Hernández LF

Phyton-International Journal of Experimental Botany, Vol.79, pp. 109-115, 2010, DOI:10.32604/phyton.2010.79.109

Abstract The relationships between (1) leaf biomass and morphology (lamina area and petiole and lamina inclination), (2) petiole’s mechanical and structural properties, and (3) the vertical light gradient inside the crop’s canopy were studied in field grown sunflower (Helianthus annuus L.) plants, maintained at optimum soil water and mineral levels. At flowering, incident photosynthetic active radiation (PAR) was measured at the top of the canopy and on individual leaves using a quantum sensor. The fraction of direct incident radiation which passed through the canopy reaching each individual leaf was then calculated. Individual petiole and lamina inclination angles (ia_Petiole and ia_Lamin, respectively)… More >

Buentello Volante¹ B, F Díaz de León-Sánchez¹, F Rivera-Cabrera¹, R Aguilar Caballero², M Ponce-Valadez¹, E Sánchez de Jiménez², LJ Pérez-F lores¹

Phyton-International Journal of Experimental Botany, Vol.79, pp. 101-108, 2010, DOI:10.32604/phyton.2010.79.101

Abstract Auxin and insulin promote Zea mays embryo growth, induce S6 ribosomal protein (S6rp) phosphorylation, and promote specific protein synthesis. The objective of this research was to test a possible cross-talk between insulin and auxin transduction pathways in Z. mays coleoptiles, typical auxin target tissues. Auxin and insulin produced differential quantitative and qualitative stimulation of cytoplasmic and ribosomal protein phosphorylation, and specific patterns of de novo synthesized cytoplasmic proteins. In addition, insulin induced S6rp phosphorylation was strongly inhibited by rapamycin, indicating target of rapamycin (TOR) kinase participation; auxin-induced S6rp phosphorylation was insensitive to this inhibitor. Phosphatidic acid (PA), a second messenger… More >

Ixtaina¹ VY y MM Mujica^1,2

Phyton-International Journal of Experimental Botany, Vol.79, pp. 95-100, 2010, DOI:10.32604/phyton.2010.79.095

Abstract The slow initial growth of Lotus tenuis limits its use to improve the Flooding Pampas grasslands by mean of its intersowing. Research on the inter and intra-population variability of seedling vigor under changing environmental conditions, and the population x environment interaction, contribute to design sowing strategies and selection criteria. The objective of this study was to evaluate the inter and intra-population phenotypic variability, under different plant densities and planting dates. Variables measured included the number of stems (Nt), and the shoot dry weight (PSa) in L. tenuis seedlings. Crown stems and PSa were determined in 5 populations in a completely… More >

Alejandre Rosas¹ JA, ME Galindo Tovar², HE Lee Espinosa², OG Alvarado Gómez³

Phyton-International Journal of Experimental Botany, Vol.79, pp. 87-94, 2010, DOI:10.32604/phyton.2010.79.087

Abstract Development of new sugarcane varieties allows to increase sucrose production and faces challenges as new pests and diseases, and soil fertility losses. The objective of this study was to contribute to expand molecular tools in selecting useful progenitors for hybridization programs. With this purpose, 14 RAPDs primers were pre-screened, and four of them which produced clearly resolved, reproducible and polymorphic fragment patterns were selected for genetic analysis of 22 sugarcane variety hybrids. These were used in the Estación de Hibridación at Tapachula, Chiapas, as progenitors in genetic improvement programs. Genetic distance analysis showed three main clusters. The first cluster contained… More >

Liu ZG^1,2, YL Cai^1,2, K Li^2,3

Phyton-International Journal of Experimental Botany, Vol.79, pp. 81-86, 2010, DOI:10.32604/phyton.2010.79.081

Abstract Induced responses to herbivory are physical, nutritional, and allelochemical traits that change in plants following disturbances, and reduce the performance and/or preference of leaf tissues on herbivores. This study gave evidence to the induced defense theory through the simulated herbivory in Schima superba, one of common dominant trees in subtropical evergreen, broadleaf forests in southern China. Results showed that leaves damaged at the beginning of leaf expansion would develop into having a larger area, higher toughness and higher tannin concentrations, but a lower water content compared with control leaves. As a result, they experienced lower herbivory rates than controls. These… More >

Pérez-Amador¹ MC, V Muñoz Ocotero¹, R Ibarra Balcazar¹, F García Jiménez²

Phyton-International Journal of Experimental Botany, Vol.79, pp. 77-80, 2010, DOI:10.32604/phyton.2010.79.077

Abstract Asteraceae is one of the largest families of Angiospermae, and contains the Mikania genus. Several species of this family contain polyacetylenic and thiophenic compounds which are used as taxonomic markers. Also, their phototoxic activity acts as plant defense mechanism. In this paper we report the absence of these compounds in Mikania micrantha. We also describe the composition of the volatile oil from the seeds and inflorescence in the species. Linalool and α-pinene were the main components of this M. micrantha’s essential oil. This study tested the ability of extracts of Mikania micrantha to inhibit the mouse ear inflammation in response… More >

Pérez Cuadra V y V Cambi

Phyton-International Journal of Experimental Botany, Vol.79, pp. 69-76, 2010, DOI:10.32604/phyton.2010.79.069

Abstract Pappophorum phillippianum and Trichloris crinita grow in areas where traditional forages cannot establish. They are not food resources for excellence, but have some nutritional value to domestic livestock. Leaves and stems collected in a natural halophytic field were treated using current techniques for describing their epidermic and anatomical characteristics. Blades of both species have papillose adaxial epidermis, and it is also the case for the abaxial epidermis in T. crinita. Silica bodies are double-axe shaped or cross shaped. Both species show foliar glandular and eglandular trichomes. Only T. crinita shows prickles. Anatomically, both species show groups of fibers in the… More >

Gittins¹ C, CA Busso², G Becker¹, L Ghermandi³, G Siffredi¹

Phyton-International Journal of Experimental Botany, Vol.79, pp. 55-68, 2010, DOI:10.32604/phyton.2010.79.055

Abstract Poa ligularis is an important forage in Patagonian rangelands. Populations of this perennial bunchgrass have been severely affected by overgrazing. We propose that increased defoliation frequencies will decrease (1) aerial- and belowground dry matter production, (2) root survival, and (3) concentration and content of total non-structural crown + root carbohydrates, and (4) increase root mortality. Five defoliation frequencies (plus 1 control) were applied in a representative grassland of the Occidental District in Patagonia during two consecutive growing seasons. All four hypotheses were rejected. Aerial and belowground dry matter production increased from one to two or three defoliations. Root production and… More >

López Martínez JD, C Vázquez Vázquez, E Salazar Sosa, R Zúñiga Tarango, HI Trejo Escareño

Phyton-International Journal of Experimental Botany, Vol.79, pp. 47-54, 2010, DOI:10.32604/phyton.2010.79.047

Abstract About 15% of the world surface is subjected to the effect of man activities. The main causes of land surface degradation are livestock production, deforestation and inadequate agricultural practices. In Mexico, little attention has been given to soil conservation as a non-renewable natural resource. This has been mainly degraded by excessive use of agricultural machinery. As a result, 64% of the national territory suffers some degree of deterioration. Comarca Lagunera, located between Coahuila and Durango states in Mexico, is the main milk production region. In this region, 900000 t of cow manure are produced annually. This amount of cow manure… More >

Kandus¹ M, D Almorza³, R Boggio Ronceros², JC Salerno¹

Phyton-International Journal of Experimental Botany, Vol.79, pp. 39-46, 2010, DOI:10.32604/phyton.2010.79.039

Abstract Our objective was to determine the genotype-environment interaction (GxE) in a hybrid integrated by maize lines either carrying or not balanced lethal systems. Experiments were conducted in three locations over a period of two years considering each yearlocation combination as a different environment. Yield data were analysed using the Additive Main Effects and Multiplicative Interaction (AMMI) model and the Sites Regression Analysis (SREG). Results were represented by biplots. The AMMI analysis was the best model for determining the interaction. More >