Elci Terezinha Henz Franco

TRATAMENTOS PRÉ-GERMINATIVOS EM SEMENTES DE Didymopanax morototoni (Aubl.) Dcne. et Planch

Didymopanax morototoni (Aubl.) Dcne. et Planch, (caixeta), is a native forest tree with economical importance in Brazil. It has a large natural distribution, with rapid growth and is a pioneer species. But the seeds of that species have a low rate of germination. The aim of this work was to evaluate the effect of the pre-treatments on the germination capacity. The following treatments were tested: immersion of seed in water for 8 h; chemical scarification with HCl and H 2 SO 4 a 70%; washing with water and alcohol + water (1:1) at different times (15, 30 and 45 min.) and mechanical scarification. In vitro germination tests were also carried out. Seeds without test were inoculated in the WPM medium solidified with agar (6 g/l) in presence of kinetin and gibberelic acid on the concentration of 0; 0,1; 0,5; 1,0 mg/l, plus hydrolysed casein on the concentration of 250 mg/l. The incubation was at de 25 ±1°C, in germination chambers under photoperiod of 16 hours light under14, 3 μE.m-². s-¹ or in the darkness. The germination was improved by the pre-treatments rinsed in water or water plus alcohol in 45 minutes. The addition of kinetin and gibberelic acid allowed an improvement in the germination of 40 to 70%. The results confirmed that there was a partial dormancy due to teguments and point out to possible presence of inhibitory substances in them which can be removed by washing the seeds.

Regeneração in vitro de Parapiptadenia rigida

The aim of this research is to develop a micropropagation protocol for Parapiptadenia rigida using aseptic seedling explants from in vitro germinated seeds. To the sprout induction, cotyledonary and nodal segments were inoculated in a ½ WPM culture medium containing 0; 0.25; 0.50; 1.0mg L-1 of BAP or KIN. The rooting of sprouted explants was rooted in a ¼ WPM culture medium containing 0; 0.25; 1.0; 1.75mg L-1 of IBA. It was not necessary the addition of cytokinin in medium to induce sprouting in cotyledonary and nodal segments. However, the doses of 0.50mg L-1, independently of cytokinin type, promoted greater size of sprouts and the largest number of leaves per sprout. The highest rooting potential occurred in cotyledonary segments inoculated in medium with 1.0mg L-1 of IBA. The use of this regeneration protocol allows obtaining Parapiptadenia rigida seedlings.

Substratos e estacas com e sem folhas no enraizamento de Luehea divaricata Mart.

An experiment was carried out to evaluate the influence of substrate and type of stem cuttings on the rooting of Luehea divaricata. The experiment was conducted at a Forest Seedbed at the Federal University of Santa Maria (UFSM), from December 2006 to February 2007. Herbaceous stem cuttings were used (with and without leaf), of plant matrices of approximately two years of age distributed as substrate (peat, Plantmax®, vermiculite, Mecplant ®) in factorial 2 x 4. The experimental design was completely randomized and consisted of bifactorial combination with five units per repetition and 10 repetitions per treatment. The evaluations have been performed 60 days after the implantation of the experiment. The variables observed were: survival, rooting, number of roots, length of roots and dry mass of the roots and of the aerial part. The type of stem cuttings presented influence for the variables analyzed, considering that 100% of the stem cuttings without leaf died before rooting. Stem cuttings cultivated in Plantmax® showed higher length of the roots than Mecplant®. The use of peat and Plantmax® substrate enabled more values for the dry mass of leaf and roots. Stem cuttings with a pair of leaf grown in Plantmax ® are indicated in the vegetative propagation of Luehea divaricata.

Enraizamento de estacas de Sebastiania schottiana Müll. Arg.

The aim of this study was to verify the rooting potential of Sebastiania schottiana cuttings treated with different doses and immersion times in Orgasol® FTS (composed with amino acids and micronutrients). In a first trial, basal, median and apical cuttings had their bases immersed in Orgasol® FTS at levels of 0, 5, 10 and 15mL L-1, for 1 minute. The experimental design was in random blocks, with three replicates and 20 cuttings per plot. At 75 days, the rooted cuttings percentage, the length and diameter of the longest root were evaluated. In a second trial, basal and median cuttings were treated for 0, 15, 30 and 45 minutes in 15mL L-1 of Orgasol® FTS. The experimental design was in random blocks, with three replicates of 20 cuttings per plot. At 150 day, the rooted cuttings percentage, dry roots mass and the length and diameter of the longest root were evaluated. In the first trial, higher levels of product was beneficial to rooting, it was observed the largets rooted cuttings percentage in the treatment with 15mL L-1 of product. In second trial, the higher rooting potential was observed in the basal and median cuttings treated by 45 minutes in 15mL L-1 of product. The use of orgasol® FTS promotes adventitious roots in Sebastiania schottiana cuttings.

QUEBRA DE DORMÊNCIA DE SEMENTES DE ESPINILHO (ACACIA CAVEN Mol..)

SUMMARY Seeds of Espinilho (Acacia caven Mol.) were submitted to different methods of breaking seed dormancy. The treatments were: sulfuric acid; ethanol (95% vol) and boiling water with different imersion periods; seed escarification using sandpaper and the control (intact seeds). The most effective treatments were sulfuric acid for two hours and seed escarification.

Ácido indolbutírico em diferentes diâmetros na estaquia de Luehea divaricata

Luehea divaricata Mart. is a medium-sized-tree of a resistent wood and great flexibility, characteristics which qualify it as raw material in the manufacture of furniture. Due to the relevance of this species to the forest based industry the project was conducted in order to investigate the indolbutyric acid and the diameter of the stem cuttings as a subsidy for the production of matrices adequate for comercial use. Stem cuttings of 20cm of length taken from matrices of approximately ten years of age were used. The treatments consisted of the combination between stem cuttings of three classes of diameter: fine (0.4-0.8cm), medium (0.9-1.4cm) and thick (1.5-2.6cm) and two levels of solution IBA (0, 5000mg L-1). A completely randomized experimental design was used and consisted of bifactorial combinations with 12 units per repetition and five repetitions per treatment. 90 days after the implantation of the experiment the following variables were evaluated: survival, rooting, number and length of the roots. Thick and medium stem cuttings immersed in 5000mg L-1 of hidroalcolic solution of IBA are indicated in the vegetative propagation of Luehea divaricata.

Crescimento inicial do guatambú, Balfourodendron riedelianum (Engl.) Engel. em diferentes intensidades luminosas.

In the nursery at the Department of Science Foresty, of the UFSM, during 8 months, was analysed the behaviour of the seedlings of Balfouodendron riedelianum (Engl.) Engl., in different degrees of luminosity, in the initial growth stage. Blocks with four repetitions and with four levels of luminosity (30, 50, 70 and 100%) were used (at random) as an experimental delineation. The height and neck diameters were take for each 30 (thirty) days period, totaling 5 (five) evaluations, obtaining a final result statistically superior in 30% and 79,59% of luminosity respectively. The total fesh mass, of air part and radicular was obtained with 76,21% 69,98% and 78,75% of luminosity, respectively. The maximun production of drought matter of seedlings was obtained with 67,56% of luminosity, the larger root/aerial part relation with 78,35% and the best radicular prolongation with 76,16% of luminosity, In all of the evaluated parameters, the treatment where the seedlings were exposed to the total light showed a deficient development, with a high rate of mortality. The Balfourodendron riedelianum (Engl.) Engl., according to the aspects seen above, appears to be a specie withfisiologic plasticity.

EFEITOS DA INTERAÇÃO DE AUXINAS E SISTEMAS DE CULTIVO IN VITRO NA INDUÇÃO DE CALOS A PARTIR DE EMBRIÕES DE ARROZ

SUMMARY A medium for calius development was studied for growing mature embryos of rice (Oryza sativa L), variety BR-IRGA 414, in medium MS with different concentration of synthetic auxins, NAA and 2.4-D (0.5; 1.0; 5.0 e 10.0mg/l). Each concentration had additional treatments including presence and absence of cinetin (0.2mg/l) and of light (cold-white bulb, 4000 lux intensity). The experimental design was completely randomized with three factor and tive replications. The addition of auxins was effective in calius formation but with NAA was not observed positive effects of cinetin and light on calius weight. However, where cinetin was added in dark condition calius weight increased 358%. With 2.4-D, calius weight decreased in presence of light and cinetin.

OBTENÇÃO in vitro DE BROTOS DE Begonia rieger COM THIDIAZURON, CINETINA E ÁCIDO NAFTALENO ACÉTICO

Petiole segments, basal and distal leaf disks were cultivated in MS medium to determine an adequate protocol to obtain shoots of Begonia rieger. The MS medium was used with four combinations of naphthaleneacetic acid (NAA) and kinetin, respectively: 0.01 + 0.1; 0.05 + 0.5; 0.1 + 1.0; 0.2 + 2.0mg/l, and in two combinations of NAA and thidiazuron (TDZ), respectively: 0.01 + 0.1 and 0.01 + 0.25mg/l. Basal leaf disks were more effective to form shoots (60 to 80%) without roots. However petiole segments were more effective to form rooted shoots. The concentration of 0.1 mg/l of NAA plus 1.0mg/l of Kinetin was more effective to form shoots from distal leaf disks. The TDZ at smaller concentration was more effective to form shoots without roots (60%). It induced more shoots than kinetin. The distal leaf disks produced more shoots with 0.1 mg/l of NAA and 1.0mg/l of kinetin. The smaller concentration of TDZ induced more shoots, 80 and 90%, respectively, for distal and basal leaf disks. For petiole segments the highest TDZ concentration induced more shoots. In both TDZ concentrations the explants remained in active vegetative growth, oposed as observed for kinetin.