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| Maarten
van Ginkel (right, DDG Research) and lentil breeder Geletu Bejiga
review the experiment on lentil heat tolerance. |
Lentil is one of the world's more important
pulse crops, and a major source of dietary protein in West, South
and East Asia, as well as North and East Africa. Globally, lentil
area and production have increased in recent years (e.g. North America
and Australia), driven by export markets. However, production is expected
to fall in some traditional areas, particularly West Asia and North
Africa, due to poor rainfall and terminal drought and heat stress
which are becoming important due to climate change.
ICARDA's lentil scientists have developed a screening methodology
to evaluate large numbers of germplasm and breeding lines for tolerance
to heat. One important issue is to adjust sowing times to measure
the effect of heat stress at different growth stages, e.g. seedling
stage, flowering, grain-filling. Another is to disentangle the effects
of moisture stress and temperature stress. In one set of experiments
conducted at Tel Hadya during July-August 2008, 108 genotypes were
grown in shallow wooden containers filled with a mixture of soil and
sand. The plants were provided with adequate water, and thus experienced
only heat stress. Temperatures during July-August were in the range
of 37-45°C. Sensitive lines were killed when temperatures rose
beyond about 40°C. Beyond 45°C, very few lines survived. Those
that did will be tested further in the coming season. The methodology
has proved to be efficient and cost-effective, making it possible
to screen large numbers of genotypes, and identify lines tolerant
to heat at both seedling and flowering stages. Tolerant and susceptible
lines have been identified, and will be used as controls in future
experiments.
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