STRATAGIES TO IMPROVE YIELD AND NUTRITIONAL QUALITY UNDER
ABIOTIC STRESS
Abiotic
stress is
defined as the negative impact of non living factors on the living organisms in a specific
environment.
ü Abiotic stress factors, or stressors,
are naturally occurring, often intangible, factors such as intense
sunlight or wind that may cause harm to the plants and animals in the area
affected.
ü Abiotic stress is essentially unavoidable.
ü Abiotic stress is the most harmful
factor concerning the growth and productivity of crops world wide.
ABIOTC
FACTORS
Crop Production as Affected Abiotic Stresses
However, it is generally believed that abiotic stresses are considered to
be the main source of yield reduction.
The estimated potential yield losses are-
Ø 17% due to drought,
Ø 20% due to salinity,
Ø 40% due to high temperature,
Ø 15% due to low temperature and
Ø 8% by other factors (Rehman et al.
2005; Ashraf et al. 2008).
Crop Improvement Against Salinity and Drought Stress:
Abiotic stresses are the major factors of poverty for
millions of people.
ü In this scenario, it is widely urged
that strategies should be adopted which may be used to get maximum crop stand
and economic returns from stressful environments.
Major strategies
• Breeding of new crop varieties.
• Screening and selection of the
existing germplasm of potential crops.
• Production of genetically modified
(GM) crops,
• Exogenous use of osmoprotectants.
Objectives
• Both water stress and salt stress
occur naturally in habitats where temperature is high.
• Both water stress and salt stress
affected more than 10% of arable land, which results in rapid increase in
desertification and salinization world-wide. As a consequence,
• Average yields of major crops reduced
by more than 50%.
Due to this reason,
• there is an increasing demand for new
plant cultivars that have a potential for higher yield under such abiotic
adversaries.
• there are high expectations that
plant breeders will certainly provide salt tolerant crops with higher yield.
BREEDING METHODS FOR ABIOTIC STRESS RESISTANCE
In case of self pollinated crops
-Introduction
-Pure line selection
-Mass selection
-Hybridization
-Mutation breeding
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