Scion genotype dominates drought tolerance in grafted Coffea spp. seedlings under severe water stress

Zhiwei Ding; Abdul Majeed Baloch; Li Gong; Abdul Wahid Baloch; Jalil Ahmed; Fayyaz Maqbool; Sheharyar Ali; Yunping Dong; Xuejun Li; Weifeng Li; Zhenjiang Lv

doi:10.3389/fpls.2026.1835057

Scion genotype dominates drought tolerance in grafted Coffea spp. seedlings under severe water stress

Front Plant Sci. 2026 May 20:17:1835057. doi: 10.3389/fpls.2026.1835057. eCollection 2026.

Authors

Zhiwei Ding^#¹, Abdul Majeed Baloch^#¹, Li Gong^#¹, Abdul Wahid Baloch², Jalil Ahmed², Fayyaz Maqbool³, Sheharyar Ali⁴, Yunping Dong¹, Xuejun Li^{1

5}, Weifeng Li¹, Zhenjiang Lv^{1

5}

Affiliations

¹ College of Tropical Crops, Yunnan Agricultural University, Puer, China.
² Department of Plant Breeding and Genetics, Sindh Agriculture University, Tando Jam, Pakistan.
³ Department of Entomology, Sindh Agriculture University, Tando Jam, Pakistan.
⁴ Department of Horticulture, Sindh Agriculture University, Tando Jam, Pakistan.
⁵ Yunnan Key Laboratory of Coffee, Yunnan Agricultural University, Puer, China.

^# Contributed equally.

Abstract

Introduction: Drought is a major abiotic stress limiting coffee production globally. While grafting improves abiotic stress tolerance, the relative contributions of scion and root stock to drought resistance in intraspecific and interspecific grafted Coffea seedlings remain unclear across different stress intensities.

Methods: We hypothesized that scion genotype dominates drought responses under severe water stress, whereas rootstock effects prevail under normal irrigation. To test this, we conducted a 120-day pot experiment using daily weighing and replenishment, with three treatments: normal supply (18-25% soil water), mild drought (15-17%), and severe drought (10-12%). Two C. canephora scions ('Dafeng No.1','Reyan No.5') were grafted onto intraspecific ('Reyan No.2') and interspecific ('Charlie No.16') rootstocks.

Results: 'Reyan No.5' scion conferred superior drought tolerance under severe stress via stronger membrane stability (lower malondialdehyde, MDA), higher osmotic adjustment, and more stable antioxidant defense (super oxide dismutase, SOD; peroxidase, POD; catalase, CAT) .'Dafeng No.1' showed higher water use efficiency (WUE) under mild stress but suffered greater oxidative damage. Principal component analysis confirmed scion genotype explained 44. 78% of total physiological variation.

Discussion: These findings clarify scion dominance in severe drought tolerance and guide drought-resistant coffee grafting selection.

Keywords: Coffea; drought tolerance; interspecific grafting; intraspecific grafting; scion genotype.