Arvind Kumar, M.N. SHRIVASTAVA
and B.C. SHUKLA
Indira Gandhi Agricultural
University, Raipur492 012, M.P. India
We studied the mode of inheritance
of resistance to gall midge in rice cultivar RP2333-
156-8. Parents and segregating populations were screened
under field conditions at Regional Agricultural Station, Bilaspur. The
level of infestation was very high as the susceptible parents showed 100%
infestation on single plant basis (Table 1).
The populations from the crosses
of RP2333-156-8 with susceptible parents R 2270, Ratna and Shymala segregated
in the ratio of 3 resistant to 1 susceptible (Table 2) indicating that
RP2333-l56-8 has one dominant gene for resistance. Their F3 progenies segregated
into 1:2:1 ratio representing respectively breeding true for resistance,
segregating and breeding true for susceptibility, confirming the presence
of a single dominant gene for gall midge resistance in RP 2333-156-8.
The F2 populations of RP 2333-156-8
with parents possessing known gene for resistance to gall midge, e.g. Gm
1 (Samridhi, Ruchi and Asha), Gm 2 (Phalguna), Gm 4 (Abhaya) and Gm 5 (ARC
5984) segregated into 15R:1S ratio, indicating the non-allelic nature of
the gene of RP 2333-156-8 with Gm 1, Gm 2, Gm 4 and Gm 5. The F2 populations
of RP 2333-156-8 with RP2068- 18-3-5, having gm3, the recessive gene for
gall midge resistance segregated into 13R:3S ratio, indicating the non-allelic
nature of the gene of RP 2333-156-8 with gm 3 (Table 2). The F3 population
of this cross segregated into 7R:8Sg:1S ratio confirming the non-allelic
nature of the gene of RP 2333-156-8 with Gm 1, Gm 2, gm 3, Gm 4 and Gm
5. Rice variety Duokang 1, from China having Gm 6 is susceptible to gall
midge biotype 1 of India. The gene for resistance of RP 2333-156-8 is therefore
different from Gm 6. We have therefore designated this gene as Gm 7.
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