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The observations made on these necrotic F1
hybrids showed that the yellowing of leaves started at 2 - 3
leaf stage and most of the hybrids died at the 5 - 6 leaf
stage without producing ear, showing the characteristic of
severe necrosis of grade 7 as described by HERMSEN
(1963).
It is well established that Indian variety C306 carries
Ne1 gene. Therefore, the varieties like
IWP72, WH331, UP262, P48B, Raj 939, CBS289, Cm 58803, Cm
59376, Cm 66675, CBS102, PC89, WL410, Kalyansona, which have
produced necrotic hybrids with C306, carry
Ne2 gene. Similarly, the variety GP104
which did give normal plants with C306 but showed necrosis
with above listed varieties, must have Ne1
gene. Other varieties like GP106, WH157 and AP105 also gave
indication of having Ne1 gene in their
genotypic back-ground. The crosses involving WH331 showed
less necrosis, indicating that this variety may be having
m or w alleles of Ne2 but it
needs further confirmation. There were varieties like WH157,
IWP72 and WL410 which were earlier reported to be
non-carrier of necrotic genes, have now been identified
having Ne1 (WH157) and
Ne2 (WL410 and IWP72) genes. These
information will be of importance to the wheat
breeders/geneticists in their hybridization programme.
References
ANAND, S.C., B.S. GILL & R.P. JAIN 1969. Necrosis in
intervarietal crosses of wheat. Indian J. Genet.,
29(1): 131-134.
CHOWDHURY, R.K. 1981. Hybrid necrosis in wheat. WIS,
53: 40-42.
CHOWDHURY, R.K. 1983. Hybrid necrosis in wheat. WIS,
57: 9-11.
DHALIWAL, H.S., S.K. SHARMA & A.S. RANDHAWA 1986. How to
overcome hybrid necrosis in wheat. WIS, 61/62:
27-28.
GILL, K.S., D.R. VASUDEVA, B.S. GHAI & M.L. GUPTA 1969.
Necrosis in hybrids of Punjab variety C306 and Mexican
varieties of wheat. PAU J. Res., 6: 8-13.
HERMSEN, J.G. Th. 1963. Hybrid necrosis as a problem for
wheat breeder. Euphytica, 12: 1-16.
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