Host specificity of blast fungus (Magnaporthe grisea)
was examined on four finger millet (viz., K7, GE5230,
GPU26, PR202) and one local landrace of foxtail millet using
F1 progenies of a cross between two highly fertile and
host specific pathogenic cultures isolated from a
collection of field samples at central Himalayan region of
Uttarakhand state in India. Parental isolate VII739 was
virulent on finger millet and avirulent on foxtail millet
cultivars, contrarily VII769 showed virulent reaction on
foxtail millet and avirulent on finger millet cultivars. Data
revealed that pathogenicity developed from the cross
between finger millet isolates and foxtail millet isolate
was conditioned by one (on K7 and PR202) and two (on
GE5230) genes. The segregating ratio for 1:1:1:1 and 3:1:3:1
in combined analysis between K7 and PR202 and between
PR202 and GE5230, respectively suggested that genes
present in the cultivars were different and independent,
contrarily 2:0:1:1 ratio between cultivars K7 and GE5230
demonstrated that one gene in GE5230 was identical to
the one in K7. Avirulent genes for pathogen on K7, PR202
and GE5230 were designated respectively as AVR1, AVR2
and (AVR1, AVR3) and their corresponding resistance
genes in cultivars as R1, R2 and (R1, R3). Avirulent reaction
on GPU26 and foxtail millet cultivar explained that complex
host species specificity of M. grisea existed in nature.
Keywords: Magnaporthe grisea, finger millet, foxtail millet, resistance
Year: 2013
Volume: 73
Issue: 2
Article DOI: 10.5958/j.0975-6906.73.2.026
Print ISSN: 0019-5200
Online ISSN: 0975-6906
R. K. Srivastav, R. P. Bhatt info_circle
B. B. Bandyopadhyay info_circle
J. Kumar info_circle