Anatomia quantitativa da folha e do colmo de Brachiaria brizantha (Hochst. ex A. Rich.) Stapf e B. humidicola (Rendle) Schweick

Abstract

Anatomia Quantitativa da Folha e do Colmo deABSTRACT -The forage digestion characteristics can better be understood when associated with studies of tissue anatomy of forage species. Aiming at new focus to this issue, the area of several tissues present in leaves and stems of B. brizantha and B. humidicola, were determined at three different regions of the plant. The assay was carried out at greenhouse, with plants growing in pots with sterilized sand, receiving nutritive solution of macro and micronutrients. After 70 days of growing period, the segment of leaf and stem localized in the center of each of three different insertion planes was collected. The samples were fixed in FAA, embedded in GMA, sectioned in microtome, stained and photographed. The pictures were digitalized and the areas measured with Image Tool software. It was observed that the limbo at bottom plane presents lower area of lignified vascular tissue. On the other hand, at the sheath and stem of B. brizantha, a larger area of parenchymal tissue is found. Compared to B. humidicola, B. brizantha showed greater area of lignified vascular tissue at the limbo, sheath and stem, while the greatest distance among bundle sheath is found at the limbo and sheath, where the number of bundle sheath was higher at the limbo and stem.

<b>Regrowth age modifies the leaf anatomy of <i>Brachiaria</i> genotypes

“…There are many works using that method as a complementary contribution to evaluate the digestibility potential of leaf tissues. Brito, Rodella, and Deschamps (2004) evaluated the anatomy of leaves at different insertion levels in plants of Brachiaria brizantha and B. humidicola and found larger area of lignified tissues related to the lower digestibility of B. brizantha. Bauer, Gomide, Silva, Regazzi, and Chichorro (2008) evaluated the influence of anatomical traits upon the nutritive value of molasses grass (Melinis minutiflora Pal.…”

“…and concluded that lower digestibility coefficients were related to high proportion of xylem and sclerenchyma. In addition, plant anatomy is useful for the comparison of different species, cultivars and the forage maturity (Brito et al, 2004). Furthermore, the decline of nutritive value upon maturity is due to increased lignification (Brito et al, 1999;Paciullo, Gomide, Silva, Queiroz, & Gomide, 2002;Paciullo, 2002;Carvalho & Pires, 2008;Pariz et al, 2010;Medeiros, Pinto, Castro, Rezende, & Lima, 2011;Mauri et al, 2015).…”

Effects of leaf and stem maturation on nutritional value in Megathyrsus maximus

“…However, DMD correlates negatively with NDF, ADF, vascular tissue, and sclerenchyma, as is mentioned in several reports of C4 species. [6][7][8] Brito et al 51 evaluated the anatomy of leaves at different insertion levels in plants of Brachiaria brizantha and Brachiaria humidicola at 70 days growth and found a larger area of lignified tissues related to lower digestibility. Moreover, Batistoti et al 13 showed that a high proportion of fiber was negatively correlated with dry matter digestibility.…”

Sugarcane as a forage plant: Structural and chemical traits that affect fiber quality

“…In this study, the authors found that cv. IACSP95-5000 has a wide range of chemical and structural factors that may be associated with low fiber digestibility (Akin1989; Queiroz et al 2000;Brito et al 2004;Valente et al 2011).…”