Central Rice Research Institute Annual report...2011-12

Breeding for Resistance/Tolerance to Biotic, Abiotic and Environmental Stresses
were selected for foreground selection. Among these
primers RM521 and RM520 have given clear polymorphism
for DTY 2.1
and DTY 3.1
QTLs, respectively. Two
plants found positive for both the QTLs (DTY 2.1
& DTY 3.1
)
were used for backcrossing with Swarna-Sub1. Seventy
two crossed seeds (BC 2
F 1
) have been harvested. During
2012 dry season, seventy-two BC 2
F 1
plants were subjected
to foreground selection. Gene specific markers
RM521, RM520 and Sub1BC 2
were used for identifying
positive plants with DTY 2.1,
DTY 3.1
and Sub1 QTLs respectively.
Eleven positive plants were obtained with
both drought QTLs (DTY 2.1
and DTY 3.1
) along with Sub1
locus. Selected 11 BC 2
F 1
plants were subjected
tobackground selection with polymorphic STMS markers
present across 12 Chromosomes in the rice genome.
Selected plants were used for back crossing. One hundred
and seventy crossed seeds (BC 3
F 1
) were harvested.
Introgression of Sub1 QTL into Pooja and
Pratikshya for flooding tolerance
During the wet season 2011, F 1
plants of two crosses
viz., Pooja/Swarna-Sub1 and Pratikshya/Swarna-Sub1
were grown along with the respective parents. Four
primers viz., IYT1, IYT3, Sub1A203 and AEX used for
confirmation of Sub1 QTL presence in F 1
plants showed
dominant nature of these markers. Two primers RM8300
and Sub1BC2 showed co-dominant nature and seedlings
with Sub1 locus showed heterozygous condition.
Confirmed plants were used for backcrossing with the
recurrent parents, Pooja and Pratikshya (Fig. 16 & 17).
Based on PCR results selected F 1
plants of the both the
crosses, Pooja/Swarna-Sub1and Pratikshya/Swarna-
Sub1 were used for backcrossing with the respective
recurrent parents. More than one thousand seeds
(BC 1
F 1
) of each cross were harvested.
Introgression of Saltol QTL into Gayatri for
salt tolerance
During the wet season 2011, F 1
plants of the cross
Gayatri/FL478 were grown along with parents. Out of
the ten primers used for identifying the F 1
plants with
‘Saltol’, three gene specific markers (RM8094, AP3206
and RM3412) and two flanking markers (RM493 and
RM7075) showed co-dominant/heterozygous condition,
whereas, other primers did not show any polymorphism.
Primer, RM493 was used for selecting the F 1
plants with Saltol QTL, which showed a clear polymorphism
between plants with and without ‘Saltol’. On
the basis of PCR analysis, selected F 1
plants with ‘Saltol’
were used for backcrossing with the recurrent parent
Gayatri and about 600 BC 1
F 1
seeds were obtained.
Fig. 16. Presence of Sub 1 locus in heterozygous condition in F 1
plants (Pooja/Swarna-
Sub 1) in PCR amplification with Sub 1 QTL spcific marker Sub 1 BC2 primer; M=100bp
DNA ladder
Fig. 17. Presence of Sub 1 locus in heterozygous condition in F 1
rice plants (Pratikshya/
Swarna-Sub1) in PCR amplification with Sub 1 QTL spcific marker Sub 1 BC2
CRRI ANNUAL REPORT 2011-12
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