Acclimatization of Musa spp. seedlings using endophytic Bacillus spp. and Buttiauxella agrestis strains.

The association of different species of endophytic bacteria with the rhizosphere of the host plants can stimulate growth, development and acclimatization, offering a greater quantity of seedlings, in addition to reducing the cycle, providing economic return to the producer. The objective of this study was to evaluate the effect of introduction four bacterial isolates through inoculation into the root system in three banana cultivars (Prata Anã, Grande Naine and BRS Princesa) in the acclimatization phase. The evaluated treatments were: control (nutrient broth without bacteria); Bacillus cereus strain 1 (BC1); Bacillus cereus strain 2 (BC2); Bacillus thuringiensis (BT); Buttiauxella agrestis (BA). The morphological characteristics related to the development of the plants (total height and pseudostem diameter) were evaluated throughout the acclimatization period. After 90 days of transplanting and acclimatization, root length, leaf number, dry root weight, pseudostem and leaf, leaf area, internal carbon concentration, stomatal conductance, photosynthesis rate, transpiration rate, leaf temperature and chlorophyll were evaluated. The bacteria showed different results in relation to the studied cultivars. Considering the morphological and physiological characteristics observed in this study, B. thuringiensis for the cultivars Prata Anã and Grande Naine and the B. agrestis for the cultivar BRS Princesa are recommended for the process of acclimatization of banana seedlings, as they stimulated growth of the plant, increasing the dry mass, besides promoting the growth of roots. In this way, they improved the physiological aspects of the plants and reduced the period of acclimatization of the banana.

Multiplicação in vitro de copo-de-leite: espectros de luz e sacarose / Calla lily in vitro multiplication: spectrum of light and sucrose

O espectro luminoso pode alterar a morfogênese das plantas por meio de uma série de processos mediados por receptores de luz, principalmente na região do vermelho e azul. O objetivo deste trabalho foi determinar um possível tipo de luz mais ativo que a luz branca, de forma a aumentar a eficiência da multiplicação in vitro de copo-de-leite e obter um nível ótimo de sacarose. Para isso, os tratamentos consistiram em quatro diferentes tipos de luz, sob os quais os explantes cresceram (branca, vermelha, azul e verde), fornecidos pelo espectro luminoso das lâmpadas fluorescentes coloridas T8 20W Ecolume 05/1 e sacarose (0; 15; 30; 45 e 60g L-1). O meio de cultura constituiu-se dos sais e das vitaminas de MS, adicionado de 5mg L-1 de BAP e 5,5g L-1 de ágar. O tipo de luz não influencia a multiplicação in vitro de copo-de-leite, e o maior número de brotos (2,0) é obtido em 45g L-1 de sacarose. Observou-se maior número de folhas em luz branca (3,8) e azul (2,9), com 15 e 60g L-1 de sacarose, respectivamente. Maior comprimento dos brotos (3,7cm) foi observado em 60g L-1 de sacarose, e maior fitomassa fresca da parte aérea (1,07g) foi observada com a utilização de 60g L-1 de sacarose.

Light spectrum can modify plant morphogenesis through a number of processes mediated by light receptors, mainly in the red and blue region. The aim of this work was to determine a possible light type more active than the white light, and an optimized sucrose concentration, in order to increase the efficiency of the calla lily in vitro multiplication . To that end, the treatments consisted of four different light types (white, red, blue and green), under which the explants grew, supplied by colored T8 20W Ecolume 05/1 fluorescent lamps and various sucrose concentrations (0; 15; 30; 45 and 60g L-1). The culture medium contained MS salts and vitamins, added of 5mg L-1 BAP and 5.5g L-1 agar. The light type did not influence in vitro propagation of calla lily and there were a higher number of sprouts (2.0) in 45g L-1 of sucrose. There was higher number of leaves in white (3.8) and in blue light (2.9) with 15 and 60g L-1 of sucrose, respectively. Higher length of sprouts (3.7cm) was observed in 60g L-1 of sucrose and higher fresh weight of the aerial part (1.07g) in 60g L-1 of sucrose.

Fontes de potássio no crescimento in vitro de plantas de orquídea Cattleya loddigesii / Potassium sources of Cattleya loddigesii plants in vitro growth

Plantas de Cattleya loddigesii com 1,0-1,5cm de comprimento, oriundas de sementes germinadas in vitro, foram inoculadas nos tratamentos, os quais consistiram da adição de diferentes concentrações de cloreto e sulfato de potássio (ambos a 0, 125, 250, 375 e 500mg L-1) ao meio Knudson C, em todas as combinações possíveis, acrescido de 2g L-1 de carvão ativado e 150g L-1 de polpa de banana "Nanica". O meio teve seu pH ajustado para 5,8±0,1 e foi solidificado com 5g L-1 de ágar antes da autoclavagem a 121°C por 20 minutos. Após a inoculação, as culturas foram mantidas por 90 dias em sala de crescimento com irradiância em torno de 35µmol m-2 s-1, temperatura de 25±1°C e fotoperíodo de 16 horas. A combinação de 500mg L-1 de KCl com 500mg L-1 de K2SO4 promoveu maior crescimento in vitro em plantas de Cattleya loddigesii, exceto no comprimento de raízes, que se apresentou melhor com 500mg L-1 de KCl na ausência de K2SO4.

Cattleya loddigesii preceding seedlings (with 1.0-1.5cm) of in vitro germinated seeds were used as explants. The treatments consisted of the addition of different potassium chloride concentrations (0; 125; 250; 375 e 500mg L-1) and potassium sulphate (0; 125; 250; 375 e 500mg L-1), in the Knudson C medium, in all possible combinations, an addition of 2g L-1 activated coal, 150g L-1 and banana 'Nanica' pulp. The medium had the pH set to 5.8±0.1 and was solidified with agar 5g L-1 before the sterilization at 121°C for 20 minutes. After the inoculation, the cultures were maintained in the growth room with irradiancy around 35µmol m-2 s-1 in, 25±1°C temperature and 16-hour photoperiod for 90 days. The combination of KCl 500mg L-1 with K2SO4 500mg L-1 promotes good in vitro growth in Cattleya loddigesii seedlings, except length of roots who if comported better with KCl500 mg L-1 in absence of K2SO4.