🍀HOME GARDEN🍀 Author:- G.keerthana

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