PlantCV v2: Image analysis software for high-throughput plant phenotyping

Systems for collecting image data in conjunction with computer vision techniques are a powerful tool for increasing the temporal resolution at which plant phenotypes can be measured non-destructively. Computational tools that are flexible and extendable are needed to address the diversity of plant phenotyping problems. We previously described the Plant Computer Vision (PlantCV) software package, which is an image processing toolkit for plant phenotyping analysis. The goal of the PlantCV project is to develop a set of modular, reusable, and repurposable tools for plant image analysis that are open-source and community-developed. Here we present the details and rationale for major developments in the second major release of PlantCV. In addition to overall improvements in the organization of the PlantCV project, new functionality includes a set of new image processing and normalization tools, support for analyzing images that include multiple plants, leaf segmentation, landmark identification tools for morphometrics, and modules for machine learning.

Whole-Plant Manual and Image-Based Phenotyping in Controlled Environments

Phenotypic measurements and images of crops grown under controlled-environment conditions can be analyzed to compare plant growth and other phenotypes from diverse varieties. Those demonstrating the most favorable phenotypic traits can then be used for crop improvement strategies. This article details a protocol for image-based root and shoot phenotyping of plants grown in the greenhouse to compare traits among different varieties. Diverse maize lines were grown in the greenhouse in large 8-gallon treepots in a clay granule substrate. Replicates of each line were harvested at 4 weeks, 6 weeks, and 8 weeks after planting to capture developmental information. Whole-plant phenotypes include biomass accumulation, ontogeny, architecture, and photosynthetic efficiency of leaves. Image analysis was used to measure leaf surface area and tassel size and to extract shape variance information from complex 3D root architectures. Notably, this framework is extensible to any number of above- or below-ground phenotypes, both morphological and physiological. © 2017 by John Wiley & Sons, Inc.

[High retention of (99m)Tc-MIBI in delayed phase as a pitfall in the combined parathyroid-thyroid scintigraphy]

Dual phase parathyroid scintigraphy with (⁹⁹m)Tc-sestaMIBI is a very sensitive technique in the preoperative localization and diagnosis of parathyroid adenoma. However, pitfalls have been reported in patients with thyroid nodules with MIBI uptake or with previous thyroid surgery. To solve this problem, a thyroid scintigraphy with (⁹⁹m)Tc-pertechnetate is usually performed following the parathyroid study. Occasionally, as in our patient the parathyroid lesion may show high MIBI uptake and delayed washout that interfere with the subsequent thyroid scintigraphy giving the false appearance of a pertechnetate avid lesion. This has been called the «shine through» effect. To avoid it, the parathyroid and thyroid scintigraphies can be performed on separate days. We have also found it useful to compare our results with that of ultrasound and fine needle aspiration puncture with measurement of the parathyroid hormone (PTH) and thyroglobulin in the aspirated material.

Other Natural Hosts of Potato virus T

Potato virus T (PVT), a member of the genus Trichovirus, was isolated from leaves of naturally infected ulluco (Ullucus tuberosus), oca (Oxalis tuberosa), and mashua (Tropaeolum tuberosum). These Andean tuber crops are often grown in small plots in association with potato (Solanum tuberosum) in the Peruvian highlands. PVT isolates from ulluco, oca, mashua, and potato infected virus-free ulluco, oca, and potato genotypes by mechanical inoculation. The incidence of PVT in mashua, oca, and ulluco accessions from the International Potato Center (CIP) in vitro germplasm bank was less than 10%. A polymerase chain reaction (PCR) product of approximately 330 bp was obtained from each of the four isolates using primers designed from the published PVT sequence. Restriction enzyme digestions of the PCR product did not demonstrate variability.