This al., 2009). On the base of presence

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This al., 2009). On the base of presence

          
                                                                                                             

This study was confined with anatomical
adaptation of three different grass species growing in different areas of Cholistan
desert. The soils were normal, saline and highly saline. Slected areas of
Cholistan desert were Baghdad-ul-jadeed (Islamia University of Bahawalpur),
Fort Derawar near Tehsil Ahmadpur east, Rohi (Qasim wala bangla) near Tehsil
Liaqatpur District Rahimyar khan. These plants are Cenchrus ciliaris L., Ochthocloa compressa,
Lasiurus scindicus.

The Cholistan desert comprise on an area of
more than 26,000 km2, where annual rainfall varies from 100 to 200
mm and the temperature usually progressed over 50 ºC in the hot days(Arshad et
al., 2008). Relative humidity is below 40% throughout the year. There is no
constant water source in the Cholistan Desert, and water table is very low with
average depth of about 40 m (Arshad et al., 2003; Arshad et al.,
2007; Ali et al., 2009).    

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On the base of presence of plants with respect to geography, the
Cholistan Desert can be divided into 7 different habitats, named as sand dunes,
inter-dune areas, salt-affected areas, brackish water vegetation, cultivated
land, border area, and man-made forest plantation at Lal-suhanra National Park
(Hameed et al., 2011).

Present study was accomplished to understand the adaptations of
halophytes present in Cholistan desert. Halophytic grasses present on saline
areas, which are comprised of Aeluropus
lagopoides, Cymbopogon jwarancusa, Ochthochloa compressa, Lasiurus scindicus,
Cenchrus ciliaris and Sporobolus
ioclados (Naz et al., 2009).Recently,
more than 19 grass species have been recorded from the Cholistan desert
(Hameed et al., 2011). 

The plants inhabiting desert environments face extreme adverse
conditions that square measure extraordinarily damaging to plant growth and
development (Arshad et al., 2008).

Extremely saline patches within the hot and arid Cholistan Desert
is a vital characteristic of this desert, and naturally custom-made plants
species to such nerve-racking conditions will give wonderful material for work
the adaptation mechanisms in respect to their growth and survival to counteract
high salinities (Ashraf, 2003).

Halophytes largely place confidence in the buildup of sufficient
ions in their tissues for osmoregulation and their survival depends on turning
away mechanism. Some species showed vital balance between growth and particle
accumulation by storing great deal of noxious ions within the cavum and so,
interference of those noxious salts to very important metabolic processes
avoided (Yasir et al., 2006; Li et al., 2008).

Plants
which are growing in Cholistan desert response to following major stresses,
i.e., Temperature stress, drought stress and salinity stress. Drought and
salinity are the major stress that is recorded as threats to variety of plant life;
agriculture crops yield production and nutrition needs (Hegazy et al. 2008).

 Plants have evolved a range of structural
diversifications to safeguard and scale back loss of water below drought
conditions (da Silva et al. 2003). Tissues facing the deficiency of
water typically show belittled cell size and inflated cell membrane thickness
(Hameed et al. 2012).

Grasses
that have the aptitude of drought tolerance have specific anatomical
modifications like inflated leaf and stratum thickness, belittled stomatal
space yet as density, smaller meta vascular tissue vessels (Nawazish et al.
2006; Hameed et al. 2012) and development of bulliform (Balsamo et
al. 2006; Hameed et al. 2009), mesophyll cells area unit largely
concerned in increasing appetisingness (thickness) and appetisingness is well
studied in dicots as compared to monocots, significantly just in case of
grasses (Flowers and Colmer 2008).

Moreover,
endodermis in stem or in roots may be a conjointly a distinguished characteristic
of plants growing in drought stress, which can play a crucial role in
preventing the stellar tissues desiccation and disintegration of root elements
(Balsamo et al. 2006; Naz et al. 2013).

Increased
soil salinity is one of the various devastating environmental adversaries that have
the multifaceted effects on plant growth and development (Flowers, 2004).
saline imposes each ionic and diffusion stresses on plants. This stress is
distinguished at many levels.

In salt
sensitive plants, shoot and to lesser extent root growth is for good reduced
inside hours of salt stress and this impact doesn’t seem to depend upon Na+
particle concentration within the young tissue (Munns, 2000).

A study
was conducted to judge the impact of salt stress on some ecologically totally
different Populations of 3 grasses viz.,Cymbopogon jwarancusa , Lasiurus
scindicus Henr., and Ochthochloa compressa from the Cholistan
desert. The populations of all 3 grasses from the extremely salt-affected
habitats were comparatively a lot of salt tolerant. Of the 3 grasses,
Ochthochloa compressa was the foremost tolerant because it was least
affected thanks to salt stress in terms of various growth attributes measured
within the gift study. Cymbopogon jwarancusa was moderately salt
tolerant, whereas Lasiurus scindicus was salt sensitive (Naz et al.
2009b).

There is
a large spectrum of salinity tolerance phenomena among higher plants (Robinson
et al., 1997), alongside genetic variability for salt tolerance, suggesting
that there’s the potential for enhancements to be created in these plants
(Allen et al., 1994).

 As a result of the strain tolerance responses
of all plants don’t seem to be identical; those with higher diversifications
(e.g., halophytes) are also studied in an effort to enhance the opposite
species. By mistreatment these plants as models, researchers ought to be
capable of raising the tolerance of non-halophytic plants. Growth and
development of plants area unit typically restricted by salinity. A typical
response of glycophytic plants is that the reduction in growth and chemical
change rates once subjected to saline conditions (Yang et al. 2009).

Mechanism
of salinity tolerance concerning stomatal structure and performance is
predicated on stability in chemical change rate, transpiration rate, lower
stomatal density and space, and sunken stomata (Liu et al., 2011; Saravanavel et
al. 2011; Orsini et al. 2012; Eisa et al. 2012).

Specific
anatomical and physiological modifications in plants exposed to salt-stressed
environments could alter them to thrive well on such environments. This
includes selective particle uptake (Flowers and Colmer 2008), accumulation of
venomous ions, partly in terms of inflated appetisingness (Hameed et al. 2009),
and excretion of such unwanted venomous ions (Ramadan and Flowers 2004, Naz et
al. 2009).

Adaptive
characteristics in plants for stress tolerance might evolve throughout the
course of evolution that has taken place over the long amount of your time
below the impact of high choice pressure. High salinities have a serious
influence on tracheophyte anatomical structures and these structural
modifications square measure decisive to combat nerve-racking saline conditions
(Grigore and Toma 2007).

Keeping
visible the particular modification in grasses for abiotic stress tolerance,
associate degree investigation are disbursed to analyze structural options that
square measure genetically fastened and change a grass species to deal with
harsh environmental conditions. On plants, and parameters like survival below
unfavorable conditions, plant height, leaf area, injury to salt stress,
relative rate of growth, and relative growth reduction square measure thought
of as choice criteria for salt tolerance (Ashraf & Harris, 2004).

The
ability of the plants to still grow would indicate a high level of salt
tolerance (Winicov, 1998). Salt tolerant plants will minimize the damaging
effects of high salinities by manufacturing a series of anatomical,
morphological and physiological variations (Poljakoff- Mayber, 1988), like an
intensive scheme (Hameed & Ashraf, 2008), reduction in growth in terms of
leaf space (Monteverdi et al., 2008) and salt secreting glands, and hairs on
the leaf surface (Marcum et al., 1998, Naz et al., 2009).

The tolerance level of plant to salt
stress could also be calculated from the plant survival rate and growth
maintenance that could be a variable character and controlled by several
factors. This variability in plant tolerance below salty conditions creates the
origination of glycophytes (salt sensitive) to halophytes (salt loving)
(Volkmar et al., 1998; Flowers et al., 2010).

The additional tolerant and productive
plant cultivars typically used over one mechanism to cope high salinities
(Cuartero et al., 2006) and also the necessary one is diffusion adjustment achieved
by accumulation of inorganic and organic ions (Singh et al., 2010). This
adjustment may occur at the cellular level by control particle fluxes through
cytomembrane (Shabala and Lew, 2002) and will be at whole plant level by
accumulation of inorganic ions like atomic number 11, K and Cl (Hariadi et al.,
2001).

 The osmoregulation is a crucial strategy
employed by plants to alter toxic salts and this can be done by accumulation of
the many organic molecules embrace glycine alkaloid, carbohydrates, amino acid
and free amino acids (Abdelmalek et al., 2011).

 These molecules not solely play a crucial role
within the diffusion adjustment, however conjointly act as associate degree
osmoprotective role in higher plants. These organic molecules area unit
accumulated in plant cells underneath high diffusion stress and thus, forestall
cellular injury by dehydration (Valentine, 1984).

 The plant species native to saline
environments showed important correlation of accumulated organic matter with
soil atomic number 11 gradients to beat the physiological drought (Hester et
al., 1996).

Three main and necessary mechanisms
utilized in plants that area unit growing as halophytes to stop these
mesophylls tissues from salt injury include: absorption of salts within the
vascular tissue areas at specific sites, development of dermal appendages (salt
organ and hairs), and appetizingness (Boursier et al., 1987; Huang and Steveninck,
1989).

The accommodative mechanisms at
structural and purposeful levels employed by plants to cope severe saline
conditions aren’t well self-addressed however. As a result, no distinct and
well-defined indicator accessible to explain the salinity tolerance in plants
which can facilitate the plant breeders to boost the tolerance capability of
agricultural crops (Ashraf and Harris, 2004).

The active mechanisms in operation in
plants for salt tolerance embody:

i)       dodging(restricted
up take of salts)

ii)      salt
accumulation (succulence),

iii)    compartmentalization
(salt accumulation vacuoles),

iv)     particle
property (discrimination in particle uptake),

v)      Diffusion
adjustment (accumulation of organic and inorganic molecules to take care of
diffusion potential) (Spychalla and Desborough, 1990; Begum and Karmoker,
1999).

. Salinity tolerance within the most
tolerant LS population relied on augmented root length and total leaf space,
restricted uptake of toxic Cl?, augmented uptake of Ca2+, high excretion of
Na+, accumulation of organic osmolytes, high water use potency, augmented root,
thicker leaf and area, intensive sclerification, giant metaxylem vessels, and
dense time of life on abaxial leaf surface. The BD population (from moderately
saline soil) relied on high Ca2+ uptake, Na+ excretion, cuticular thickness,
giant plant tissue cells, thick endodermis and huge plant tissue. The DF
population (from less saline soil) showed a big decrease all told morphological
characteristic; but, it accumulated organic osmolytes for its survival below
high salinities. Structural modifications all told 3 populations were crucial
for checking undue water loss below physiological stress that’s caused by high
amounts of soluble salts within the soil.(Naz et al ., 2014)

Though plant breeders could have
improved salinity tolerance of some crops plants by victimization growth
attributes because the main choice criteria, however, this choice becomes
additional practicable if the salt tolerance connected distinctive indicators
are known at the entire plant, tissue or cellular level. Thus, the requirement
to explore completely different underlying mechanisms of salinity tolerance by
characteristic the accommodative parts of salt tolerance at anatomical and
physiological levels becomes necessary to produce applicable indicators to
plant breeders (Hameed et al., 2010).

The studies proved that salt tolerance
could be a multigeneic regulated attribute not controlled by single factor and
create it a lot of sophisticated to check. Salt tolerant plant species have
confidence several methods at a time to cope with virulent effects of high
salinities (Niknam and McComb, 2000).

Aims and
Objectives

 

       
Main objectives of the present studies were:

1.      To analysis the structure and chemical
composition of selected soils.

2.      To get the information about adaptive
potential of the selected grasses from areas of Cholistan desert.

3.      To study the morph-anatomical
characteristics of the grasses.

4.      To make comparison between ecotypes of
the selected area.

5.      To use the concluded adaptive techniques
of plants to salinity response in various other agriculture purposes.

6.       To investigate potential anatomical indicators
that can be used for future research programmed.

 

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