Comparative petiole anatomy of cassava (Manihot) species

Abstract

ABSTRACT. In this study, we describe the petiole anatomy of six wild cassava (Manihot) species, one hybrid, and two cultivars of Manihot esculenta, in order to identify their dominant anatomical patterns and relate them to possible adaptations to abiotic factors in the Cerrado biome. The median parts of several petiole samples were transversally and longitudinally sectioned and stained. The results include data for the taxonomic classification of the genus, including distinctive anatomical characteristics of hybrid varieties of cassava and wild species, such as the presence/ absence of trichomes and a hypodermis, layer type and number in the cortex, number of vascular bundles, cell types in the pith, and type of organization. Morphological analysis revealed differences in length and shape of the petiole insertion. The presence of trichomes, a hypodermis, the amount and type of supporting tissue in the cortex, as well as gelatinous fibers, may be related to drought tolerance.

Comparative leaf anatomy of wild Manihot Mill. species (Euphorbiaceae) from Chapada Diamantina, Bahia, Brazil

“…In the analyzed species, articulated anastomosing laticifers were observed in all regions of the leaf blade and petiole, especially in the subepidermal region, or associated with phloem in vascular bundles. The occurrence of laticifers in Manihot has also been reported by Vannucci (), Allem (), Mendonça (, 1992), Cunha Neto et al (), Graciano‐Ribeiro et al () and Silva et al ().…”

“…It is important to emphasize that different numbers of vascular bundles have been reported for the same species (e.g. M. cecropiaefolia , Cunha Neto et al ) as in M. caerulescens in which we found seven while Graciano‐Ribeiro et al () found eight, and more examples might come to light as additional species are studied. As indicated in other groups, this problem might be related to the fact that the number and arrangement of vascular bundles in the petiole in eudicotyledons can vary in different regions of the leaf (Rocha and Neves , Souza et al ).…”

Morphological and anatomical evidence support a new wild cassava: Manihot fallax (Crotonoideae, Euphorbiaceae), from Mato Grosso, Brazil

“…Amongst the anatomical features that differ between M. fallax and M. attenuata , the presence the fibres in the vascular cylinder in the midvein, the papillae in the epidermal cells and the arrangement and number of collateral bundles in the petiole have been cited by Allem (1984), Cunha Neto et al (2014) and Graciano-Ribeiro et al (2016) as characters that help differentiate species in Manihot .…”

“…The leaf anatomy of the new species and the species most morphologicaly similar to it were also compared because leaf anatomy constitutes an important tool for delimiting taxa in Manihot (e.g. Vannucci 1982, Cunha Neto et al 2014, Cunha Neto et al 2017 and Graciano-Ribeiro et al 2016). Additionally, as part of these studies on Manihot of the Cerrado flora, M. robusta as a synonym of M. attenuata Müll.…”

Anatomy and histochemistry ofManihot caerulescensPohl (Euphorbiaceae) Leaf anatomy ofManihot caerulescens

“…In this sense, it is worth highlighting the studies of Milanez 1952;Milanez & Monteiro Neto 1956;Mahlberg 1959;Mahlberg & Sabharwal 1968;Fineran 1983;Mahlberg 1975;Rudall 1987;Castro & Demarco 2008;Demarco et al 2013. Studies with Manihot laticifers were developed by Vannucci (1982), Mendonc ßa (1983, 1992), Cunha Neto et al (2014, Graciano-Ribeiro et al (2016) and Silva et al (2016).…”