Physiological Characteristics Of Eucalyptus spp Seedlings Submitted To Saline Stress

The objective of this study was to evaluate the effects of increasing sodium chloride (NaCl) concentrations on quantum potential efficiency of the photosystem II (Fv/Fm), index of the intensity of the green color in leaves (SPAD value), dry leaf biomass, leaf area and potassium (K) and sodium (Na) concentrations in Eucalyptus seedlings leaves. The experiment was carried out in a green house, using 11.5 L pots filled with sand and irrigated with nutrient solution, in Campos dos Goytacazes (RJ). The experiment was set up according to a completely randomized factorial design, with four species ( Eucalyptus camaldulensis , Eucalyptus tereticornis , Eucalyptus pellita and Eucalyptus robusta ) and five saline levels (1.41; 2.50; 4.50; 6.45 and 8.33 dS m-1), with five replicates. Up to the maximum applied saline level, seedlings of Eucalyptus camaldulensis , Eucalyptus tereticornis and Eucalyptus robusta showed positive responses regarding SPAD values and quantum potential efficiency of the photosystem II, dry leaf biomass and leaf area. These evaluations suggest tolerance of these species to saline conditions. Seedlings of Eucalyptus pellita showed sensitivity to saline stress. The reductions of dry leaf biomass and leaf area may be related to seedling resistance to saline conditions.Este trabalho objetivou avaliar como o aumento da concentra\ue7\ue3o de cloreto de s\uf3dio (NaCl) influencia o rendimento qu\ue2ntico potencial do fotossistema II (Fv/Fm), \uedndice da intensidade da cor verde nas folhas (valor SPAD), \ue1rea foliar, biomassa seca foliar e concentra\ue7\ue3o de pot\ue1ssio (K) e s\uf3dio (Na) nas folhas de mudas de esp\ue9cies de Eucalyptus. O experimento foi conduzido em casa de vegeta\ue7\ue3o, em vasos de 11,5 L, preenchidos com areia e irrigados com solu\ue7\ue3o salinizada, em Campos dos Goytacazes, RJ. O delineamento experimental foi inteiramente casualizado em esquema fatorial com quatro esp\ue9cies ( Eucalyptus camaldulensis , Eucalyptus tereticornis , Eucalyptus pellita e Eucalyptus robusta ) e cinco n\uedveis de salinidade (1,4; 2,50; 4,50; 6,45 e 8,33 dS m-1), com cinco repeti\ue7\uf5es. At\ue9 o n\uedvel m\ue1ximo de salinidade aplicado, as mudas de Eucalyptus camaldulensis , Eucalyptus tereticornis e Eucalyptus robusta responderam positivamente com rela\ue7\ue3o \ue0s caracter\uedsticas valor SPAD, rendimento qu\ue2ntico potencial do fotossistema II, biomassa seca foliar e \ue1rea foliar. Essas avalia\ue7\uf5es sugerem toler\ue2ncia dessas esp\ue9cies \ue0s condi\ue7\uf5es de salinidade impostas. Mudas de Eucalyptus pellita mostraram sensibilidade ao estresse salino. As redu\ue7\uf5es da biomassa seca e \ue1rea foliar podem estar relacionadas a estrat\ue9gias de resist\ueancia das plantas ao estresse salino

MORFOLOGIA DE FRUTOS E SEMENTES E GERMINA\uc7\uc3O DE Poincianella pyramidalis (Tul.) L. P. Queiroz, comb. Nov

O objetivo deste trabalho foi descrever os caracteres morfol\uf3gicos dos frutos, sementes e pl\ue2ntulas, caracterizar o processo de germina\ue7\ue3o e verificar se a posi\ue7\ue3o da semente no fruto interfere na germina\ue7\ue3o de sementes de Poincianella pyramidalis. Os frutos foram coletados de cinco \ue1rvores-matrizes em propriedade rural situada no munic\uedpio de Castro Alves - BA - Brasil em \ue1rea pr\uf3xima a remanescentes de Caatinga sensu stricto e Floresta Estacional. O fruto de Poincianella pyramidalis \ue9 do tipo legume, polisp\ue9rmico, deiscente, medindo, em m\ue9dia, 9,4\ub10,08 cm de comprimento, podendo conter at\ue9 8 sementes por fruto, sendo o n\ufamero m\ue9dio de sementes, aparentemente vi\ue1veis, por 100 frutos de 280\ub129,8. A semente \ue9 elipsoide de cor castanho-amarelada e superf\uedcie lisa, polida e dura, sendo provida de testa e tegma, com comprimento de 1,25 \ub1 0,004 cm. O embri\ue3o \ue9 axial, invaginado e reto e n\ue3o foi verificada presen\ue7a de endosperma. O peso de 1000 sementes foi de 106,8 \ub1 12,4 g. A germina\ue7\ue3o \ue9 ep\uedgea fanerocotiledonar, teve in\uedcio no terceiro dia ap\uf3s a semeadura e a forma\ue7\ue3o completa da pl\ue2ntula foi verificada no nono dia. A produ\ue7\ue3o de sementes de Poincianella pyramidalis na posi\ue7\ue3o proximal \ue9 inferior em rela\ue7\ue3o \ue0s demais posi\ue7\uf5es. O percentual de germina\ue7\ue3o \ue9 influenciado pela posi\ue7\ue3o da semente no fruto, sementes na posi\ue7\ue3o distal apresentam germina\ue7\ue3o inferior \ue0s sementes das demais posi\ue7\uf5es.The objective of this study was to describe the morphological characters of fruits, seeds and seedlings, characterize the germination process and verify that the seed position in the fruit interferes with the seed germination of Poincianella pyramidalis. The fruits were collected from five trees in the Castro Alves, Bahia \u2013 Brazil in the area near the remnants of Caatinga sensu stricto and Deciduous Forest. The fruit of Poincianella pyramidalis is a type of legume, polyspermic, dehiscent, measuring on average 9.4 \ub1 0.08 cm in length and can contain up to 8 seeds per fruit, being the average number of seeds, apparently viable fruits per 100 \ub1 280 29.8. The seed is ellipsoid, yellowish brown color and smooth, polished and hard, being provided testa and internal tegument, with a length of 1.25 \ub1 0.004 cm. The embryo is axis, invaginated and straight and there was no presence of endosperm. The weight of 1000 seeds was 106.8 \ub1 12.4 g. Germination is phanecotylar-epigious began the third day after sowing and the complete formation of the seedling was observed on the ninth day. Seed production of Poincianella pyramidalis in the proximal position is lower compared to other positions. Seed germination is influenced by seed position in the fruit, seeds present in the distal lower seed germination of other positions