ICRISAT Archival Report 2006 - The seedlings of success in the ...

ICMB 89111. Seven of the selected progenies flowered in 54 days and 2 in 55 days, while 3 flowered in 56 days
(ICMB 89111-P 2 flowered in 54 days and ICMB 89111 flowered in 52 days).
KN Rai and RP Thakur
Restorer line (R-line) development: A restorer development and dissemination strategy, similar to that followed
for A-lines, was initiated in 2006. Nine 2006-series R-lines (5 A 1 cytoplasm and 4 A 4 cytoplasm) with 46−60 days to
flowering and 11−30 cm panicle length were developed for dissemination. Under high disease pressure in the green
house (>95% DM incidence in susceptible check 843B), eight of these were highly resistant (0−10% DM incidence)
to four of the five diverse pathotypes (Durgapura, Jodhpur, Jalna, Jamnagar and Patancheru) and one was resistant to
two pathotypes (Durgapura and Jodhpur). About 60 A 4 restorer progenies (S 7 -S 12 ) were evaluated during the rainy
season, of which 42 were selected with 33 of these flowering in 46−60 days (checks ICMR 356 flowered in 49 days
and ICMP 451 in 52 days).
In 2005 rainy season, 62 potential A 4 R-lines had been identified based on the limited testcross evaluation of their
fertility restoration. These were crossed on 2 A 1 and 6 A 4 male-sterile lines. Results showed that 44 of these were A 1
restorers, 32 were A 4 restorers (fertility restoration proven on at least on 4−6 A-lines), and 24 were dual-restorers.
Of these, 25 lines flowered in 49−55 days, and 37 lines flowered in 56−62 days (ICMP 451 flowered in 52 days).
All the 62 potential restorers were tested for resistance to Durgapura and Jalna pathotypes, of which 34% were
highly resistant (95% DM incidence against both pathotypes).
About 80 additional potential restorer progenies were crossed on both 81A 1 and 81A 4 during the postrainy season
and the resultant testcross nursery was evaluated for fertility restoration during the rainy season. Of these, 50
showed fertility reaction on 81A 1 , 29 on 81A 4 , and 11 on both 81A 1 and 81A 4 .
Restorer line yield trial: Two dual-purpose restorer progenies with large morphological differences for panicle
length/girth and seed size, but expected to have high gain yield were compared with three commercial varieties
(ICTP 8203, WC-C 75 and Raj 171) and a commercial hybrid (ICMH 356) for grain yield in a 5-replication yield
trial at Patancheru during the 2006 rainy season. Raj 171 was the highest-yielding variety (1533 kg ha -1 grain yield)
with 49 days to flower, 170 cm plant height, 22 cm panicle length, 1.5 panicles plant -1 and 8.4 g of 1000 seed mass.
Both inbred lines had 70% of the grain yield of Raj 171, flowered in 52 days, with tillering ability similar to Raj
171, and 30−35 cm shorter height. While the MC 94-derived inbred line had 2 cm longer panicle than Raj 171 and
9.3 g of 1000-seed mass, the long panicle line had 39 cm long panicle and smaller seed (6.7 g 1000-seed mass).
KN Rai and RP Thakur
Milestone 5A.1.1.2: Seed parents and restorer parents adapted to arid zone developed (KNR/RB/FRB/RPT/RS,
2010)
Hybrid parents adapted to western Rajasthan: The Sehgal Foundation provided 3-year funding support in the
year 2002 to increase the emphasis on breeding seed parents specifically adapted to arid Rajasthan. During the third
year of the project, restorer line breeding was also included in this project. Although the project ended in 2004, the
materials generated from this project have been carried forward.
Seed parent progenies: Two types of materials were generated that have been further evaluated and advanced: (i)
progenies derived from ICRISAT-CAZRI B-composite (ICCZBC) that was constituted from a set of diallel crosses,
and (ii) progenies derived by pedigree breeding in some of the most promising B × B crosses in the above diallel.
About 275 S 4 progenies derived from ICCZBC were evaluated during the 2006 rainy season, of which 86 were
selected, with 34 of these flowering in 41−50 days and 48 flowering in 51−55 days (checks 843B flowered in 44
days and 81B in 56 days). Another 268 S 3 progenies were evaluated in the summer drought nursery, of which 152
were selected based on the visual agronomic evaluation. Of these, 21 progenies flowered in 46−50 days and 91
flowered in 51−55 days (checks 843B flowered in 47 days and 842B in 55 days).
We also evaluated 191 F 7 /F 8 progenies derived from B × B crosses during the 2006 rainy season, of which 90 were
selected, with 23 of these flowering in 41−50 days and 53 flowering in 51−55 days (checks ICMB 94555 flowered
in 48 days, 842B in 46 days and 843B in 44 days). About 100 F 5 progenies derived from these crosses were also
evaluated during the summer season in drought nursery, of which 54 were selected. Of these, 20 flowered in 51−55
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