Pincheira-Ulbrich¹ J, JR Rau², E Hauenstein³

Phyton-International Journal of Experimental Botany, Vol.77, pp. 321-326, 2008, DOI:10.32604/phyton.2008.77.321

Abstract We sampled the diversity of trees and shrubs, and built the rarefaction and accumulation species curve in 10 native forest fragments in southern Chile. Results indicated that: (1) there were 23 species in all sampled fragments, (2) species richness increased significantly with fragment size, (3) all fragments require a minimal sampling from 40 to 170 individuals to reach the maximum theoretical species richness, and (4) sampling richness was greater than that theoretically expected (20 species). More >

Castellanos-Pérez¹ E, AG de Soyza², GB Donart³

Phyton-International Journal of Experimental Botany, Vol.77, pp. 297-320, 2008, DOI:10.32604/phyton.2008.77.297

Abstract The study was conducted in the Chihuahuan Desert Rangeland Research Center, 32 km north of Las Cruces, NM, USA. Physiological responses of the shrub Larrea tridentata (DC) Cov. and the perennial grass Muhlenbergia porteri Scribn were determined from the summer 1997 to the winter 1998-99 when they grew together. In the summer 1997, Larrea tridentata competed for water with M. porteri, as shrubs growing alone showed higher integrated photosynthesis than shrubs in competition with M. porteri following a heavy rainfall event. Larrea tridentata had lower water use efficiency (WUE) than M. porteri plants. In the summer 1998, M. porteri had… More >

Bucciarelli A, VN Cambi, CB Villamil

Phyton-International Journal of Experimental Botany, Vol.77, pp. 283-295, 2008, DOI:10.32604/phyton.2008.77.283

Abstract Araujia hortorum (“tasi”) is a native species of South America, invading crops in several countries. It is used as food and in medicine due to its galactogenic properties. Morphoanatomical and micrographic characters of leaves, stems and roots were studied to determine diagnostic characters that allow its identification in the vegetative state. Stomata and palisade parenchyma indexes, stomata location, the proportion and characteristics of palisade and spongy parenchyma and the scarce quantity of idioblasts, resulted in the most relevant, differential characters. More >

Pérez-Amador¹ MC, V Muñoz Ocotero¹, S Pérez Benitez¹, F García Jiménez²

Phyton-International Journal of Experimental Botany, Vol.77, pp. 275-282, 2008, DOI:10.32604/phyton.2008.77.275

Abstract The presence of phototoxic compounds in stems and leaves of young plants of Vernonia patens Kunth was confirmed by TLC. These compounds were in smaller amounts in younger than in adult plants of this species. Only the stems presented specific activity of these compounds from the two study plant organs. It included characteristic UV bands at 200 and 300nm, and phototoxic activity against Bacillus subtilis (ATCC-6633). Stems and leaves of Vernonia patens also showed anti-inflammatory activity and bactericide potential. More >

Miravalles¹ M, V Beaufort², F Möckel¹

Phyton-International Journal of Experimental Botany, Vol.77, pp. 263-273, 2008, DOI:10.32604/phyton.2008.77.263

Abstract Blackpoint incidence was assessed on grain from six durum wheat (Triticum durum Desf.) varieties grown during crop season 2004-05 at four sites, in the traditional durum wheat growing region of Argentina. Broad differences in grain discolouration were detected among sites and varieties, together with significant variety x site interactions. Among varieties, those with lower thousand grain weight and higher widthto- length ratio (proportionally shorter grains) showed less susceptibility to this disease than heavy/large grain varieties. Differences among sites in the levels of blackpoint incidence were also related to the physical attributes of grains revealing the strong influence of the environment… More >

Sacristán M, AM Millanes, B Fontaniella, ME Legaz, C Vicente

Phyton-International Journal of Experimental Botany, Vol.77, pp. 253-262, 2008, DOI:10.32604/phyton.2008.77.253

Abstract Secreted arginases from Evernia prunastri and Xanthoria parietina thalli, exhibiting lectin activity, have been purified to homogeneity. Analyses of both amino acid and glycoside composition are reported. Purified proteins have been subjected to tryptic digestion and some amino acid sequences have been analyzed. An undecapeptide from Evernia arginase, which shows some degree of homology with the domain to which Mn²⁺ binds, a heptapeptide and an undecapeptide from Xanthoria arginase have been analyzed, and homologies with some arginases from other fungi and plants have been found. More >

Hernández-Castillo¹ FD, RH Lira-Saldivar², L Cruz-Chávez¹, G Gallegos-Morales¹, ME Galindo-Cepeda¹, E Padrón-Corral¹, M Hernández-Suárez²

Phyton-International Journal of Experimental Botany, Vol.77, pp. 241-252, 2008, DOI:10.32604/phyton.2008.77.241

Abstract Potato crop requires more fungicides than any other crop in Mexico to prevent and control several diseases. More than 21,3% of the total available fungicides are required for cropping potato. High quantities of synthetic pesticides are intended to control Phytophthora infestans and Rhizoctonia solani fungi. As a result, this produces severe health problems and ecosystem disturbances. There is then an urgent need for finding new options for sustainable management of potato crop diseases. Several experiments were conducted under laboratory, greenhouse, and field conditions, to: (1) analyze the antifungal effect of bacteria strains of the genus Bacillus, and their effect on… More >

Torres¹ YA, MA Long², SM Zalba¹

Phyton-International Journal of Experimental Botany, Vol.77, pp. 225-240, 2008, DOI:10.32604/phyton.2008.77.225

Abstract The objective of this work is to contribute to the biology of Pavonia cymbalaria A. St. Hil & Naudin (Malvaceae), a native species of the Southern mountains of Buenos Aires Province. This knowledge will contribute to (1) promote its use as an ornamental species, (2) its conservation and (3) stimulate the interest and public valuation of mountain systems biodiversity. Seven populations of P. cymbalaria were selected. Two of them were growing under Pinus halepensis forests to characterize different environments were the herbaceous species is growing in the wild. Environmental characteristics immediately associated to six individuals of the species were studied… More >

Lutz EE, HD Merchán, AE Morant

Phyton-International Journal of Experimental Botany, Vol.77, pp. 217-223, 2008, DOI:10.32604/phyton.2008.77.217

Abstract Forage and grain production of an early sown, long-cycle wheat variety (ProINTA Super) was compared to that in its association with a short-cycle wheat variety (Buck Pronto), both varieties exposed to one or two defoliations. The purpose was producing an earlier and greater amount of dry matter in a dual-purpose wheat. Research was conducted in the Asociación de Cooperativas Argentinas experimental field (38º 36´ S, 61º 58´ W, 122 masl), 15 km SW from Cabildo (Bs. As), in the semi-arid V South wheat subregion. Experimental plots, 7 rows 4m long each and 0,20 m apart from each other, were seeded… More >

Ruíz^1,2,* BC, CA Laguna², ALG Iglesias³, A Damon⁴, HTNJ Marín⁵, RHS Azpíroz⁵, MJL Moreno¹

Phyton-International Journal of Experimental Botany, Vol.77, pp. 203-215, 2008, DOI:10.32604/phyton.2008.77.203

Abstract Encyclia adenocaula (La Llave & Lex.) Schltr. (Orchidaceae) is an epiphyte orchid, which uses oak (Quercus sp) trees as a natural host and is thus considered a non timber-yielding forest resource. Predation of this species is high because of the beauty of its flowers. The Official Mexican Norm (NOM-059-SEMARNAT-2001) reports it as an endemic endangered species in Mexico. The objective of this research was to (1) establish an effective protocol for in vitro germination of immature seeds of this species, and (2) determine the effect of the capsule maturity state on seed germination. The in vitro cultivation mediums were: Murashige… More >