Comparative wood anatomy of root and stem of Citharexylum myrianthum (Verbenaceae)

Abstract

Root and stem wood anatomy of C. myrianthum (Verbenaceae) from a semideciduous seasonal forest in Botucatu municipality (22º52'20"S and 48º26'37"W), São Paulo state, Brazil, were studied. Growth increments demarcated by semi-ring porosity and marginal bands of axial parenchyma were observed in the wood of both root and stem. Many qualitative features were the same in both root and stem: fine helical thickenings, and simple and multiple perforation plates in vessel elements; large quantities of axial parenchyma in the growth rings, grading from marginal bands and confluent forming irregular bands in earlywood to lozenge aliform in latewood; axial parenchyma cells forked, and varied wall projections and undulations; septate fibres; forked and diverse fibre endings. Quantitative features differing between root and stem wood were evaluated using student's t-test, and vessel frequency, vessel element length, vessel diameter, ray height, and vulnerability and mesomorphy indices differed significantly. Root wood had lower frequency of vessels, narrower and longer vessel elements, and taller rays than wood of the stem. The calculated vulnerability and mesomorphy indices indicated that C. myrianthum plants are mesomorphic. Roots seem to be more susceptible to water stress than the stem. ResumoA anatomia da madeira da raiz e do caule de Citharexylum myrianthum (Verbenaceae) que ocorre em uma área de floresta estacional semidecídua próximo à cidade de Botucatu (22º52'20"S e 48º26'37"W), estado de São Paulo, Brasil, foi estudada. Camadas de crescimento distintas, demarcadas por anel semi-poroso e faixas marginais de parênquima axial foram observadas em ambos os órgãos. As características qualitativas observadas tanto em raiz quanto em caule foram: espessamentos helicoidais finos e placas de perfuração simples e múltiplas em elementos de vaso; grandes quantidades de parênquima axial nos anéis de crescimento, em faixas marginais a confluente formando faixas irregulares no lenho inicial a aliforme losangular no lenho tardio; células do parênquima axial bifurcadas, com projeções e ondulações na parede; fibras septadas; fibras bifurcadas e com diversas terminações. Na análise quantitativa comparativa entre raiz e caule foi aplicado teste t-student que mostrou diferenças significativas na frequência e diâmetro de vasos; comprimento dos elementos de vaso; altura dos raios; índices de vulnerabilidade e mesomorfia. A madeira da raiz teve menor frequência de vasos, vasos com menor diâmetro e elementos mais longos, e raios mais altos. Os índices de vulnerabilidade e mesomorfia indicaram que as plantas de C. myrianthum são mesomórficas. As raízes parecem estar mais susceptíveis ao estresse hídrico do que os caules. Palavras-chave: anatomia da madeira, floresta estacional semidecídua, xilema secundário. Comparative wood anatomy of root and stem of Citharexylum myrianthum (Verbenaceae)Anatomia comparada da madeira de raiz e caule em Citharexylum myrianthum (Verbenaceae)

Structural differences in the secondary phloem suggest higher support and storage potential in stems than roots ofCytharexylum myrianthumCham. (Verbenaceae)

“…In addition, we noticed similar ray cellular composition in both the secondary phloem described here and the secondary xylem previously described by Marcati et al (2014). This likely reflects their common origin from the same meristem, the vascular cambium (Esau 1979).…”

“…Wider vessels of the earlywood are formed during the period of higher water availability, while narrower ones are formed during the dry period (Wheeler and Baas 1991;Carlquist 2001). In the secondary phloem, the formation of growth rings would be equivalent to the formation of semi-ring porous wood described for this species (Callado et al 2001;Marcati et al 2014). Likewise, the wider diameter of the sieve-tube elements in the secondary phloem formed at the onset of the growing season would derive from the higher water availability in the favorable period, which allows higher turgor pressure for the expansion of the new cells (Abe et al 2003;Woodruff 2014).…”

“…The growth rings of the secondary phloem in C. myrianthum stems and roots are characterized by a region of wider sieve elements and a region of narrower sieve D r a f t elements (described in detail in Angyalossy et al 2006). In the secondary xylem of this species, semi-ring porous wood is formed, characterized by wider vessels in the earlywood and narrower vessels in the latewood (Callado et al 2001;Marcati et al 2014). Wider vessels of the earlywood are formed during the period of higher water availability, while narrower ones are formed during the dry period (Wheeler and Baas 1991;Carlquist 2001).…”

Performance of Five Native Atlantic Forest Species Planted in Containers of Different Size for Restoring Degraded Areas in Minas Gerais

“…Taking into account the dry winter conditions of Viçosa, the area of the Zero Carbon Program undergoes periods of drought (June to September), which could have contributed to the low SV of this species [18]. Citharexylum myrianthum does not have the same degree of specialization for water deficits between the trunk and roots, with the roots being more sensitive to drought than the trunk; i.e., this species does not tolerate water deficit conditions, requiring silvicultural treatments, such as those related to the irrigation [25]. The low adaptability of C. myrianthum has been corroborated in nearby areas at the site of study [16,26,27].…”

The anatomical structure of the root, stem, and branch of Gyrinops versteegii trees from different growing sites

“…Moreover, the anatomical structure differences in various parts must be studied to understand the wood characteristics, function, and physiological interaction between the trees (Fortunel et al 2014;Marcati et al 2014;Longui et al 2017). Therefore, this study aims to investigate the anatomical structure of G. versteegii agarwood species on the root, stem, and branch parts from two different sites on Java Island, namely Pacitan and Klaten Districts.…”