Abstract Detail

Systematics

McMurchie, Elizabeth [1], Clark, Lynn [1].

Does micro match macro? Evaluating patterns of variation in foliar micromorphology in Guadua (Poaceae: Bambusoideae: Bambuseae).

The epidermal micromorphology of foliage leaves is a valuable tool for assessing taxonomic placement of Neotropical woody bamboos. In bamboos with similar macromorphological features, foliage leaf micromorphology can help distinguish different species and reveal potential evolutionary or ecological relationships. Characters such as the shape of silica bodies and the presence, abundance, placement, and shape of stomata and papillae on epidermal cells on different surfaces of the leaf are sometimes diagnostic of certain clades but can show dramatic variation even at the species level. Among the Neotropical woody bamboos, members of the subtribe Guaduinae, including the genus Guadua, are unusual in that most species have numerous stomata on the adaxial surface of the foliage leaf, in addition to the abaxial surface. Most Guadua have also been noted for having papillae associated with these adaxial stomata, although in some species papillae may also be found on long cells of the abaxial surface of foliage leaves. The presence of papillae on both surfaces of foliage leaves has historically been noted in G. paniculata, a widespread species that, unlike most Neotropical woody bamboos, most frequently occurs in open savanna habitats rather than forests or forest margins. Guadua paniculata and other species of Guadua found in open habitats share a suite of macromorphological characteristics, including shorter, narrower culms, culm leaves with subequal sheath and blade, relatively narrow foliage leaves, and shorter pseudospikelets compared to members of the genus found in more forested areas. However, whether patterns of variation in foliar micromorphology in Guadua align with the macromorphological variation based on habitat is not currently known. In this study, we sought to determine whether habitat and geographic location were significant factors in patterns of variation in Guadua foliage leaf epidermal micromorphology. Through a review of scanning electron micrograph (SEM) images of foliage leaves of different species of Guadua, we constructed a multivariate, binary dataset to record the presence or absence of micromorphological character states in individual specimens. To compare the similarity of the specimens, we converted the presence and absence data to distances to visualize the dataspace. Using the simple matching distances, we evaluated a linear model using permutation methods to determine potential causes of variation in foliar micromorphology. Preliminary results indicate that micromorphological patterns differ between species found in open habitats and those found in forested habitats.

1 - Iowa State University, Department Of Ecology, Evolution, And Organismal Biology, 251 Bessey Hall, 2200 Osborn Dr., Ames, IA, 50011, United States

Keywords:
Guadua
Micromorphology
Systematics
Poaceae
Bamboo
Neotropics.

Presentation Type: Oral Paper
Session: SYSTVI, Systematics VI: Monocots to Eurosids I
Location: Virtual/Virtual
Date: Friday, July 23rd, 2021
Time: 10:15 AM(EDT)
Number: SYSTVI002
Abstract ID:689
Candidate for Awards:None