Genetic mapping for agronomic, nutritional, and leaf vein traits in the indigenous crop Gynandropsis gynandra

Gynandropsis gynandra is a nutrient-rich, climate-resilient, C₄ under-utilised crop with potential to enhance food security in low-input farming systems. To support its genetic improvement, we performed linkage mapping using two F₂ populations (213 and 187 individuals) derived from Malaysian and Malawian founder lines. Under controlled greenhouse conditions, populations were phenotyped for agronomic traits (plant height, leaf area, flowering time), nutritional content (carotenoids, tocopherols), and anatomical features linked to C₄ photosynthesis (vein density, bundle sheath size). High-density SNP genotyping enabled construction of linkage maps and identification of 15 QTL. Shared QTL for plant size and flowering time across both populations suggest stable genetic control suitable for marker-assisted selection. Additional QTL for vein density and vitamin content provide insights into the genetic basis of agronomic traits and C₄ physiology. These results offer foundational tools for G. gynandra pre-breeding and reinforce its potential as a model for C₄ photosynthesis research and sustainable agriculture.