Screening of F3 population for iron chlorosis tolerance in groundnut under calcareous soils

Abstract

Iron is an important nutrient required for the synthesis of chlorophyll, photosynthesis, respiration and assimilationof nitrogen and sulphur. Iron is present in large quantities in the soil but mainly in the forms that are not available to plants.Iron deficiency is an important abiotic constraint reducing growth and yield of groundnut especially under calcareous soils.One of the ways to address the issue is breeding for genotypes tolerant to iron chlorosis. Keeping this in view breeding wasinitiated and advanced. In this context, F3 populations of two crosses TMV 2 × ICGV 86031 (TIP) and JL 24 × ICGV86031 (JIP) were screened for chlorosis tolerance along with parents during kharif-2018. Among F3 populations, theprogenies TIP 6, TIP 16 of TMV 2 × ICGV 86031 (TIP) and the progenies JIP 27 and JIP 29 of JL 24 × ICGV 86031 (JIP)were found superior as compared to susceptible parents TMV 2 and JL 24, respectively for visual chlorotic ratings (VCR),SPAD chlorophyll meter readings (SCMR) and morphological traits. The estimates of variance components revealedpredominance of additive component of variance for the characters studied. The progenies TIP 6, TIP 16, JIP 27 and JIP 29also recorded more number of pods per plant, total dry matter and pod weight compared to tolerant variety, ICGV 86031and their susceptible parents, TMV 2 and JL 24. The chlorosis tolerance in the selected progenies might be due to higheracquisition of iron in calcareous soils mainly indicated by higher greenness leading to increase in photosynthesis, growthand yield