Egypt crop growth development, productivity yield and quality,

Egypt is considered to be the largest importer country
for wheat worldwide. Wheat is the main part of the typical diet of the Egyptains.
The perdicatable  population in Egypt by 2050 will be between
115 and 179 million, a drop in rainfall and water decline are also predictable Boko
et al (2007). The consequences of water declination may result in limitation of
the crop production and expansion in land reclamization.

Water inadequacy in  arid and semi-arid regions effect crop growth development,
productivity yield
and quality, in
addition water
deficiency found to be affecting expression of genes in plant development
and  growth, (Yang 2004; Shi et al 2008,
2009; Galle et al.,
2007). Water stress tolerance is the ability of a plant to grow, live,
and reproduce acceptably with limited water supply or during water deficit through
different periods during the  production
season (Turner, 1979).

The speed  of  seed germination may delayed if farmers plant wheat
seeds under insufficient amount of rainfall condition or irrigated water. Delay
in gerimination may lead also to  another
problem  which is  the infection with pathogens, and the missing
spots will appear in the field with the destabilized plants. However

Seed germination and early seedling growth are actually the
most serious times in plant development during water stress, seed
germination can be  completely stopped
because of  drought (Ahmad et al., 2009;  Yang et.al. 2016). The response of plant during water stress
conditions  have become an important
research topic particularly in regions affected by water stress. Seedling
development and seed germination can be used in testing and selection
criteria  for identifying drought
tolerant crop genotypes. Investigations concerning water deficiency during
plant production in their growing seasons  usually include seed germination in osmoticum
(ASHRAF & ABU-SHAKRA 1978; BASSIRI et al., 1977 ; JOHNSON & ASAY, 1978
; Blum et.al. 1980). and seedling growth or survival under conditions of
induced moisture deficit YOUNIS et al., 1963). Blum et.al. 1980 postulated that
genotypic tolerance to mositure stress is specific bioprocess, concerning  the level of endosperm utilization,  germination rate, seedling growth through  water stress and seedling recovery after
water stress. Differences
among wheat cultivars in germination characters and seedling parameters were
reported in various studies (Kandil  et
al 2012, Sadat  and McNeilly 2000, El-Hendawy  et
al 2005).

Plants genoypes of same
species in  nature have different  genetic make up, these variability
occured  among members of same species  makes some of these genotypes more tolerant
to biotic or abiotic stresses under the same degree of stress. Screening for
drought tolerance or any other biotic or abiotic stress is essential for
improveming tolerance to different stress. The use of suitable techniques for
measuring stress tolerance is very important. (Mitcell et al., 1998). One approach to define drought tolerant
cultivars at emergence stage is to estimate germination of  different wheat genotypes germination under
low soil moisture levels that would be found in semi-arid soils. One simple protocol used to
detect water stress as a limiting factor for seed germination is to construct the moisture retention curve,
and to select soil moisture stressful level (Brady and Weil, 2010). , wheat crop is one of the few plants that able to evolve and
start germination at an adequate degree in environments of soil water potential
that  lower than -1500 kPa (Lindstrom et.
al, 1976).   

For
speed up wheat improvement programs, marker-assisted selection (MAS) can be a good tool and fulfill strategy which
can fascilitate screening  germplasm  of many crops for thousands of genomic
regions under water stress condition, which was, not possible  in the past (Ashraf, 2010).

 

The
objectives of the present study are: (1) screening the response of some
Egyptain wheat cultivars for seed germination under water stress levels (2) verification
for the presence of drought resistant genes in the studied Egyptain cultivars
using specific molecular markers for drought.