In vitro Screening of Iron Efficient Groundnut Cultivars for Calcareous Soil

Aims: In the present study twenty groundnut genotypes are evaluated for their resistance to IDC and to identify feasible indicators for screening iron (Fe) efficient groundnut genotypes in calcareous soils based on the morphophysiological parameters at 45 days after sowing (DAS).

Study Design: The experiment was replicated three times with two iron treatments (+Fe and – Fe) in a randomized block design

Place and Duration of Study: Field screening of genotypes was carried during Kharif 2019 at Thondamuthur block, Coimbatore district (10°59’31.9” N 76°47’15.4 E), Tamil Nadu, India.

Methodology: The randomized field experiment was comprised of two major factors, i) Fe status (with Fe, without Fe), and ii) genotypes (twenty) with differential IDC response. Seven morpho-physiological parameters associated with IDC resistance were evaluated in groundnut genotypes.

Results: Under Fe deficit conditions, IDC efficient genotypes recorded significantly higher shoot dry weight, root dry weight, root volume, SPAD values, active Fe, catalase activity, peroxidase activity, and higher yield compared to susceptible ones because of better Fe utilization efficiency. The various morpho-physiological parameters studied showed a significant correlation with pod yield. The four genotypes viz., TAG 24, CO 7, VRI 8, and VRI-16086 were efficient under both sufficient and deficit conditions under calcareousness. The stepwise multiple regression shows the peroxidase (POD) accounts for 71 % under +Fe condition and SPAD accounted for 66 percent in -Fe in predicting the pod yield. Hence, POD and SPAD can be used as indicators for selecting Fe efficient groundnut cultivars for calcareous soil.

Conclusion: The findings indicate that SPAD values are most optimal for the initial large-scale screening of groundnut genotypes for tolerance to IDC, whereas peroxidase may be used to validate established genotypes.