RELATIONSHIP BETWEEN LIGNIN CONTENT AND QUALITY OF Pinus taeda SEEDLINGS1

Abstract

-The essay objective was to correlate lignin content resulting from tigmomorphogenesis induced by stem swaying with survival and post-planting growth of P. taeda seedlings. Seedlings were subjected to daily frequencies (0, 5, 10, 20 and 40 movements) of stem swaying for 60 days. By the end of the treatments, we determined lignin content of below and aboveground seedling tissues. Four replicates per treatment were planted in a area cultivated with pines. Ninety days after planting, survival and increments of seedling height, stem diameter and stem volume were quantified. Application of 20 stem swayings increased lignin in both below and aboveground plant tissues. Outplanted seedling survival was reduced with 40 stem swayings while growth increments were increased with both 10 and 20 stem swayings. Lignin content from belowground plant tissues was positively correlated with outplanted seedling survival while lignin from aboveground tissues correlated with height and stem volume increments. P. taeda seedlings with higher lignin content have higher survival chances after planting.Keywords: Thigmomorphogenesis; Hardening; Stem swaying. RELAÇÃO ENTRE TEOR DE LIGNINA E QUALIDADE DE MUDAS DE Pinus taedaRESUMO -O ensaio objetivou correlacionar o teor de lignina resultante da tigmomorfogênese induzida por flexões caulinares com a sobrevivência e o crescimento pós-plantio em mudas de P. taeda. As mudas foram submetidas a cinco frequências de flexões caulinares diárias (0, 5, 10, 20 e 40 flexões) com o auxilio de um aparato mecânico por 60 dias. Ao final, determinou-se o teor de lignina nos tecidos radiculares e aéreos. Quatro repetições por tratamento foram plantadas em uma área de monocultivo de Pinus. Noventa dias após o plantio, quantificou-se as taxas de sobrevivência e de crescimento inicial em altura, em diâmetro do coleto, e volume do caule. A aplicação da frequência de 20 flexões induziu a um aumento no teor de lignina nos tecidos radiculares e aéreos. A campo, a sobrevivência das mudas foi reduzida com o tratamento de 40 flexões, enquanto as taxas de crescimento foram aumentadas com a aplicação de 10 ou 20 flexões. O teor de lignina nos tecidos radiculares correlacionou-se positivamente com a sobrevivência a campo da mudas, enquanto o teor nos tecidos aéreos correlacionou-se com os incrementos em altura e no volume do caule. Mudas de P. taeda com maior teor de lignina apresentam maiores chances de sobrevivência pós-plantio.Palavras-chave: Tigmomorfogênese; Rustificação; Flexão caulinar.

Shade stress decreases stem strength of soybean through restraining lignin biosynthesis

“…* and ** indicate significant at the 0.05 and 0.01probability levels, respectively. regarded as macromolecule, which played a supportive and constitutive role in improving mechanical strength of stem, enhancing stem stiffness, providing stem rigidity and eventually reducing the lodging by maintaining the verticality of stem (Vance et al 1980;Lewis and Yamamoto 1990;Xu et al 2009;Wang et al 2014;Dranski et al 2015). In the present study, the data demonstrated that the lignin accumulation of soybean stem was positively correlated to the stem stress (breaking strength per cross section), suggested that high lignin in soybean stem increased the physical strength of stem.…”

Production of Bertholletia excelsa Humb. & Bonpl., (Lecythidaceae) seedlings in microenvironments under different substrates

“…Physical stimuli applied as stem flexion makes seedlings to trigger morphometric responses normally associated to height reduction, increase in the stem collar diameter, and increase in the dry mass of the root tissue (Volkweis et al, 2014;Dranski et al, 2015). Such response to physical stimuli is defined as thigmomorphogenesis (Jaffe, 1973), which is observed in phases where seedlings are getting more resistant to mechanical injuries.…”

“…Such response to physical stimuli is defined as thigmomorphogenesis (Jaffe, 1973), which is observed in phases where seedlings are getting more resistant to mechanical injuries. Therefore, it is possible to imply that there is a relation between seedlings tissues lignification and their growth and survival performance in the field (Dranski et al, 2015).…”

Photosynthetic responses of <i>Eucalyptus seedlings</i> submitted to chemical and mechanical stimulus

“…Several authors indicated that some practices such as mechanical stimuli and plant growth regulators may be related to improvements of seedling quality from woody species (JACOBS;LANDIS, 2009;ORO et al, 2011;VOLKWEIS et al, 2014;CADORIN et al, 2015;DRANSKI;MALAVASI;MALAVASI, 2015). Thus, such practices could be included in nursery routine, favoring development after planting.…”

“…Current reactions to a significant number of woody species have been reported. Among them are cellular stretching reductions, with consequent reduction in the height of the seedlings and the increase in stem diameter, indicators of seedling quality (KERN et al, 2005;VOLKWEIS et al, 2014;CADORIN et al, 2015;DRANSKI;MALAVASI;MALAVASI, 2015).…”