Legumes and breeding under abiotic stress: An overview - Legumes Under Environmental Stress: Yield, Improvement and Adaptations - page 6

Semi-Arid Tropics (ICRISAT) in India, supported by the
Consultative Group in International Agricultural
Research (CGIAR), as well as through strengthening of
the agricultural research systems of different conditions
(Materne et al., 2011). Genetic resources for use in cool
season food legume breeding are maintained at
ICARDA, ICRISAT and also by other national pro-
grammes, particularly in the USA, Canada, Australia,
India and a number of other important repositories
(Materne et al., 2011).

was recently reported that subsoil chloride (Cl)
concentration was the most effective indicator of reduced
grain yields rather than salinity, and that growing
chickpea on soils with Cl > 600 mg/kg should be avoided
due to high yield losses (Dang et al., 2010). Similarly,
faba bean has been reported to be more sensitive to Cl
than Na, and genetic variation for tolerance to the
individual ions was observed (Tavakkoli et al., 2010).
Screening methodologies range from pot-based to field
methods. More recently, attention has been focused on
improving genetic knowledge that could provide molec-
ular markers for salt tolerance in the near future
(Varshney et al., 2009).
Cold tolerance has been an important trait for
improvement in crop adaptation in many countries
(Materne et al., 2011). For chickpea, chilling tempera-
tures at the reproductive phase often result in pod
abortion. Clarke et al. (2004) successfully used pollen
selection methods to develop and release two cultivars
that produce pods under lower temperatures than other
cultivars. In the USA and Turkey, large yield increases
have been achieved by sowing lentil in winter rather
than spring, using genotypes tolerant to cold tempera-
tures during winter (Materne & McNeil, 2007).
Similarly, very high tolerance of seedlings to cold tem-
peratures has been identified in faba bean (Link et al.,
2010). In Australia, lentil breeding lines with improved
tolerance to boron have been developed that could
improve yields by up to 91% in the target region, based
on controlled environment experiments (Hobson et al.,
2006). Whilst genetic variation has been identified in
chickpea (Hobson et al., 2009), only limited research in
this crop has been undertaken. Genetic variation has
been identified in field pea (Redden et al., 2005), and the
overall level of tolerance of this crop is greater than in
lentil and chickpea (Materne et al., 2011).

1.4 Breeding of cool season food
legumes under abiotic stress

Legumes are considered more sensitive than cereals to a
wide range of abiotic stresses (Dita et al., 2006). Materne
et al. (2011) reported that matching a crop's phenology
to an environment, including the avoidance of drought
and heat, is a key part of improving adaptation and
increasing crop yields, and has been a major global focus
in breeding for local and broad adaptation of all the cool
season food legumes (Materne & Siddique, 2009; Khan
et al., 2010). One of the major achievements of ICARDA's
collaborative lentil research is broadening the narrow
genetic base of lentil in South Asia through introgres-
sion of genes from ICARDA germplasm (Materne et al.,
2011).
In short growing season climates (both winter- and
spring-sown crops), selection for earlier flowering geno-
types has been an important trait for avoidance of late
season abiotic stress (e.g. terminal drought and high
temperatures) (Materne et al., 2011). In chickpea, whilst
the Kabuli type is generally considered more drought
sensitive than Desi types (Leport et al., 2006), ICRISAT
developed an extra-short-duration Kabuli variety (ICCV
2), which improved yields and expanded production.
Since the release of this cultivar, even earlier-maturing
germplasm has been developed and combined with a
double-podding trait (Ahmad et al., 2005).
Salinity is attracting greater attention from researchers
and breeding programmes internationally (Materne
et al., 2011). Lentil cultivars with improved tolerance to
NaCl have been released already in Australia (Materne &
Siddique, 2009). Flowers et al. (2010) give a comprehen-
sive overview of studies conducted to explore genetic
variation to salt sensitivity in chickpea. Greater efforts
have also been focused on quantifying thresholds, and it

1.5 Breeding of warm season food
legumes

Singh et al. (2011) reported that efforts focused on the
breeding of warm season food legumes have been made
in different international centres supported by CGIAR.
Among these centres, ICRISAT has focused research on
pigeon pea, and the International Institute of Tropical
Agriculture (IITA) has a global mandate for cowpea
improvement. The Asian Vegetable Research and