Indian Society of Genetics & Plant Breeding

Genetics of resistance to Karnal bunt of wheat [Neovossia indica (Mitra) Mundkur]

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Embryos excised from seeds of six generations (P,. P2,
l , BC" BC2 and F2) of a wheat cross HD29 x HD2329
were cultured on modified MS medium in petriplates
already inoculated with secondary sporidia of Kamal bunt
of wheat [Neovossia indica (Mitra) Mundkur]. Significant
variation for callusing response (CR) (45.55-76.66%) was
observed among generations. Presence or absence of N.
indica did not affect callusing response. A clear inhibition
zone (IZ) was formed around each of the embryo showing
callusing, the diameter of IZ varied significantly among
generations. It was maximum (3.70 cm) in HD29, the
resistant genotype. N. indica was also cocultured with
just initiated calli (from embryos). Fresh weight and dry
weight of calli (observed after 30 days), also varied
significantly among generations. Generation mean
analysis indicated that three-parameter model was
inadequate for CR, fresh weight and dry weight.
Six-parameter modei showed that in presence of N.indica
additive, and additive x dominance effects were significant
for CR, however, in absence of N. indica oniy additive
effects were significant. Duplicate type of epistasis for
fresh weight of calli and dominance and dbminance x
dominance effects for dry weight of calli were observed
in presence of N. indica. Only additive gene effects were
significant for diameter of IZ in both three and six parameter
model, therefore, selecteion might be helpful for improving
resistance to N. indica.

Keywords: Wheat, Kamal bunt, Neovossia indica, callusing, coculturing, fresh and dry weights of calli


Year: 2002
Volume: 62
Issue: 2
Article DOI: NA
Print ISSN: 0019-5200
Online ISSN: 0975-6906



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