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

Milestones: Molecular markers for additional QTLs for drought avoidance root traits identified (PMG/JK/LK/RKV)
2007
Evaluation of new RIL populations for phenology, yield, and yield contributing traits: Two new RIL
populations (ICC 283 x ICC 8261 and ICC 4958 x ICC 1882) developed for mapping of additional QTLs for
drought avoidance root traits were evaluated for phenology, yield, and yield traits. A total of 281 F 8 RILs of ICC
283 x ICC 8261 and 264 F 8 RILs of ICC 4958 x ICC 1882 were evaluated in an augmented design along with the
parental lines. Both populations exhibited a wide range of variability for all traits studied (Table 3). Over 120 RILs
of ICC 283 x ICC 8261 gave 10 to 96% higher yield than the drought tolerant parent ICC 8261, while 25 RILs of
ICC 4958 x ICC 1882 gave 10 to 26% higher yield than the higher yielding drought tolerant parent ICC 4958. A
RIL population of ICC 4958 x ICC 1882 has been phenotyped using tall cylinder (120cm height) culture systems in
3 replications in 2005 post-rainy season. The substantial variation was observed in root length density, rot dry
weight and rooting depth between the parental lines, and the RILs showed normal distribution on these root traits. In
ICC 283 x ICC 8231, the phenotyping has been completed in 2006 post-rainy season, and analysis is going on.
These populations are being phenotyped for root traits and genotyped using polymorphic SSR markers.
Table 3. Variability for different traits in two new RIL mapping populations developed for mapping of
drought avoidance root QTLs.
ICC 283 x ICC 8261 RIL population ICC 4958 x ICC 1882 RIL population
ICC 283 ICC 8261 ICC 283 x
ICC 8261
RILs
ICC 4958 ICC 1882 ICC 4958 x
ICC 1882
RILs
Days to 50% 60 58 45-88 50 54 42-66
flowering
Days to maturity 125 126 108-140 116 110 105-119
Plant height (cm) 35.0 56.0 30.0-64.0 43.7 39.3 26.0-56.3
Plant width (cm) 12.7 18.3 9.0-53.7 18.0 26.7 13.3-44.3
No, of primary 2.7 3.3 1.7-6.7 2.3 3.0 1.3-4.3
branches per plant
No. of secondary 2.0 3.0 1.0-11.7 3.0 4.7 1.3-6.3
branches per plant
No. of pods per plant 92 37 24-220 41 135 26-238
100-seed weight (g) 16.2 32.2 10.3-33.1 39.4 13.7 13.4-35.3
Biomass (kg ha -1 ) 1996 3013 1146-4413 3158 2650 479-4443
Seed yield
1036 1095 356-2148 1820 1453 270-2476
(kg ha -1 )
Harvest index (%) 51.9 36.3 24.6-60.0 57.6 54.8 24.6-66.2
PM Gaur and J Kashiwagi
Milestones: QTLs for drought avoidance root traits validated (PMG/JK/LK/RKV) 2009
This milestone is linked to the progress reported above, and one population will be used for mapping, and another
for validation of QTLs.
Milestones: MABC-derived drought tolerant lines available from 2-3 locally adapted cultivars (PMG/JK/LK/RKV)
2011
Initiation of MABC for introgression of drought avoidance root traits in farmer-preferred cultivars: We
identified three farmer-preferred cultivars, JG 11 in Desi type and Chefe (ICCV 92318) and KAK 2 (ICCV 92311)
in Kabuli type for introgression of large root traits (high root length and high root depth density) from ICC 8261
(Kabuli) and ICC 4958 (Desi) using marker-assisted backcrossing (MABC). Six crosses (JG 11 X ICC 8261, KAK 2
X ICC 8261, Chefe X ICC 8261, JG 11 X ICC 4958, KAK 2 X ICC 4958, Chefe X ICC 4958) were made during
2006 in the greenhouse. The F 1 s from these crosses are being grown during the post-rainy season 2006/07 along
with parents for making backcrosses with the parental cultivars.
PM Gaur, J Kashiwagi and Rajeev Varshney
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