Indian Society of Genetics & Plant Breeding
Maydis leaf blight caused by Bipolaris maydis
(Cochliobolus heterostrophus) presently has become a
major disease of maize, causing considerable losses in
productivity. Out of three races C, 0 and T, race '0' is
prevalent in maize tract of India. During last three decades,
though considerable breeding research has been carried
out to improve the productivity, progress with respect to
resistance breeding has been lagging behind with respect
to Maydis leaf blight. Work of all these years have led
to identification of two resistant source inbred lines namely,
CM 104 and CM 105. However, incorporation of maydis
resistance from these two sources have been rather
discouraging. These two sources though possessed high
per se resistance, their capacity to transmit their resistant
gene have not been very fruitful under different background
germplasm. In order to understand the reason behind
such behaviour the genetic study based on combining
ability was undertaken, using these and two other inbred
lines namely CM 119 (susceptible) and CM 206 (moderately
resistant). Using four inbred lines of contrasting resistance
level in a diallel making system, gene action studies were
conducted. Resistance to Maydis leaf blight was found
to be predominantly under the influence of additive gene
action along with significant contributions from '8dditive
x additive epistasis. However, significant role of dominant
gelle action along with epistasis could not be ruled out
entirely.
Keywords: Maize, maydis leaf blight, combining ability, additive gene action, dominance, epistatsis
Year: 2003
Volume: 63
Issue: 1
Article DOI: NA
Print ISSN: 0019-5200
Online ISSN: 0975-6906
R. C. Sharma, S. N. Rai, B. K. Mukherjee1 and N. P. Gupta info_circle
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