Indices for antioxidant enzymes activity and yield attributes of mash bean [Vigna mungo L. Hepper] genotypes under rhizospheric intensified lead (Pb) concentrations

Abstract

This study was designed to evaluate the toxicity
extent of various Pb2+ concentrations with emphasis on
genotypic variations. Four genotypes of mash bean i.e.
Mash 80, Mash 88, Mash 97 and Mash ES-1 were grown
in pots with four replicates. After twenty days of
germination, various concentrations of lead (10, 20, 30, 40,
50 and 60 mg kg-1
) were added in soil as Pb (NO3)2.
Increasing amount of Pb2+ from 10 mg kg-1
showed a
gradual significant reduction in legume setting, grain
numbers and total yield. The lowest overall reduction was
observed under imposition of 10 mg kg-1
as 3.719% in
legume number, 3.153% in grain number and 6.823% in
total yield. The maximum reduction in yield attributes was
recorded at 60 mg kg-1
in legume number (73.761%), in
grain number (71.179%) and in total yield (92.326%). Among the genotypes, Mash 88 was the most productive
for various yield attributes, while Mash ES-1 was least
productive. The activity of antioxidant enzymes showed a
linear correlation with metal concentration. Ascorbate
peroxidase (APOX) increase was 11.611% at 40 mg kg-1
,
32.81% at 50 mg kg-1
and 49.503% at 60 mg kg-1
.
Superoxide dismutase (SOD) increase was 14.911% at 40
mg kg-1
, 31.939% at 50 mg kg-1
) and 50.058% at 60 mg
kg-1
. Catalase (CAT) increase was 7.092% at 30 mg kg-1
,
13.288% at 40 mg kg-1
, 18.239% at 50 mg kg-1
and
30.140% at 60 mg kg-1
. Superoxide dismutase and catalase
activities were higher in genotypes Mash 88 as 7.451U
mg/g and 34.544 U mg/g, respectively than that in other
genotypes, while the least antioxidant activity was noted in
Mash ES-1. These findings reflect the criteria for selection
of the land regarding toxicity extent of Pb2+ to grow mash
bean in future. © 2020 Department of Agricultural
Sciences, AIOU