Evaluation of field pea accessions for root-knot nematode resistance and possible role of NADP dependent malic enzyme gene in host resistance

Abstract

The present study was undertaken to evaluate resistance
of different field pea accessions to RKN, Meloidogyne
javanica under microplots and pot culture conditions. Three
hundred accessions of field pea were screened initially
using sick soil and evaluated after 2 months of sowing
using root gall index of 1-5 scale. Based on galling index
eleven accessions showing resistant reaction were further
screened under controlled condition. All eleven acessions
were consistent in their response to RKN infection under
pot culture experiment. The partial sequence of NADPdependent malic enzyme (ME) gene was PCR amplified,
sequenced and used to screen field pea accessions
showing resistant and susceptible reaction against RKN
using PCR amplification. PCR screening using ME specific
primers showed PCR amplification only in accessions
showing resistant reaction. There was no amplification of
ME gene from susceptible field pea accessions. The partial
sequence of putative NADP dependent Malic enzyme gene
from resistant accessions of field pea has been cloned and
characterized. The results indicate possible link between
ME and resistance against RKN in field pea. Role of malate
metabolism in generating resistance reaction against RKN
is discussed.