Peter Joseph Matthews

Plastid genome reveals the genetic diversity and phylogenetic relationships of cultivated taro (Colocasia esculenta) in KoreaTaro (Colocasia esculenta) is a culturally and nutritionally important crop with a long history of cultivation in Korea. However, the genetic diversity of Korean taro and its relationship to global taro diversity have not been studied. Here, we report the complete plastid genomes (plastomes) of four cultivated taro samples (CESKR01–CESKR04) from two provinces in South Korea: three from Chungcheongnam-do and one from Jeollanam-do. The plastomes ranged from 162,376 to 162,546 bp and exhibited a GC content, gene composition, and quadripartite structure typical of this species, with a large single-copy region, a small singlecopy region, and a pair of large inverted repeats. Phylogenetic analyses of full-length multiple sequence alignments robustly identified two major plastid lineages (CI and CII) in cultivated taro, as previously reported. CESKR01, CESKR02, and CESKR03 grouped with the temperate-associated CII haplogroup, whereas CESKR04 grouped with the tropical CI haplogroup. These maternal lineages of taro in Korea are presumed to reflect independent introduction histories. Through comparative analyses, we identified seven highly variable loci in the CI and CII lineages that can be used in future characterization of Korean taro. A comprehensive taro sampling strategy is required to investigate the phylogeography of Korean taro in relation to local climate conditions and the global context.

Paper and papermaking have been critical tools in the development of information societies throughout history. Despite their significance, the traditional papermaking and its propagation remains uncertain. This study investigates the potential presence of DNA in traditional paper and papermaking processes using DNA extraction and morphological analysis via acetocarmine and 4’,6-diamidino-2-phenylindole staining. Results provide strong evidence for the survivability and presence of DNA within traditional paper and papermaking processes. This finding has particular significance for Eastern Asian countries, where paper mulberry was the primary fiber source for papermaking. The presence of DNA in traditional paper may influence our understanding of historical trade routes and fiber material propagation, especially concerning paper mulberry species. The taxonomical classification of paper mulberry remains unclear due to its extensive habitat range, rapid hybridization, morphological similarities, and incomplete historical records of species transfers. The discovery of DNA in traditional paper adds biological evidence to this complex issue. This study's findings have significant implications for the stepping-stone of future ethnobotanical research, particularly in relation to paper mulberry species. Additionally, the remained DNA potentially provides new insights into historical trade patterns, cultural exchanges, and the evolution of papermaking techniques across different regions.

Complete chloroplast genomes of 17 samples from six species of Colocasia (Araceae) were sequenced, assembled, and aligned together with two previously reported complete genome sequences from taro (Colocasia esculenta). Analysis provides a well‐supported phylogenetic tree for taro and closely‐related wild Colocasia species in Southeast Asia. Two chloroplast lineages (CI and CII) form a well‐defined haplotype group and are found in cultivated taros known as var. esculenta (dasheen, CI), var. antiquorum (eddoe, CII), and in a widespread, commensal wild form known as var. aquatilis (CI). A third lineage (CIII) is also found in wild taros known as var. aquatilis and in the wild species C. lihengiae, C. formosana, and C. spongifolia. We suggest three different scenarios to explain the grouping of CIII wild taros (C. esculenta) with other wild Colocasia species. Chloroplast lineages CI and CIII in C. esculenta and an unknown parent species may be involved in an as yet undated history of hybridization, chloroplast capture, and range extension. Substantial taxonomic revision may be needed for C. esculenta after further studies of morphological and genetic diversity within the crop, in wild populations, and in closely related wild species. The results also point to the Bengal delta as a region of key interest for future research on the origins of tropical wetland taros.

Colocasia spongifolia sp. nov. (Araceae) is a large herb in forest edges on mountain slopes in southern China and central Vietnam. The plant is remarkable for its distinct vegetative morphology, while floral morphology places it as a close wild relative of C. esculenta (taro), among other closely-related species. The name given here reflects a thick, rubbery, spongy leaf blade unlike the blades in other Colocasia species known to us. The blade has exceptionally large spongy mesophyll cavities that are visible to the naked eye. Vegetative reproduction appears to be limited to direct (though shy) sprouting of lateral buds to form new erect stems, without production of side-tubers or stolons. In contrast to other Colocasia species, dense spreading colonies (clumps or patches) were not seen.

Societal Impact Statement: Using Taro (Colocasia esculenta) as a case study, we examine how perception gaps contribute to negative feedback loops that create or maintain the orphan status of certain crops. For students and researchers seeking uncrowded areas for study, orphan crops and crop‐wild‐relatives offer large open spaces, figuratively and literally. Learning how to see what has not been seen may in turn help us to reduce our global dependence on very few crops, and the risks that follow from this. The combination of climate change and variability and increasing population has painted a dark picture of future food security for many regions in the world where resources are scarce. The key to future food and nutrition security may very well lie in unlocking the untapped potential of orphan and overlooked crops.Summary: The present distribution of taro (Colocasia esculenta), as a cultivated food plant, extends from southern to northern Africa, western Asia to eastern Asia, throughout Southeast Asia and the Pacific Islands, and through the Americas, from the USA to Brazil. Despite its vast geographical range, high nutritional value, and considerable trade as a fresh and processed crop, there has been relatively little interest in taro and its wild relatives among research funding agencies, and little effective or large‐scale assessment of production, trade and usage. Given the proven ability of this crop to grow under diverse climatic regimes, from the equatorial tropics to northern and southern temperate zones it may be useful to consider perception gaps that contribute to disregard of the crop. Here we suggest and discuss a range of perception gaps that together may explain the status of taro as an orphan crop. Perception gaps exist because of many factors: dogma, linguistic diversity, social biases, under‐research, limited physical visibility of living wild populations, poor archaeological visibility, missing production numbers and inaccurate distribution maps. These contributing factors are shared, to lesser or greater extent, by many other orphan crops, but the disjunction between actual utilization (significant) and research effort (minimal) may be greater for taro than for most other “orphans”.

As an ancient clonal root and leaf crop, taro (Colocasia esculenta, Araceae) is highly polymorphic with uncertain genetic and geographic origins. We explored chloroplast DNA diversity in cultivated and wild taros, and closely related wild taxa, and found cultivated taro to be polyphyletic, with tropical and temperate clades that appear to originate in Southeast Asia sensu lato. A third clade was found exclusively in wild populations from Southeast Asia to Australia and Papua New Guinea. Our findings do not support the hypothesis of taro domestication in Papua New Guinea, despite archaeological evidence for early use or cultivation there, and the presence of apparently natural wild populations in the region (Australia and Papua New Guinea).