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  3. 2025

研究成果

Discovery of Cowpea Genetic Resources with Dual Tolerance to Drought and Waterlogging
—A Key Foundation for Developing Varieties Resistant to Extreme Weather from Climate Change—

press202505.pdf2.24 MB

June 13, 2025

Main Points

  • A survey of 99 cowpea genetic lines from the West African dry savanna identified 10 lines (9 wild ancestors, 1 cultivated variety) with dual tolerance to both drought and waterlogging.
  • One wild ancestor line showed the ability to flexibly alter root structure in response to environmental conditions, adapting to both stress types.
  • These stress-tolerant ancestral lines can be crossbred with cultivated varieties, laying the groundwork for developing climate-resilient, stable-yielding cowpea cultivars.

Overview

A research team from JIRCAS and the International Institute of Tropical Agriculture (IITA) has discovered cowpea (Vigna unguiculata) genetic resources that exhibit dual tolerance to two opposing environmental stresses: drought and waterlogging. Cowpea is a key crop in the West African dry savanna region.

With the ongoing impact of climate change, this region has seen an increase in both extreme droughts and heavy rainfall, raising concerns not only about drought, but also about soil waterlogging caused by downpours. Cowpea is an essential protein source for local farming communities. Although breeding has so far focused on drought resistance, there is growing demand for varieties that can tolerate a wider range of soil moisture conditions.

In this study, the researchers evaluated the drought and waterlogging tolerance of 99 cowpea lines (including both cultivated and wild ancestor lines) maintained by IITA. They identified 10 lines (9 wild and 1 cultivated) that demonstrated tolerance to both stresses. Notably, one wild ancestral line developed aerenchyma tissue (air channels) in its roots under waterlogged conditions to enhance oxygen transport, and under drought, it formed structures that improved water uptake efficiency. This ability to flexibly adapt root morphology according to soil moisture conditions was a key discovery.

Additionally, the team showed that multiple physiological and morphological indicators could be used to visualize and evaluate the diverse responses of cowpea genetic resources to varying soil moisture levels.

The identified wild lines are cross-compatible with cultivated cowpeas, suggesting that their stress tolerance traits can be introduced through conventional breeding and genetic analysis. This discovery provides vital insights for developing new cowpea varieties capable of stable production under extreme weather conditions due to climate change, thereby contributing to global food security.

This research was published in the international journal Frontiers in Plant Science, online on June 12, 2025 (Japan time).
 

Related Information

Funding
Operational Expenses Grant Project: "Development of soil and crop management technologies to stabilize upland farming systems of African smallholder farmers"

Publication

Authors
ISEKI Kohtaro, Olajumoke Olaleye
Paper Title
Dual tolerance to soil drought and excess moisture stresses in cowpea genetic resources assessed using multiple indicators
Journal Title
Frontiers in Plant Science
DOI: https://doi.org/10.3389/fpls.2025.1573313

For Inquiries

JIRCAS President: KOYAMA Osamu

Program Director:
FUJITA Yasunari
Research Staff:
ISEKI Kohtaro (Senior Researcher, Biological Resources and Post-harvest Division)
Press Coordinator:
OMORI Keisuke (Head Information and Public Relations Office)
Email: koho-jircas@ml.affrc.go.jp

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