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

in both groups. Among the genotypes evaluated, desi genotypes had higher salinity tolerance than kabuli
genotypes. A strong relationship was found between the seed yield under salinity and the seed yield under a
non-saline control treatment, indicating that the seed yield under salinity was explained in part by a yield
potential component and in part by salinity tolerance per se. Seed yields under salinity were therefore computed
to separate the yield potential component from the residuals that accounted for salinity tolerance per se. The
residuals were highly correlated to the ratio of seed yield under salinity to that of the control, indicating that
both parameters can be used to assess salinity tolerance. A similar ratio was calculated for shoot dry weight at
50 days after sowing. However, no significant correlation was found between the shoot dry weight ratio and the
yield ratio, indicating that differences in salinity tolerance among genotypes could not be inferred from
measurements in the vegetative stage. The major trait related to salinity tolerance was the ability to maintain a
large number of filled pods, whereas seed size was similar in tolerant and sensitive genotypes. Salinity tolerance
was also not related to the Na + or K + concentrations in the shoot. A journal article has been submitted to the
field crops Research.
V Vadez, L Krishnamurthy and HD Upadhyaya
Milestone C.5.2.3: Sorghum mini core and pearl millet reference set screened for salinity tolerance
(VV/LK/HDU/CTH/KNR, 2008)
First screening of a part of the mini-core collection of sorghum has been initiated (October 2006) and data will
be available in 2007. The full collection should be screened in 2007-08.
V Vadez, L Krishnamurthy, HD Upadhyaya, CT Hash and KN Rai
Milestone C.5.2.4: Reference sets of chickpea, pigeonpea, and groundnut evaluated for salinity
(VV/LK/HDU/RKV, 2010)
Activity C.5.3: Evaluate groundnut and sorghum mini core and/or reference sets for transpiration
efficiency (TE) and root traits
Milestone C.5.3.1: Groundnut mini-core set screened for TE (VV/HDU/RKV/CLLG, 2008)
We have screened 440 groundnut genotypes for TE, under progressive soil drying conditions, during the Feb-
April 2006 period. These 440 genotypes included the mini core collection of groundnut (184 accessions), other
germplasm lines, control cultivars, and elite breeding lines. The data show an impressive range of variation
between the top and the bottom ranked groundnut genotypes for transpiration efficiency (TE, g kg -1 water
transpired). In that experiment, TE varied between about 0.3 g kg -1 water transpired and 3.6 g kg -1 water
transpired. About 90% of the genotypes (excluding the bottom 40 and top 10 in the ranking of TE) were in a
range of TE between 0.5 and 2.5 g kg -1 water transpired, i.e. still a 5-fold range of variation. Ten genotypes had
TE higher than 2.5 g kg -1 water transpired and one genotype reached 3.6 g kg -1 water transpired. A repeat of that
experiment will be carried out in 2007. TE was also assessed under well-watered (WW) conditions in the mini
core collection of groundnut, plus with controls (200 accessions). It has been reported in the literature that there
is a good relation between TE measured under water stress and TE measured under well-watered conditions,
from which it has been inferred that mesophyll efficiency differences were the major reason for differences in
TE. However, this relation has been worked out with a very narrow range of genotypes and fully overlooks the
potential role of stomatal regulation in the determination of TE differences. Relation between TE under water
stress (WS) and under well-watered conditions with a larger set of genotype was also assessed. TE was overall
higher under WW conditions (1.92 g kg -1 water transpired) than under WS (1.44 g kg -1 water transpired). We
found significant relation between TE under water stress and TE under well-watered conditions. However, the
correlation coefficient was 0.32 only, indicating that it would be advisable to consider TE under WS and WW
conditions separately. Analysis needs to be done to test the significance of genotype x moisture interaction.
V Vadez, L Krishnamurthy, HD Upadhyaya,
RK Varshney, and, CL.L Gowda
Milestone C.5.3.2: Sorghum mini-core (or reference) set screened for TE (VV/HDU/CTH/BVSR, 2009)
Milestone C.5.3.3: Groundnut mini-core screened for root traits (VV/HDU/RKV/CLLG, 2010)
The protocol to screen groundnut for root traits is being worked out with a small set of genotypes to optimize
the cylinder system that will be used. Screening for root traits in groundnut will be based both on transpiration
values (using a lysimetric system) and on root parameters (max depth, length density at different depth).
V Vadez, HD Upadhyaya, RK Varshney and CLL Gowda
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