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

Genetic Enhancement of Yield
N level (N 80
) with 7 popular varieties as checks viz., IR
36, IR64, Vijetha, Pusa44, Tapaswini, Surendra and
Indira. At N 40
level, entry No. 4 (Lalat/Tapaswini 3-1-
1) and entry No. 1 (Vijetha/N22 8-2-8) were the superior
yielders with 4.38 t ha -1 . Entry No. 24 (Lalat/
Supriya 1-2-1) and entry No. 3 (Lalat /IR 36 -15-1-1)
yielded 4.31 t ha -1 and 4.27 t ha -1 , respectively that were
either at par or better than the checks.
At N 80
level, entry No. 109 (IR-36/Vijetha-3-1-1) gave
a yield of 4.50 t ha 1 followed by entry No.86 (IR-36/
Vijetha 20-2-1) with 4.47 t ha -1 and Entry No. 60 (IR-36/
Pusa 44 12-1-1) with 4.42 t ha -1 were better than checks.
Evaluation, selection and advancement of
breeding materials of F 4
, F 5
and other
segregating generations
Around 1200 promising lines of F 4
and F 5
generations
were evaluated under low nitrogen level (N 30
) and
also at moderate N level i.e. N 60
and selected 1600 promising
single plants with desirable features like high
yield, long panicles, high grain number, long slender
and long bold grain with high grain weight. Similarly,
around 20 F 2
crosses from mid duration group and 35
F 2
crosses of long duration group were evaluated at
low nitrogen level and selected around 600 single
plants for further evaluation based on yield and other
desirable features.
Breeding for Fe toxicity and zinc deficiency
tolerance
Evaluation of around 420 F 5
single plant progenies
at zinc deficient site of Ranital farm involving crosses
of IR36, Ratna, Abhaya and Gajapati (Zinc deficient
tolerant genotypes) with popular irrigated genotypes
like Tapaswini, Surendra, Vijetha, Pusa44 was conducted
and selected around 280 single plants for further
advancement based on non-bronzing symptom
and higher yield. Also evaluated 19 crosses of F 2
generation
and selected around 150 single plants for further
evaluation based on tolerant to zinc deficiency i.e.
non appearance of leaf bronzing at 15-30 DAT with
SES score 1 and 3. In iron toxicity tolerance evaluation
around 480 single plant of F 4
generations and 18 F 2
generation crossed with tolerant genotypes Gitanjali,
Surendra, Swarna and Lalat, with Savitri, Ranjit,
Salivahana, Pooja and Sambha Mahsuri and selected
320 F 5
plants and 160 F 3
plants without bronzing symptom
under iron toxic soil of Central Farm, Bhubaneswar
for further evaluation. The same set of breeding materials
was grown at CRRI to evaluate their performance
under non stress environment and selected 100 plants
based on yield and other agronomic criteria only.
Breeding for High Temperature Tolerance
in Irrigated Rice
Evaluation of germplasm and genotypes for
heat stress tolerance
Seventy four germplasm accessions evaluated and
shortlisted earlier for heat stress tolerance were reevaluated
by staggered sowing and planting so as to expose
them to heat stress at reproductive stage along with
susceptible checks (Satabdi, Naveen and Lalat) and
tolerant check (N22, Annapurna and Dular). Out of
these, 14 genotypes showed high spikelet fertility an
indicator of reproductive stage heat stress tolerance
even when flowered at higher temperature period. The
most tolerant genotypes with high spikelet fertility, percentage
were AC39843 (88.36%), AC39123 (88.07%),
AC607 (87.74%) and AC39940 (87.25%) and N22(87.25).
Evaluation, selection and advancement of
breeding materials for heat stress tolerance
Around 450 single plant selections of F 4
lines involving
promising irrigated cultivars like Tapaswini,
Lalat, Surendra, Pusa44, Vijetha, Shatabdi, IR36,
Sasyasree and heat tolerance genotype N22,
Annapurna, ADT43 and Dular were selected for heat
stress situation by delayed sowing and planting. Based
on high spikelet fertility, higher grain yield, high harvest
index (HI) and other agronomic features 530 single
plant selections were made for further advancement.
The same 530 materials were evaluated during wet season
2011 for their performance and selected around
480 single plants of F 6
generation for further advancement.
Varietal Improvement for Rainfed Unfavorable
Lowlands
Development of varieties of medium and midlate
duration with major biotic and abiotic
stress tolerance (drought) for unfavorable
shallow lowlands
Ten new crosses were made with Savitri, Gayatri,
Swarna, Pooja and Lalat as ovule parents and drought
tolerant lines CR143-2-2, Mahulata, Kalakeri, Bramani
Nakhi and Naliakhura as pollen parents to improve
drought tolerance, blast resistance and panicle characters
for unfavorable lowland ecosystem. More than 30
bulks were selected and more than 300 single plant
selections possessing desirable characters were made.
CRRI ANNUAL REPORT 2011-12
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