Chickpea and temperature stress: An overview - Legumes Under Environmental Stress: Yield, Improvement and Adaptations - page 86

concentration increased in chickpea but the accumulation
of storage proteins, starch and several amino acids
decreased. However, the effect was influenced by the
stage of seed development. There was a greater reduction
of starch, proteins, soluble sugars, fat, crude fibre and
storage protein fractions when cold stress occurred in
late pod-filling compared to early pod-filling stages (Kaur
et al., 2008). However, seed germination was inhibited
when plants were stressed at early pod-filling.
The effects of high temperature stress were generally
similar to cold stress. High sucrose synthase and low
invertase activity were observed in the seeds of heat-
tolerant genotypes compared with heat-sensitive types
during early pod filling (Chickpea Technical Report,
2011). Generally, high temperature during grain filling
reduces dough and baking quality in grain crops (Stone &
Nicolas, 1994). However, the available information on
grain quality under temperature stresses in chickpea is
limited. There is clearly a need to extend our knowledge
of grain quality including baking quality under both
high and low temperature stresses.

germplasm at ICRISAT and several other locations in
India (Gaur et al., 2013, 2014).
A few heat-tolerant chickpea cultivars (ICCV 88512
and ICCV 513) were identified more than a decade ago
(Dua, 2001). However, heat tolerance research in
chickpea has only received significant attention in
recent years. More recently, Krishnamurthy et al. (2011)
identified 18 stable heat-tolerant genotypes (e.g. ICC
1205, ICC 637 and ICC 15618) by field screening a ref-
erence set of chickpea from southern and central Indian
field trials. Short-duration, high-yielding, heat-tolerant
genotypes (ICC 5597, ICC 5829, ICC 6121, ICC 7410,
ICC 11916, ICC 13124, ICC 14284, ICC 14368 and ICC
14653) were identified by Upadhyaya et al. (2011). A
heat-tolerant breeding line, ICCV 92944, has been
released in Myanmar (as Yezin 6) and in India (as JG
14) and is performing well under late-sown conditions
(Gaur et al., 2013). Several breeding lines with higher
yields under heat stress than the standard cultivar ICCV
929944 have been identified (Gaur et al., 2013, 2014).
Outside India, Kaloki (2010) identified ICCV 92318 as a
source of heat tolerance in the semi-arid environments
of Kenya through the African Climate Change Breeding
Program.
Devasirvatham et al. (2012b) confirmed the heat tol-
erance of ICCV 92944 using a pollen selection method.
Devasirvatham et al. (2013) also confirmed the heat tol-
erance of germplasm identified earlier by Krishnamurthy
et al. (2011) (ICC 1205, ICC 15614) using pollen via-
bility in the field and controlled environment studies,
and suggested using this technique to develop heat-
tolerant cultivars. These materials have been
incorporated into chickpea improvement at ICRISAT
and new heat-tolerant progeny are under development
as genetic mapping populations (Gaur et al., 2013).
Diversity arrays technology (DArT) (Mace et al., 2008)
markers with good genome coverage were associated
with traits targeted for high temperature tolerance
in chickpea, and many genomic regions linked with
phenology and grain yield have been identified
(Devasirvatham, 2012), thus demonstrating the feasi-
bility of applying genetic association analysis to explore
complex traits in future. While there is clearly significant
variation for high temperature tolerance in adapted
chickpea, there is a compelling need to extend the
search for new genetic diversity to provide additional
allelic variation for temperature tolerance. The wild
annual Cicer sp. is a possible source of variation and

5.4 Breeding for tolerance
to temperature stresses

Chickpea improvement has focused on yield potential
and regional adaptation through resistance and toler-
ance to abiotic and biotic stresses, plant type and grain
characteristics. At present, the selected bulk method
is the most common selection technique used in
chickpea breeding (Gaur et al., 2007). The selected
bulk method is relatively inexpensive to employ and
the response to selection is generally not inferior to
more labour-intensive methods such as pedigree
selection (Salimath et al., 2007). This section describes
some of the breeding strategies used to improve tem-
perature tolerance in chickpea and explores options
for future breeding.

5.4.1 high temperature tolerance
A simple but effective field screening technique for
heat tolerance at the reproductive stage in chickpea
has been developed at ICRISAT (Gaur et al., 2013,
2014). It involves advancing sowing date to synchro-
nize the reproductive phase of the crop with the
occurrence of higher temperatures (≥35°C). This
method was effective in identifying heat-tolerant