Agriculture Reference
In-Depth Information
System for Drought Phenotyping), rewaters individual soil columns
according to the degree of evapotranspiration and the stress treatment
applied. Field drought phenotyping is also conducted during the off
(dry)-season at the Porangatu (Goiás, Brazil) experimental station
offering control of timing, intensity, and duration of the drought period
and avoiding the climatic uncertainty associated with trials during the
main season. Low-P screening is performed at Embrapa in a
field that
has never been fertilized and where phosphorus levels in the soil are
very low. Trials are conducted under low phosphorus as well as with
normal fertilization treatments. Embrapa is also using sites with a
high concentration of iron to screen and evaluate elite lines for iron
toxicity tolerance.
With the strong collaboration with NARES partners in Colombia and
Brazil, as well as the numerous members of FLAR, research is under
way to map potential hot spots for a variety of abiotic stresses.
Screening Methods.
Exploiting current high-throughput phenotyping
tools, the CIAT phenotyping team is focusing on
field-based methodol-
ogies with emphasis on remote-sensing techniques designed to assess
plant performance in a fast and nondestructive manner. CIAT and
FLAR have responded to these challenges by developing an inter-
disciplinary team focused on speci
c high-priority stresses such as
drought, heat, cold, and N use ef
ciency. New screening techniques
such as infrared (IR) and digital imaging have been used to screen
germplasm/populations to discover elite lines with novel stress-
tolerance mechanisms. To evaluate responses to drought, phenotyping
is performed with digital thermographic IR imaging to screen for
canopy temperature. This measurement is then normalized to present
the crop water stress index accounting for the environmental (soil and
climate) conditions, and to give an estimate of plant transpiration
capacity (Audebert et al. 2013).
In addition to
field screening methods, CIAT has a built-in facility to
conduct extensive root screening in the greenhouse. Other medium-
throughput innovative methods such as root basket screening (Uga et al.
2011, 2013) have been effectively used to detect root angle variation in
rice cultivars. This method maintains the shallow and deep orientation
of roots, thus enabling the sequential screening of root angle and the ratio
of deeper roots, either manually or using suitable software. Research
networks with partners continue to be important for root and image
studies and for understanding and screening in target environments.
At Embrapa, evaluations for adaptation to drought involve
field trials
and the SBIR/STTR Interactive Topic Information System (SITIS)
