Assessment of nodulation potential in mini-core genotypes and land races of chickpea

Abstract

Symbiotic nitrogen fixation (SNF) is a sustainable alternative for nitrogen supply for plants in agriculture. Past efforts to enhance SNF in chickpea through inoculation with improved rhizobia were partially successful. Hence, there is an urgent need to identify nodulation variants among the mini-core and races accessions of chickpea. In the present study, a total of 211 mini-core lines, 68 land races and 3 checks were evaluated for nodulation variants under greenhouse conditions at ICRISAT, Patancheru, India and IIPR, Kanpur, India. The seeds of all accessions were inoculated with IC-76, a nodulating bacteria, on both locations. When the potting material was pasteurized, the organic carbon had reduced from 0.49% to 0.29% whereas no significant difference was noted in total N and available P contents. At 45 days after sowing, the mini-core lines of chickpea were categorized into 6 types, based on nodulation capability (rating 0-5, where 0=no nodules; while 5 = maximum nodules) at both ICRISAT and IIPR locations. A direct correlation was obtained between nodule numbers and shoot and root weights. Further, some lines were found common at both the locations for particular category of nodulation rating.For instance, the lines ICC-2580, ICC- 2990, ICC-3421 and RSG-888 were found fitting in rating 5 while lines ICC-6294 and ICC-9002 in rating 1. A similar trend of nodulation variants were also found in the land races of chickpea. A total of 35 chickpea mini-core lines and six land races were found common for nodulation variants at both locations.