Variation within laminae: Semi‐automated methods for quantifying leaf venation using phenoVein

Abstract

PREMISE: Physiological processes may vary within leaf laminae; however, the accompanying heterogeneity in leaf venation is rarely investigated because its quantification can be time consuming. Here we introduce accelerated protocols using existing software to increase sample throughput and ask whether laminae venation varies among three crop types and four subspecies of Brassica rapa. METHODS: FAA (formaldehyde, glacial acetic acid, and ethanol)-fixed samples were stored in ethanol. Without performing any additional clearing or staining, we tested two methods of image acquisition at three locations along the proximal-distal axis of the laminae and estimated the patterns of venation using the program phenoVein. We developed and made available an R script to handle the phenoVein output and then analyzed our data using linear mixed-effects models. RESULTS:Beyond fixation and storage, staining and clearing are not necessary to estimate leaf venation using phenoVein if the images are acquired using a stereomicroscope. All estimates of venation required some manual adjustment. We found a significant effect of location within the laminae for all aspects of venation. DISCUSSION: By removing the clearing and staining steps and utilizing the semi-automated program phenoVein, we quickly and cheaply acquired leaf venation data. Venation may be an important target for crop breeding efforts, particularly if intralaminar variation correlates with variation in physiological processes, which remains an open question. KEY WORDS areole area; Brassica rapa; leaf venation; phenoVein; venation density, venation variation. Applications in Plant Sciences 2020 8(5): e11346 Newsome et al.-Quantifying variation in leaf venation using phenoVein • 2 of 7

Teasing out elevational trends in infraspecific Prunus taxa: A vein analysis approach

“…The latter is problematic for comparative studies because venation features change across the surface of a leaf (Nardini et al, 2008; Zwieniecki et al, 2004). Leaves in previous work have been imaged with a scanner (Larese et al, 2014) camera or microscope (Newsome et al, 2020). In the case of P. microcarpa leaves, extreme variability in terms of leaf size meant that a standard section taken from the smallest SS leaves does not cover enough area to be representative of the larger LS leaves, especially given the differences in vein width and length typical for veins of different orders (Roth‐Nebelsick et al, 2001).…”

“…In the case of P. microcarpa leaves, extreme variability in terms of leaf size meant that a standard section taken from the smallest SS leaves does not cover enough area to be representative of the larger LS leaves, especially given the differences in vein width and length typical for veins of different orders (Roth‐Nebelsick et al, 2001). The small size of our sections and their veins necessitated imaging under a stereomicroscope, which has been found to give superior results in some studies (Newsome et al, 2020). A robust foundation to compare many types of leaves even when not exploring dimorphism may also help to prevent biased sampling based on ease of analysis, rather than representing the full range of leaves in a population.…”

ANALISIS MORFOLOGI JAMBU METE (Anacardium occidentale L.) BERDASARKAN KARAKTER VEGETATIF DI TIGA KABUPATEN SULAWESI TENGGARA

“…Hal ini disebabkan karena daun tanaman memberikan respon terhadap arah cahaya matahari untuk proses fotosintesis, sehingga daun akan menyesuaikan tempatnya dan mengakibatkan pertulangan daun menjadi bervariasi. Newsome et al (2020) melaporkan variasi pada pertulangan daun memiliki korelasi terhadap lamina daun. Variasi ini menyebabkan keberagaman pada aspek fisiologi (konduktansi stomata dan efisiensi fotosistem II) dan karakter mikromorfologi (kerapatan dan ukuran stomata).…”