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

Breeding for Resistance/Tolerance to Biotic, Abiotic and Environmental Stresses
Table 21. Trait mean values, ranges, standard deviation and F-statistic from analysis of variance of grain yield
and its components of RIL population of Kalinga III /Salumpikit
RILs Standard
Trait Kalinga III Salumpikit Range Mean Deviation F- Statistic
Days to flower 63 93 53-105 78.9 10.6 35.11**
Plant height (cm) 84.1 118.4 52.9 - 145.5 103.4 13.1 1.854**
Biomass (g./plot) 150.3 154.4 30 - 450 233.7 87.4 1.221
Panicle length (cm) 18.9 20.3 14.7 - 27.3 20.0 2.2 2.019**
Filled grains per panicle 14 59 0 - 90 27.2 18.0 2.29**
Percent spikelet sterility (%) 78.4 35.9 11.4 - 100 62.2 22.2 2.906**
Canopy temp. (ºC) 35.1 33 27.2 - 38.6 32.6 2.7 0.958
Drought score (SES) 7 3 1 - 7 4.0 1.6 2.99**
Grain yield (kg ha -1 ) 69.1 539.2 0 - 1181 331.3 258.8 3.622**
Table 22. Correlation matrix among different traits under stress condition
Plant Grain Drought Canopy Panicle Filled
Days to height yield score temperature length grains
Trait flower (cm) Biomass kg ha 1 (SES) (ºC) (cm) panicle -1
Plant height (cm) 0.15
Biomass 0.10 0.24
Grain yield (kg ha 1 ) 0.23 0.34* 0.28
Drought score (SES) -0.11 -0.19 -0.18 -0.45**
Canopy temp. (ºC) 0.03 -0.10 -0.05 -0.07 0.10
Panicle length (cm) 0.16 0.21 0.12 0.22 -0.19 -0.16
Filled grains per panicle 0.27 0.35 0.16 0.77** -0.34* -0.04 0.25
Percent spikelet sterility (%) -0.29 -0.34 -0.10 -0.74** 0.30* 0.01 -0.14 -0.92**
would likely be accompanied by improvement of filled
grain number (Table 22). Negative correlations (r=-0.74)
between grain yield and per cent spikelet sterility and
between grain yield and drought score (r=-0.45) were
also highly significant, though the magnitude of the
later is not very high.
Identification of QTLs associated with traits conferring
weed competitiveness
Heera and Browngora have been screened for parental
polymorphism with 204 SSR markers, of which
85 were found to be polymorphic. The mapping population
of the cross Heera/Browngora was advanced
from F 7
to F 8
during wet season 2011. One hundred nine
recombinant inbred lines (RILs) along with parents were
evaluated for traits associated with weed competitiveness
under once weeded and weed free conditions.
Reduction in grain yield under weedy condition in red
soil was 68% whereas, it was 28% under clay soil. In
red soil, grain yield under once weeded condition
ranged from 0.007 to 1.06 t ha -1 , whereas under weed
free condition it ranged from 0.10 to 2.21 t ha -1 . In clay
soil, grain yield under once weeded condition ranged
from 0.35 to 1.92 t ha -1 whereas, under weed free condition
it ranged from 0.53 to 2.35 t ha -1 . However, days to
50% flowering was not influenced by weeds in both
red soil and clay soil conditions.
QTL-NIL development–Blast
The cycle of backcrossing for transfer of two genes
(Pi2 and Pi9) in the background of Vandana was advanced
and confirmed plants (Fig. 13) selected for
selfing. Simultaneously, flanking markers on either side
of the gene based SSR marker AP 5930, used for both
Pi2 and Pi9 and polymorphic between the parents have
been identified for recombinant selection on the target
chromosome. Around 30 HV SSR markers selected from
chromosome 6 were used for background selection out
of which five HV SSR were polymorphic between the
recurrent and donor and situated on either side of the
target gene. Among the five confirmed plants (Fig. 14),
four were similar to the recurrent parent based on these
polymorphic plants.
A population of 266 RILs of Kalinga /Moroberekan,
developed by single seed descent, for abiotic and biotic
stress tolerance was evaluated for blast and brown spot
CRRI ANNUAL REPORT 2011-12
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