Paula Kielse

Micropropagação de plântulas de erva-mate obtidas de embriões zigóticos

The aim of this research was to evaluate the micropropagation potential of holly (Ilex paraguariensis Saint Hilaire) aseptic plantlets derived from immature zygotic embryos. Shoot tip were inoculated in a quarter-strength MS basal medium with different doses of 6-benzylaminopurine (BAP) to induce multiple shoots. Shoot tips were inoculated in a basal medium with different doses of indol-butiric acid (IBA) for in vitro rooting and to test their effects in plantlet acclimatization. The addition of 8.88µM BAP to the basal medium increased the number of adventitious shoots and shoot height. Shoot tip rooted in basal medium with 7.38µM IBA in 30 days of culture. The IBA doses of the rooting medium affect plantlet acclimatization. The described micropropagation protocol might be used to produce a high number of holly plants.

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.

Mecanismos de regeneração natural em diferentes ambientes de remanescente de Floresta Ombrófila Mista, São Francisco de Paula, RS

The aim of this study was to evaluate the natural regeneration mechanisms in three floristic groups of the remaining Mixed Rain Forest, located in San Francisco de Paula, RS. The data were collected in six conglomerates of one hectare, subdivided into 16 plots, in which seed rain, soil seed bank, and seedling bank were collected. The groups presented differences in the density of individuals in the seed rain and in

Propagação vegetativa de Cordia trichotoma (Vell.) Arrab. ex Steudel por estaquia radicular

Cordia trichotoma (Vell.) Arrab. ex Steudel is a tree species that has roots with buds and, after the occurrence of natural or anthropic disturbances, sprouts develop from these buds. Considering the natural ability of regeneration by root system, it is assumed that these propagules contain tissues with high morphogenetic potential. The objective of this study was to evaluate the vegetative propagation of C. trichotoma root cuttings. In the first experiment, seedling roots were sectioned into 5.0 cm-long cuttings, classified into thick (1.6-2.5 cm) and thin (1.0-1.5 cm) according to its diameter. The root cuttings were treated in a solution of 0, 10, 20 or 30 mM IBA for 10 seconds. In the second experiment, roots were classified into basal, median and apical according to the position of collection and cut in cuttings with 1.0, 3.0 and 5.0 cm of length. The root cuttings were treated in a solution of 30 mM IBA. The use of IBA favored rooting of root cuttings, with the highest responses in treatments with a dose of 30 mM. Thick root cuttings had a greatest potential for sprouting when compared to thin root cuttings. The highest responses of sprouting and rooting occurred in basal and median root cuttings with 3.0 and 5.0 cm length. In conclusion, it is possible to perform the vegetative propagation of C. trichotoma by the technique of root cuttings.

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.

Estabelecimento e crescimento in vitro de plantas de grápia

The aim of this study was to evaluate the in vitro establishment and growth of apuleia (Apuleia leiocarpa (Vogel) J. F. Macbr.) seedlings under different culture conditions. Apuleia seeds were treated with sulfuric acid (H2SO4) for 20min and disinfected by the immersion in 70% of ethanol for 30s and sodium hypochlorite with 0, 2.5 and 5.0% of active chlorine for 5, 10 and 15min. The percentage of disinfection and germination were evaluated at 30 days. Aseptic seedlings were transferred to WPM, MS and ½ MS culture medium and evaluated for shoot and root (cm) growth and number of nodal segments and leaves at 15 days. Apuleia seeds were also sown in WPM medium supplemented with 4, 5 or 6g L-1 of agar combined with 10, 20 or 30g L-1 of sucrose. The cultures were kept under two luminescence conditions: light throughout the establishment period and dark during the first seven days. The percentage of germination, shoot and root (cm) growth and number of nodal segments and leaves were evaluated at 15 days. In conclusion, the sulfuric acid and ethanol treatments were enough for the in vitro production of apuleia aseptic seedlings. The aseptic seedlings can grow in both WPM and MS medium, supplemented with 10g L-1 of sucrose and 4g L-1 of agar.

Variação nos ganhos de seleção para caracteres de qualidade de tubérculos de batata na região Sul do Brasil

The aim of this study was to evaluate the genetic gain for processing quality of potato tubers in different growing conditions of the southern region of Brazil. Experiments were carried out during summer of Sao Joaquim, Santa Catarina State, and spring and autumn conditions of Julio de Castilhos, Rio Grande do Sul State, representative of the growing conditions of the southern region of Brazil. Eighteen clones were evaluated for chip color and content of dry matter, reduced sugars, starch and amylose. Higher gain from selection was achieved for dry matter and starch content, because of the high inheritance of these traits. There was no correlation among summer, autumn and spring growing conditions for reduced sugars and amylose content; therefore low selection intensity should be applied. Summer growing season maximizes the genetic gain; therefore selection for processing quality should be mainly applied in this environmental condition.

PRODUTIVIDADE DE MICROCEPAS DE GRÁPIA (Apuleia leiocarpa) MANTIDAS IN VITRO

The aim of this work was to evaluate the in vitro productivity of grapia ( Apuleia leiocarpa ) micro-stumps cultivated in different media conditions to maximize its multiplication rate. Micro-stumps from aseptic seedlings were cultivated in WPM medium added with 0, 2.2, 4.4, 6.6 and 8.8 µM of 6-benzylaminopurine (BAP) and subcultured in WPM medium without cytokinin. Micro-stumps were also cultivated in WPM, MS or ½ MS base media with or without the addition of 1.5 g L -1 of activated charcoal and submitted to drastic pruning at 30, 60 and 90 days of cultivation. The in vitro cultivation of grapia micro-stumps in WPM or ½ MS media added with 8.8 µM of BAP and the subcultivation in media without cytokinin increase the number and length of shoots. The cultivation of grapia micro-stumps in media with activated charcoal increases the productivity of micro-cuttings per micro-stumps, but in the absence of activated charcoal induces callus formation and indirect organogenesis of shoots. The in vitro conservation of grapia micro-stumps maximizes the multiplication rate, being a feasible technique for the production of grapia plantlets.