How different chickpea types cope with toxic chromium in the soil

Jim Crocker
31st January, 2026

How different chickpea types cope with toxic chromium in the soil

Increasing concentrations of hexavalent chromium caused a dose-dependent reduction in germination (a) and seedling development in Chickpea (Cicer arietinum), yet variety CM-72 (b) visibly demonstrated superior tolerance and maintained better growth compared to the sensitive variety CM-98 (c).

Image adapted from: Hammad et al. / CC BY (Source)

Key Findings

  • In Pakistan, chickpea crops are vulnerable to hexavalent chromium (Cr VI) contamination from industrial waste, impacting yield and food security
  • Chickpea variety CM-72 showed greater tolerance to Cr VI stress than CM-98, maintaining higher germination rates and less growth reduction
  • Higher Cr VI concentrations consistently reduced germination, root/shoot length, and biomass in both varieties, but the impact was less severe in CM-72
Hexavalent chromium (Cr VI) contamination in soil, largely stemming from industrial activities, poses a significant and growing threat to agricultural productivity, particularly in regions like Pakistan where concentrations in agricultural lands are frequently exceeding safe limits[1]. This contamination impacts not only crop yields but also potentially enters the food chain, raising concerns for human health. Chickpea, a vital crop in Pakistan, is particularly vulnerable to Cr VI stress, prompting research into how different varieties respond to this toxic element. The problem of heavy metal contamination in agricultural soils is well-documented[2]. Chromium, along with metals like arsenic, lead, and cadmium, can disrupt plant metabolic processes, reducing crop health and overall yield. The severity of the impact depends on factors such as the type of crop, the concentration of the metal, and the soil’s properties. Ultimately, this contamination can lead to the accumulation of heavy metals in edible plant parts, exposing humans to a range of health risks, including damage to the kidneys, brain, and other vital organs[2]. Researchers from Thal University, Punjab, and the University of Agriculture recently conducted a study to investigate the differential responses of two Pakistani chickpea varieties – CM-72 and CM-98 – to varying levels of Cr VI stress. The research addressed a critical knowledge gap by examining how these varieties perform under controlled conditions, ranging from no Cr VI exposure (0µM) up to a concentration of 100µM. The study employed a controlled experimental design, carefully monitoring key seedling characteristics over a 14-day period. These included germination rates, root and shoot lengths, root collar diameter (a measure of stem thickness), and overall biomass. The results revealed substantial differences between the two varieties. Both CM-72 and CM-98 experienced dose-dependent reductions in all measured parameters as Cr VI concentration increased, indicating that higher levels of chromium stress negatively impacted their growth. However, CM-72 consistently demonstrated greater tolerance to the toxic effects of Cr VI. Specifically, at a concentration of 100 µM Cr VI, CM-72 achieved a germination rate of 90% compared to 80% in CM-98. Similarly, CM-72 showed smaller declines in root length (39% reduction) and shoot length (76% reduction) compared to CM-98 (77% and 90% reductions respectively). The difference in biomass was also notable, with CM-72 experiencing a 34% dry weight loss, while CM-98 suffered a 59% loss. Statistical analysis, including ANOVA (a method for comparing means), Pearson correlation (measuring the strength of relationships between variables), and PCA (Principal Component Analysis – a technique for simplifying complex data), confirmed these varietal differences and identified strong links between growth inhibition and chromium stress. PCA further revealed that the effects of Cr VI were both structural, impacting features like root collar diameter, and temporal, causing delays in germination. These findings align with previous research highlighting the varying sensitivities of plants to heavy metal contamination[2]. The study builds on this understanding by specifically demonstrating the resilience of CM-72 under Cr VI stress. This resilience is likely due to inherent metabolic and antioxidative adaptations within the variety, although the precise mechanisms remain to be fully elucidated. The study’s implications are significant for regions like Pakistan, where chromium contamination is prevalent[3][4]. The identification of CM-72 as a more tolerant variety offers a potential pathway towards sustainable agricultural practices in affected areas. Furthermore, the research underscores the importance of understanding the specific responses of different crop varieties to heavy metal stress, allowing for informed selection of cultivars that can maintain productivity even in contaminated soils. The research team suggests that future studies should focus on pinpointing the underlying physiological and biochemical traits responsible for CM-72’s tolerance, which could potentially be harnessed through breeding programs to develop even more resilient chickpea varieties.

AgricultureEnvironmentPlant Science

References

Main Study

1) Differential seedling responses of chickpea varieties to hexavalent chromium (VI) stress under controlled conditions

Published 29th January, 2026

https://doi.org/10.1371/journal.pone.0341546

Related Studies

2) Sources, effects and present perspectives of heavy metals contamination: Soil, plants and human food chain.

https://doi.org/10.1016/j.heliyon.2024.e28357

3) Chromium Pollution in European Water, Sources, Health Risk, and Remediation Strategies: An Overview.

https://doi.org/10.3390/ijerph17155438

4) Chromium contamination in paddy soil-rice systems and associated human health risks in Pakistan.

https://doi.org/10.1016/j.scitotenv.2022.153910


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