Abstract:
Nine cotton genotypes,
comprised of four non Bt males (CIM-1100,
CIM-506, FH-942 and FH-900), five Bt
female genotypes (FH-113, FH-114, MNH-
886, AA-703 and IR-3701) and their 20
crosses were screened in order to evaluate
their response to Cotton leaf curl virus
symptoms through epidemiology in the field
and greenhouse. The 20 crosses among their
nine parents were sown in two replications
under randomized complete block design,
during 2013 and 2014. The mean squares
were significant for all traits indicating that
both additive and non-additive genes control
the characters, but non-additive genes were
more important because, variance of
dominant genes were higher than additive
genes. In our test, FH-900 showed the best
performance against CLCuV, number of
lobes per boll and seed yield. The CIM-
1100 genotype performed well in boll
weight, fiber strength and fiber fineness,
whereas CIM-506 was good for plant
height, number of sympodial branches and
ginning. Maximum boll number, seed index
and fiber length were shown by FH-942.
Among lines, MNH886, FH-113, IR-3701
and FH-114 exhibited the best general
combination for many traits. Hence, parents
were preferred for hybridization program to improve the majority of characters. Hybrids
FH-113 × FH-942, MNH-886 × CIM-1100,
MNH-886 × FH-942, IR-3701 × CIM-506,
AA-703 × CIM-1100, FH-114 × FH-942,
FH-114 × CIM-1100 and MNH-886 × FH-
900 was best in specific combinations for
different traits, especially against CLCuV.
The results indicated that to increase
resistance against CLCuV, hybrids should
be exploited to develop CLCuV resistance.
