Nature's Colorful Cornucopia
In the heart of Borneo, a humble root vegetable reveals astonishing variations that may hold keys to food security.
Deep in the rich soils of Kalimantan, the Indonesian portion of Borneo, grows a plant that has sustained local communities for generations—taro (Colocasia spp.). This ancient crop, with its distinctive broad leaves and starchy corms, represents one of the oldest forms of cultivated plants in the region. Beyond its role as a staple food, taro holds a secret: an astonishing diversity of forms that has long fascinated scientists and farmers alike.
Taro is one of the world's oldest cultivated crops, with evidence of its domestication dating back over 10,000 years in Southeast Asia.
Recent research has uncovered the remarkable morphological variability of taro in Kalimantan, revealing not just a single crop but a spectrum of genetic treasures. Through the science of phenetic analysis, researchers have documented how this plant has adapted and diversified across the island, resulting in a colorful array of varieties each with unique characteristics. This hidden diversity represents not just a scientific curiosity but a potential key to future food security in a changing world 1 .
Phenetics, also known as numerical taxonomy, is a scientific approach that classifies organisms based on their overall similarity in observable characteristics. Unlike methods that focus solely on evolutionary relationships, phenetic analysis examines a suite of morphological traits—from leaf shape and petiole color to corm size and stolon structure—to determine relationships between different accessions.
For a crop like taro that has been propagated and selected by local communities for centuries, phenetic analysis provides a powerful tool to document and understand the richness that has emerged through both natural processes and human selection.
In 2019, a comprehensive study sought to document and analyze the morphological diversity of taro across all Indonesian provinces of Kalimantan. This ambitious research effort collected and evaluated 123 distinct taro accessions using 39 different morphological traits related to leaves, petioles, stolons, and corms 1 .
Taro Accessions
Morphological Traits
Species Identified
Local Cultivars
Researchers gathered taro samples from across all Indonesian provinces of Kalimantan, ensuring broad geographical representation 1 .
Each accession was evaluated using 39 morphological characteristics, capturing variations in leaves, petioles, stolons, and corms 1 .
The Gower general similarity coefficient was applied to quantify the degree of similarity between different accessions 1 .
The UPGMA method was used to group accessions based on their overall similarity, resulting in a dendrogram that visualized relationships 1 .
PCA was employed to identify which morphological traits contributed most to the observed variation 1 .
Based on the analysis, accessions were classified into different species and subgroups 1 .
The study revealed several surprising aspects of Kalimantan's taro diversity that had previously been undocumented in scientific literature.
The research confirmed that taro in Kalimantan includes multiple species: C. esculenta, C. affinis, Colocasia sp., and a Colocasia wild type. Among these, C. esculenta was identified as the most widely used as staple food by local residents and was found to have two distinct botanical varieties 1 .
| Species Name | Significance | Utilization |
|---|---|---|
| C. esculenta | Most common species | Primary staple food |
| C. affinis | Less common species | Limited utilization |
| Colocasia sp. | Unspecified species | Varies by local community |
| Colocasia wild type | Wild relative | Potential breeding resource |
Perhaps even more significantly, the researchers identified 52 local cultivars that had developed from C. esculenta varieties, demonstrating the remarkable diversification that had occurred through both natural processes and human selection 1 .
The cluster analysis revealed a fascinating pattern of relationships, with similarity coefficients ranging from 0.615 to 0.974. The taro accessions were divided into two major clusters, with the first cluster containing Colocasia sp. as a single subgroup, and the second cluster comprising six subgroups that included C. esculenta, C. affinis, and the Colocasia wild type 1 .
| Cluster Group | Subgroups | Contents |
|---|---|---|
| First Cluster | 1 subgroup | Colocasia sp. |
| Second Cluster | 6 subgroups | C. esculenta, C. affinis, Colocasia wild type |
One of the most striking findings was the significant influence of petiole color on taro grouping in Kalimantan. This characteristic emerged as a key distinguishing feature among varieties, suggesting that visual cues easily recognizable by local farmers have paralleled genetic differentiation 1 .
To conduct this comprehensive analysis, researchers employed various specialized techniques and tools. Understanding these methods helps appreciate the rigor behind the findings.
| Research Tool | Function | Application in Taro Research |
|---|---|---|
| Morphological Traits Assessment | Documenting physical characteristics | Evaluating 39 traits across leaves, petioles, stolons, corms |
| Gower General Similarity Coefficient | Measuring similarity between accessions | Quantifying degree of relatedness between taro varieties |
| UPGMA Cluster Analysis | Grouping similar accessions | Identifying patterns in taro diversity |
| Principal Component Analysis (PCA) | Identifying most influential traits | Determining which characteristics drive variation |
| Multivariate Statistical Program v.3.1 | Data analysis software | Constructing dendrograms and performing statistical analysis |
Systematic evaluation of physical traits to quantify plant diversity.
Advanced statistical methods to identify patterns and relationships.
Grouping similar accessions to visualize relationships and diversity patterns.
The documented diversity of taro in Kalimantan extends far beyond academic interest, holding significant practical implications for food security, agricultural resilience, and cultural preservation.
Taro represents a potential future alternative crop that could contribute to diversifying agricultural systems in the face of climate change and evolving pest pressures 1 .
The characterization of its variability provides essential information for breeding programs aimed at developing improved varieties with enhanced yield, nutritional quality, or resistance to stressors 1 .
Documenting this diversity creates a baseline for protecting genetic resources that might otherwise be lost as agricultural systems modernize and traditional farming practices decline.
This research highlights the importance of indigenous knowledge and traditional cultivation practices in maintaining crop diversity.
The 52 local cultivars identified in the study represent a valuable genetic treasury that could offer traits for future crop improvement. Local farmers in Kalimantan have been instrumental in selecting and preserving diverse taro varieties, demonstrating the value of combining traditional wisdom with scientific analysis.
The morphological variability of taro in Kalimantan represents a living library of genetic diversity that has evolved through both natural processes and human selection. The phenetic analysis approach has revealed patterns of similarity and difference that provide crucial insights for conservation and utilization of this important crop.
As we face growing challenges in global food security, understanding and preserving crop diversity becomes increasingly urgent. The colorful array of taro varieties in Kalimantan, with their different petiole colors, leaf shapes, and corm characteristics, offers not just aesthetic variety but practical solutions for future agricultural needs.
This research reminds us that biodiversity exists not just in remote wilderness but in the cultivated fields of traditional farmers. By documenting, understanding, and preserving this diversity, we honor generations of agricultural innovation while safeguarding resources for generations to come. The taro fields of Kalimantan stand as a testament to nature's creativity and human ingenuity—a colorful cornucopia waiting to be fully explored.