ABSTRACT The objective of the present study was to evaluate the effect of the irrigation water salinity on the initial growth of Tectona grandis plants. The work was carried out in a greenhouse with 100% solar radiation interception at Goiás State University, Ipameri Campus, Brazil. The Tectona grandis seeds were sown in eight-liter pots containing a mixture of soil, sand and manure at ratio 3:1:0.5, respectively. At 100 days after germination, the plants were irrigated daily with water of different electrical conductivity (0, 2, 4, 6, and 8 dS m-1) for 30 days and then subjected to analysis Tectona grandis to stay alive and reduced water loss by transpiration through efficient stomatal control. Tectona grandis plants in the early stages of development are highly sensitive to salinity stress, significantly slowing down vegetative growth.
RESUMO O presente estudo objetivou avaliar o efeito da salinidade da água de irrigação no crescimento inicial de plantas de Tectona grandis. O trabalho foi conduzido em casa de vegetação com interceptação de 100% da radiação solar na Universidade Estadual de Goiás, Campus de Ipameri, Brasil. As sementes de Tectona grandis foram semeadas em vasos de oito litros contendo uma mistura de solo, areia e esterco na proporção de 3:1:0,5, respectivamente. Aos 100 dias após a germinação, as plantas foram irrigadas diariamente com água de diferentes condutividades elétricas (0; 2; 4; 6 e 8 dS m-1) durante 30 dias e, em seguida, submetidas às analises. Para se manterem vivas, as plantas de Tectona grandis reduziram a perda de água por transpiração através de um eficiente controle estomático. As plantas de Tectona grandis na fase inicial de desenvolvimento apresentam elevada sensibilidade ao estresse salino, inclusive com significativa redução do crescimento vegetativo.
Abstract Objective: Composite graft of left internal thoracic artery and great saphenous vein in revascularization of the left coronary system is a technique well described in literature. The aim of this study is to analyze blood flow dynamics in this configuration of composite graft especially in what concerns left internal thoracic artery's adaptability and influence of great saphenous vein segment on left internal thoracic artery's flow. Methods: Revascularization of left coronary system with composite graft, with left internal thoracic artery revascularizing the anterior interventricular artery and a great saphenous vein segment, anastomosed to the left internal thoracic artery, revascularizing another branch of the left coronary system, was performed in 23 patients. Blood flow was evaluated by transit time flowmetry in all segments of the composite graft (left internal thoracic artery proximal segment, left internal thoracic artery distal segment and great saphenous vein segment). Measures were performed in baseline condition and after dobutamine-induced stress, without and with non-traumatic temporary clamping of the distal segments of the composite graft. Results: Pharmacological stress resulted in increase of blood flow values in the analyzed segments (P<0.05). Non-traumatic temporary clamping of great saphenous vein segment did not result in statistically significant changes in the flow of left internal thoracic artery distal segment, both in baseline condition and under pharmacological stress. Similarly, non-traumatic temporary clamping of left internal thoracic artery distal segment did not result in statistically significant changes in great saphenous vein segment flow. Conclusion: Composite grafts with left internal thoracic artery and great saphenous vein for revascularization of left coronary system, resulted in blood flow dynamics with physiological adaptability, both at rest and after pharmacological stress, according to demand. Presence of great saphenous vein segment did not alter physiological blood flow dynamics in distal segment of left internal thoracic artery.