Photosynthetic and Molecular Responses of Groundnut Genotypes to Iron Deficiency

The challenge of iron deficiency in calcareous soils significantly inhibits crop growth, causing chlorosis and yield reductions. Screening for promising iron-deficiency-tolerant groundnut genotype for calcareous soils, offer insights into crop stress adaptation and productivity enhancement in challenging environments.

An experiment aimed at understanding the responses of six chosen groundnut genotypes, with one iron-deficiency- tolerant genotype (ICGV 86031) as a control (6+1), was conducted at Acharya N G Ranga Agricultural University, Regional Agricultural Research Station in Tirupati. The investigation encompassed both phenotypic and molecular analyses under conditions of iron sufficiency and deficiency. The selection of these six genotypes was based on their phenotypic traits, emphasizing high physiological performance under iron deficiency stress.

Notably, TCGS-2018 and ICGV 86031 displayed elevated chlorophyll levels and photosynthetic rates compared to other genotypes, regardless of iron availability. Also, ICGV-86031, TCGS-1862 and TCGS-2018 exhibited higher total iron content and demonstrated superior tolerance to iron deficiency stress. Gene analysis of four selected genotypes highlighted higher expression levels of NRAMP family genes in TCGS-2018 under iron deficiency, indicating their role in iron balance. Distinct patterns were observed in the expression of ZIP1 and AhIRT1 genes, which are relevant to iron and zinc balance and varied among genotypes. Overall, these findings underscore TCGS-2018 as a promising iron-deficiency-chlorosis tolerant groundnut genotype offering enhanced productivity for calcareous soils.