mediterránea. Este trabajo se incluye en la serie de trabajos ya iniciados por Crespíet al. (2001), con el objetivo de contribuir al conocimiento bioclimático del Norte de Portugal, através de la información florística presente. En este sentido, y para proceder a una posible cartografiade las áreas biogeográficas naturales desde una perspectiva termopluviométrica, son ahora introducidos39 nuevos táxones para la relación ya existente. Los táxones analizados en esta aportación son: Anthemistriumfetti f. flosculosa, Arnica montana subsp. atlantica, Aster aragonensis, Carduus bourgeanus,Carduus carpetanus, Carduus platypus subsp. platypus, Carduus platypus var. granatensis, Carduuspycnocephalus, Centaurea cyanus, Centaurea geresensi, Centaurea herminii subsp. herminii, Centaurealangeana, Centaurea rivularis, Centaurea triumfetti subsp. lingulata, Leucanthemopsis pallida subsp.flaveola, Leucanthemopsis pallida subsp. pulverulenta, Leuzea rhaponticoides, Phalacrocarpumhoffmannseggii, Santolina rosmarinifolia, Santolina semidentata, Arbutus unedo, Cistus ladanifer,Cistus laurifolius, Cistus populifolius, Cistus psilosepalus, Cistus salvifolius, Erica arborea, Ericaaustralis, Erica ciliaris, Erica cinerea, Erica lusitanica, Erica scoparia, Erica tetralix, Erica umbellata,Halimium lasianthum subsp alyssoides, Halimium lasianthum subsp lasianthum, Halimium ocymoides,Halimium umbellatum subsp umbellatum, Halimium umbellatum subsp. viscosum. De modo a poderalcanzar los objetivos propuestos, se procede a la aplicación de una rutina programática multivariada,basada en un sistema de información geográfico (SIG), a partir del cual cada uno de los táxonesestudiados es georeferenciado sobre cartografía ambiental (confeccionada y publicada por el Institutopara a Conservação da Natureza, del Ministerio del Ambiente portugués), comparándola después conlas caracterizaciones fitoclimáticas de Franco (1994) y de Costa et al. (1998). Los resultados obtenidosconfirman no sólo un acusado efecto gradual de transición entre el área de influencia bioclimáticaatlántica y la mediterránea, como además la existencia de una tendencia de comportamientofitoclimático intermedio, no considerada hasta el momento en las caracterizaciones bioclimáticas yapublicadas.Palabras clave. Taxonomía, distribución, SIG, caracterización bioclimática.ABSTRACT. Approach on the climatic characterization for Northern of Portugal. The atlanticmediterraneanfloristic transition. Thirty-nine specific and infraspecific taxa with different occurrencesin the continental portuguese area are referred in the present work. In the light of these behaviours,the climatic and geomorphological variability of the North of Portugal has been importantenvironmental factors to explain the floristic diversity in this part of the country. In this case, the taxaanalysed are: Anthemis triumfetti f. flosculosa, Arnica montana subsp. atlantica, Aster aragonensis,Carduus bourgeanus, Carduus carpetanus, Carduus platypus subsp. platypus, Carduus platypus var.granatensis, Carduus pycnocephalus, Centaurea cyanus, Centaurea geresensi, Centaurea herminiisubsp. herminii, Centaurea langeana, Centaurea rivularis, Centaurea triumfetti subsp. lingulata,Leucanthemopsis pallida subsp. flaveola, Leucanthemopsis pallida subsp. pulverulenta, Leuzearhaponticoides, Phalacrocarpum hoffmannseggii, Santolina rosmarinifolia, Santolina semidentata,Arbutus unedo, Cistus ladanifer, Cistus laurifolius, Cistus populifolius, Cistus psilosepalus, Cistussalvifolius, Erica arborea, Erica australis, Erica ciliaris, Erica cinerea, Erica lusitanica, Ericascoparia, Erica tetralix, Erica umbellata, Halimium lasianthum subsp alyssoides, Halimium lasianthumsubsp lasianthum, Halimium ocymoides, Halimium umbellatum subsp umbellatum, Halimiumumbellatum subsp. viscosum. Because of the appropriate management of the floristic richness, amultivariate statistic routine is applied on a Geographical Informatic System (GIS) the chorological,geomorphological and climatic characterization for each one are described in this paper. The geologicalsubstrate and the altitudinal classes are focused for the geomorphological approach, as well as twobiogeographic classifications are used to correlate the occurrence of the taxa and their bioclimaticpreferences. In the light of this analytical scheme, every taxa is geo-referenced upon an environmentalcartography (elaborated by the Instituto para a Conservação da Natureza), compared with the Franco´s(1994) and Costa´s et al. (1998) phytoclimatic characterizations. The results obtained are pointingout the floristic progressive differentiation between the atlantic bioclimatic influence and themediterranean one, as well as the existence of an intermediate bioclimatic tendency which had neverbeen considered so far.Key words. Taxonomy, distribution, GIS, environmental characterization