Chickpea and temperature stress: An overview - Legumes Under Environmental Stress: Yield, Improvement and Adaptations - page 87

could be exploited. This new allelic variation would
allow plant breeders to lift the current reproductive
temperature limits on chickpea.

5.5 Conclusions

Both high and low temperature stresses cause grain
yield loss. Cold stress encourages a prolonged vegetative
period while high temperatures reduce the duration of
the vegetative period. Reduced pollen viability and
pollen germination on the stigma are the primary causes
of poor pod set in chickpea following low temperature
stress. Similarly, high temperature stress disrupts pollen
viability and anther dehiscence. However, stigma recep-
tivity is not affected by either stress. The rate and
duration of seed filling are both decreased by cold and
high temperature stresses.
Recent chickpea breeding programmes targeting both
high and low temperature stresses have been initiated
by many countries including India, Australia and
Canada, with global centres such as ICARDA and
ICRISAT supporting the wider effort through the char-
acterization and exploitation of genetic resources.
Screening for tolerance to temperature stresses has
identified many promising sources of tolerance to both
high and low temperature in chickpea. However, field-
based screening is generally based on delayed sowing,
and biomass development and the length of the vegeta-
tive phase are reduced in such treatments, thus reducing
the fitness of plants to survive temperature extremes at
flowering. Field-based methods that impose a tempera-
ture stress on a normally grown plant should be
developed to confirm and validate the response of
chickpea lines already identified. The identification of
QTLs for temperature stress tolerance and linked molec-
ular markers will undoubtedly improve rates of genetic
advance and marker-assisted selection can easily be
incorporated into most breeding methods.
Rapid progress has been made in the development of
genomic resources for chickpea, and breeders have
already started integrating molecular breeding strategies
such as marker-assisted backcrossing (MABC) and
marker-assisted recurrent selection (MARS) to improving
drought tolerance in chickpea (Gaur et al., 2012). Advances
in marker systems and genotyping technologies such as
DArT and single nucleotide polymorphisms (SNPs) and
genotyping by sequencing (GBS) have made genotyping
large numbers of materials cost efficient. The integration
of genomic technologies in chickpea breeding will greatly
improve efficiency of developing chickpea cultivars that
are more resilient to changes in temperature. For example,
MARS recombines significant gene effects found among

5.4.2 Low temperature tolerance
Low temperature stress breeding generally aims to
develop materials adapted to the temperature range
−1.5 to 15°C at the reproductive stage and less than
−1.5°C at the vegetative growth (Croser et al., 2003).
Different sources of resistance to cold tolerance are
reported by Chaturvedi et al. (2009), and several cold-
tolerant breeding lines such as ICCVs 88502, 88503,
88506, 88510 and 88516 have been developed that
set pods at less than 15°C in India (ICRISAT, 1994).
The Indian Agricultural Research Institute (IARI) has
also developed a few cold-tolerant genotypes (BGD
112 green, BG 1100, BG 1101, PUSA 1103, BGD 1005,
PUSA 1108, DG 5025, DG 5027, DG 5028, DG 5036
and DG 5042) (Gaur et al., 2007). Using pollen as a
selection method, Clarke et al. (2004) confirmed the
cold tolerance of ICCV 88516 and 88510 and the sen-
sitivity of Amethyst, Dooen, Tyson and FLIP84-15C in
Western Australia. Accessions of cultivated and wild
Cicer sp. were screened for cold tolerance at ICARDA
(Singh et al., 1995). These authors reported cold
tolerance in the lines ILC 8262, ILC 8617 (a mutant)
and a FLIP 97-82C from cultivated Cicer along with
wild annual chickpea such as C . bijugum and C .
reticulatum .
Later, Toker (2005) identified chilling tolerance
(<−1.5°C) in annual wild Cicer sp. of yamashitae .
Heidarvand et al. (2011) identified the genotypes Sel
95Th1716 and Sel 96Th11439 as chilling tolerant based
on field screening at the vegetative stage where plants
were exposed to −11°C to −25°C at the Dryland
Agriculture Research Institute (DARI) of Iran.
Both additive and non-additive gene effects govern
cold tolerance in chickpea. Cold tolerance was observed
to be dominant over susceptibility for at least five sets of
genes (Malhotra & Singh, 1990). Breeding at ICARDA
has resulted in the expansion of genetic variability for
flowering at low temperatures using cultivated × wild
Cicer crosses. The genes responsible for flowering at low
temperature have been transferred from wild to culti-
vated lines (Chaturvedi et al., 2009). These reports
suggested that wild relatives of chickpea can be used as
a source of tolerance to low temperatures in applied
breeding.