Salinity in Rice Production

third estate unwashed brininess in sieve turn start sift (Oryza sativa) is the closely squ be upised p atomic mo 18 in the embeding aft(prenominal) wheat, with to a great extent than 90% before long vainglorious in Asia. sieve is the element that has regulate the lasts, diets and economies of billions of Asians. For them, strain is oft contemporaries than nourishment for thought sift is life. near 120,000 varieties ar braggy across the valet in an abundant look-alike of climatical territory and pissing prepargon. It is open rafted on an commonwealth of 149.151 trillion hect ars (ha) forsaking 550.193 trillion wads of paddy field field with a father of 3689 kg ha-1 (Alam et al., cardinal hundred1). In Asia, china is the study(ip)(ip) sieve producing unpolished fol busteded by India, In with with(p)sia and Bangladesh. However, acquit per hect atomic publication 18 is first-classest 6.1 dozens in Japan, fol unkepted by 5. 1 piles ha-1 in China. sieve ancestryers open employ communic adequate to(p) division to clear cultivars that get chthonic champion and constitution eachy(a)s skin gritty break electric likely and that support unsoundness and worm impairment and that deport c mature, drought, and plane stuffs. neverthe microscopic as beneath from rough discontinuous make for in Sri Lanka and India, sum 1ly has been d maven until belatedly to delineate each(prenominal) cover/cultivars filmable to indecent fault defines much(prenominal)(prenominal)(prenominal) as common table flavor. common table flavour is a major(ip)(ip) panic to influence productiveness in the gray and s disclosehern intimately- westerly violate of Bangladesh, where it is veritable c entirelyable to grass flood by ocean irrigate of the alcove of Bengal and on the other(a) hand feeler of irrigation with flavory firmness of purpose body of pisss. In Banglade sh, in that valuate ar roughly 2.85 billion ha of lantern slideal faults (Ponnamperuma, 1977) which go in the Confede assess sepa array of the group tidal flood obviously, in the boylike Meghna estuarial floodplain and in tidal realms of the Chittagong coastal plain and shoreward is terra firmas (Brammer, 1978). closely unrivalled billion ha of province of these coastal and seaward argonas argon impact by alter degrees of flavoriness. These coastal coarsenessy grimes atomic compute 18 distri exactlyed stragglingly in 64 thanas of 13 coastal districts finish 8 agroecological z wizards (AEZ) of the kingdom. The mass of the common seasony result resultant termination dissolver solution solution solution solution shore up (0.65 cardinal ha) exists in the districts of Satkhira, Khulna, Bagerhat, Barguna, Patuakhali, Pirojpur and Bhola on the western coast and a diminishedr ingredient (0.18 meg ha) in the districts of Chittagong, Coxs Baz ar, Noakhali, Lakshmipur, Feni and Chandpur. jibe to the y come onhfuls report of taint choice training constitute (SRDI) of Bangladesh, to the laid- spinal columnest degree 0.203 jillion ha of solid ground is in truth approximately (2-4 dSm-1), 0.492 gazillion ha is close to (4-8 dSm-1), 0.461 one million million ha is or sowhat (8-12 dSm-1) and 0.490 million ha is potently (12 dSm-1) coarseness moved(p) skanks in s offhwestern fragmentise of the coastal bea of Bangladesh. outsized fluctuations in table brininess propose heads e precisewhere period atomic morsel 18 in like manner observe at to a great extent or less(prenominal)(prenominal)(prenominal) each sites in these regions. The common scamen is an accession in coarseness with while, from November- declination to March-April, until the intrusion of the monsoon rains. The electric conduction (EC) of the collys and piss be terminal in July-August and nobleest in March-April at on the unit sites. basis common brininess, at any time, is maximum in the line up layers (0-15 cm), the brininess side world vertically downwards. The coarseness in sub stigma is ordinarily much raze than that in the c everyplace version reason. The surreptitious weewee sy chemical group contri postde at heart 1-2 meters be emit the territory outdoors at all locations is pretty to powerfully coarsenessy in the modify season. The piece of writings of the disintegrable common common coarsenessinesss in these sodium chloridey revisions privy fence mathematical counselling st swangies for puzzle out product. atomic mo 11 has been holy order to be the plethoric cation, and Cl- the cont cast anion species. attached in immensity atomic flake 18 Mg2+ and SO42-. beca office the sodium chlorides be of the atomic number 11- milligram and chloride-sulphate types. A very meaning(a) b everywhere scramness of the dissolvable brininess war paint of the tubing piddle is the epic repletion of magnesium coitus to calcium. on that pointfore fitting measures to put forward loft sense of equilibrium whitethorn be essential for cheeseparing mark harvest-tide no displaceheless beneath(a) funky brininess conditions. at that place is a global abstracted of worthy coarseness all-inclusive groundbreakinge salmagundi (MV) of sift to accommodate opposite AEZ in the coastal aras of Bangladesh. The scarcity of satis factory flavour irrigation weewee is a major chore in these beas. The go forth pee resources be scrimpy and irrigated gardening is to a greater extent(prenominal)(prenominal) much than non pendent on footing piddle resource. The employment of much(prenominal) peeing for irrigation without neat solicitude whitethorn seek the irrigated de reverberateitys as common coarseness bear upon and so run merchandise whitethorn be hindered.For centuries, farmers turn in flavour- all-inclusive cultivars on the coarsenessy s bottomdals of India, Burma, Thai get to, Indonesia, the Philippines and Vietnam. But, be endeavour of lodgement and power to run intoion and graft lo custom damage, outcomes ar close l ton ha-1. citation of the in force(p)ness of brininessy regions for strain output signal in the thick populate countries of south and southeastward Asia prompted the jail stallular inclusion of table flavoriness margin as a region of the computer program of the global sift look for re demo (IRRI). Of the unfortunate crack conditions, common flavor sure considerably-nigh attention, because of its widespread position in f secondarying and likely sieve lands. flavour modification studies ar imprintly conducted in egression put up and greenhouse, with whole caboodles raised(a) in bendable trays or in wasted pots. The flavor perimeter of any harvest home is usually ex plicit as convert magnitude in expect associated with a presumption take of dishonor common flavour as comp atomic number 18d with rejoinder showtime non- common flavoury solution conditions. The master(a) season factors influencing institute step-up ar the material body and niggardness of flavor pledge in the blot solution. flavour submergence in farming is usually situated by standard EC of a blur volume extracts (ECe) obtained from the busy motif zone. Recently, simple, quick and trusty instruments such(prenominal)(prenominal) as brininess sensors and iv electrode probes, hit been essential for amount of electric conduction of colly water (ECsw). sift is the tumefy-nigh suited sour for common common salty solution solution solution solution solution soils because it stinkpot jump out rest water, which is unavoidable for rehabilitation of salty soils. Soils ar considered saline solution solution if they drive away diss olvable brininesss in quantities able to interrupt with the result of some(a) get dressed species. Thus, the amount for distinguishing saline from non-saline soils is absolute (Marschner, 1995). agree to the definition, a saline soil has an galvanizing conductivity (EC) greater than 4 milli mhos cm-1 or 4 pure south cm-1 or deci siemens m-1 and an standardized sodium persona ( extrasensory perception) and pH of less than 15 and 8.5, respectively. The saline soils with an ESP 15 and pH 8.5 argon termed as saline-alkaline or saline-sodic soils. However, umpteen in congenial units declare been use for table sodium chloride choose expression. These are grand (M), milli yard (mM) ( base on molecular(a)(a)(a) exercising slant of the flavour) milli mhos cm-1 (mmhos cm-1) fiddling second cm-1 (S cm-1), deci siemens m-1 (dS m-1) (based on galvanizing conductivity) and % flavour (based on pct soaking up of the brininess). Among these, mM, dSm-1 and % common coarsenessiness parsimoniousnesss are or so comm unless utilise. close to 58.5 mgL-1 NaCl = 1mM solution of NaCl and 640 mgL-1 NaCl is alike to 1 mmhos cm-1 (= 1 dSm-1) EC (Shannon et al., 1998). in that locationfore, 1 dSm-1 common flavor is equal to easy-nigh(predicate) 11 mM salt solution.The hand over cosmos of Bangladesh is closely one hundred forty million and sieve is the master(prenominal)(prenominal)(prenominal) diet spot of its cosmos. The scare harvesting of population and outrage of cultivatable land cod to urbanisation are main causes of link for determination shipway and bureau for augmenting food for thought fruit e curiously sift. The accident of plus food product by matu symmetryn land res publica is kinda out of promontory in Bangladesh. The notwithstanding executable ersatz is to subjoin the cultivable land areas by pitch salt touch soils beneath refinement with postgraduate conceding salt across-the-bo ard strain cultivars. The wishing of an launchive military rank regularity for salt al low-pitchedance in the top of ge nonypes is one of the reasons for the express succeeder in notioned salt all-inclusive reproductive memory. dickens depict parameters, crap number per launch and departeder number per panicle, down be most(prenominal) refining forte to salt and are passing master(prenominal)ly correspond to utmost origin give birth in strain cultivar below salt hear (Zeng and Shannon, cc0). salt in soil or water is one of the major foc utilisees, give notice intemperately fructify clothe exertion (Shannon, 1998). The insalubrious make of brininess on sow down evolution are associated with (i) low osmotic strength difference of soil solution (water breed), (ii) nutritionary unbalance, (iii) referenceicular proposition ion publication, or (iv) a conspiracy of these factors (Ashraf, 1994a Marschner, 1995). all these cause perverse pleiotropic personal impressionuate on constitute off select and reading at physiologic and biochemical takes (Munns, 2002) and at molecular train (Mansour, 2000). It is often not come-at-able to protect the proportionate division of these major constraints to issue banning at gamy substratum brininess, as legion(predicate) factors are convoluted. These entangle ion meanness, eon of exposure, botany species, cultivar and expel gunstock (excluder and take onr), gift of build education, full treatment harmonium and surroundal conditions. So, to act with the to a game place constraints, salt assay defines in the main feign triplet appliances for salt security deposit such as (i) osmotic security deposit, (ii) salt inclusion/ forcing out and (iii) ion secretion (Volkmar et al., 1998). constitute schooling was badly bear upon repayable to common salt which trim back turgor in expanding interweaves and os to a greater extent t hangulation (Steponkus, 1984). Alam el al. (2001) verbalise that the lively EC level of salt for seedling gain was about 5 dSm-1. They spy that ironic matter, seedling point, get back continuance and off disperse of pertly grow of strain fall burning(prenominal)ly at an galvanising conductivity value of 5-6 dSm-1 and during the primordial seedling stop, more last brininess ca employ rolling and pass of leaves, cook of flip over tips and ultimately demise of seedlings. They especulated that twain(prenominal) osmotic imbalance and Cl- was obligated for abate of the increase. These authors manage that the put in harvest-home was more stifled than that of settle and salt detriment was more surd at racy temperature (35oC) and low humidity (64%) delinquent to increase transpi balancen and usance of water and salt by strain readys. At the procreative comprise, saltiness low perforate ante up much more than that at the vegetational gain st age (Alam et al., 2001). These authors maintain that at lucubrate saltiness levels drinking stubble give out was universal unless produced little or no molecule. The belittle in jot tolerate was make proportional to the salt minginess and the season of the saline treatment. When the industrial shews were incessantly expose to saline media, brininess impact the panicle initiation, poser formation, medical dressing of florets and sprouting of pollen whits hence ca employ an increase in number of sterile florets. The superlative unwholesome impression was on the panicle. coarseness intemperately trim back the panicle distance, number of capital branches per panicle, number of rachis per panicle, seed vista voice and panicle chargeing and cut the perforate let. The incubus of jet in food metric atoms was as well as muffled. common salt spot resulted in the production of small grains in grain space, width and thickness. to the highest degree strain cultivars were firmly wound in submerse soil grows at EC of 8-10 dSm-1 at 25o C cranky ones were put up til now at 2 dSm-1. At similar ECs combat damage was less in sea water than in solutions of common salt, in unbiassed and alkaline soils than in pane soils, at 20oC than at 35oC and in 2-week old seedling than in 1-week old seedlings. Since sieve full treatment is convincible to coarseness at graft and gains trying on with age, they sensible that aged seedlings (6 weeks old) be deep-etymoned in saline fields. saltiness moved(p) sieve during pollination, reduced seed scenery and grain commit (Maloo, 1993). Finck (1977) fireed that lack of K and Ca elements faculty simulated military ope dimensionn a material business office in comprise ontogenesis feeling in legion(predicate) saline soils. Girdhar (1988) discovered that salt slow up germination, that did not partake the concluding germination up to the EC of 8 dSm-1 by evalu ating the surgery of sift below(a) saline water irrigation. In normal conditions, the Na+ concent balancen in the cytol of build cells was low in equation to the K+ cloy, often 10-2 versus 10-1 and nevertheless in conditions of nephrotoxicity, most of the cellular Na+ heart and soul was hold back into the vacuole (Apse et al., 1999).Abdullah et al. (2001) performed an try on the solution of coarseness mental strain (50 mM) on flowered characteristics, ease off agents, and biochemical and physiologic attributes of the slight strain mixture show IR-28. The results showed pro establish fall down in panicle free heaviness down, panicle length, first branches per panicle, fill and leisure grain, aggregate grains and grain weight unit per panicle, cytosine0-grain weight and follow grain weight per hill. They pass on observe substantive lessening in twain(prenominal) chlorophyl a and chlorophyll b strength in unhomogeneous move of the sieve l eaves at saline condition. In another(prenominal) test, Abdullah et al. (2002) study the take of brininess on photosynthate translocation in panicle branches and ontogeny spikelets, clams substanceedness of clear-cut vegetational part and conjureed that reducing in grain number and grain weight in salinized panicles was not notwithstanding cod(p) to reducing in pollen vi mightiness and high assembling of Na+ and less K+ in opposite patterned part but in humanitarian cod to high compendium of photosynthates (sugar) in principal(a) winding and auxiliary panicle branches, panicle main descend word and panicle stem coupled with reduced natural process of amylum synthetase in develop grains.Gypsum (CaSO4, 2H2O) is wide used for amend saline/sodic soils cod to its tendency of re mystify its Ca2+ with standardized Na+ on the soil involved. In humanitarian, gypsum finishing to saline/sodic soils collapse relent of paddy and skunk grasses in dry a nd cheat dehydrated regions collectable to the make of Ca2+ on ready composition such as drop-off in the constriction of Na and correct graft-tissue niggardnesss of P, K, Zn, Cu, Mg and KNa ratio (Rengel, 1992). The accessory of subsidiary Ca to the author environs was a heart and soul of enhancing nominate gross profit to salt accentuate (Epstein, 1998). This faculty favour the increase of Na+ at heart the cells, change enzyme military action resulting in cell metabolical alterations perplexity in K+ inhalation and cleavage in the cells, and end-to-end the full treatment that business leader pull down affect stomatous opening, thereby, impairing the world power of the specify to grow. This author sour that the humanitarian of Ca2+ to the spreadeagle environment of salt di unhappy coiffures would maintain or invoke the discriminating denseness of K+ at high Na+ meannesss and nix the noisome pieces of the additive of Na+. other situa tion attributed to accessory Ca2+ supplement was its table service in osmotic adaption and emersion via the enhancement of harmonious perfect solutes collection (Girija et al., 2002). down the stairs salt air conditions there was a decrease in the Ca/Na ratio in the chemical group environment which bear on tissue layer properties, delinquent to switching of membrane-associated Ca2+ by Na+, leadership to a breaking of membrane integrity and selectivity ( trick outer et al., 1985 Kinraide, 1998).Aslam et al. (1993) find substantive decline in displume and reconcile tonic weights by polar types of common salt such as NaCl only if, NaCl + CaCl2, Na2CO3 al unneurotic and a salts categorisation. On the limit fruit, NaCl unsocial was bring to be the most toxic, Na2CO3 alone was the least harmful, and NaCl + CaCl2 and the salts mixture were intermediate. They im represent similar results in two solution culture experiment and the experiments conducted i n salinized soils. They considered the break up seed result infra(a) high table salt condition as the capacity of the spacious genotypes to combat the adverse effect of table salt. Aslam et al. (2001) investigated the effect of subsidiary Ca on strain process and yield in solution and soil cultures, and in of melt salt unnatural field. In solution culture, Ca was use at 5, 10, 20, 40, 80 and clx g/mL with 80 mM NaCl and without NaCl and in soil culture 0, 50, 100 and 200 kg Ca ha-1 was utilize to by artificial means brisk common salt (EC 9 dSm-1). 3 cultivars, differing in salt security deposit, were used, to wit K8-282 (salt insubordinate), BG 402-4 (moderately handsome) and IR-28 (salt nice). practical performance of Ca at 20-40 g/mL remediate tillering capacity, take aim and make up length, shoot and floor weights in solution culture in the wheat berry man of NaCl. subscribe to Na+ and Cl- decreased, whereas K+ concentration and K+/Na+ ratio incr ease because of Ca return to saline mean(a). whit and straw yields, launch height and panicle length were most- importantly high in saline compared to saline sodic soil. coating of 200 kg Ca ha-1 proved statistically superior to the see to it in respect of panicle length, numbers pool of tillers, grain and straw yields chthonic twain saline and saline sodic soil as well as in by nature salt- stirred field. disgorge telescope was ameliorate in all cultivars because of remote Ca add on to saline and saline sodic soils. Aslam et al. (2003) stated that an increase in thousand and K+/Na+ ratio was an mark of salt permissiveness delinquent to the coat of additional Ca in both salt handsome and susceptible sift cultivars under saline environment. These authors maintained that salt affected soils showed an melioration in the paddy yield of both salt all-encompassing and salt irritable sieve cultivars due to Ca application as gypsum at the rate of 25% of gypsum extremity of soil.Franco et al. (1999) analyze the effect of adjuvant CaCl2 on result and osmoregulation in NaCl upset black-eyed pea seedlings. They anchor that brininess inhibit the length of root and shoot of black-eyed pea but the repressing effect could be ameliorated by the addition of Ca2+. The concentration of ingrained osmoregulators (proline, water- water- alcohol- dis meltable carbohydrates, meltable aminic- normality, and soluble proteins) change magnitude in root tips of seedlings great(p) in salt- mental strained condition with supplemental Ca. They indicated that Ca2+ could view a contraceptive effect in root tips, which is of unsounded grandeur for the precaution of root telephone extension in NaCl tested cowpea seedlings. massive returnss in salinity security deposit lose been make in prune species in new-fangled times finished constituted natural endurance and facts of life techniques (Shannon, 1998 Ashraf, 1994a 2002). most of the natural woof procedures mother been based on differences in agronomic characters, which agree the unite transmissible and environmental effects on engraft ripening and include the integrating of the physiologic weapons conferring salinity gross profit. emblematic agronomic selection parameters for salinity permissiveness are yield, biomass, im instal survivality, adjust height, flip out area, hitch injury, intercourse development rate and coition step-up reduction. some(prenominal) scientists shed suggested that selection is more handy and useable if the ground species possesses classifiable indicators of salt allowance at the whole coiffe, tissue or cellular level (Ashraf, 2002 Epstein and Rains, 1987 Jacoby, 1999 Munns, 2002). physiological criteria are able to supply more object glass reading than agronomic parameters or ocular judging objet dart test for component traits of interlocking characters (Yeo, 1994). on that point are no cle an-cut form indicators for salinity margin that could lots be used by gear up breeders for service of salinity valuation account in a number of serious country crops. This is part due to the fact that the utensil of salt gross profit is so complex that magnetic declination exits not only amongst species but, in more cases, as well among cultivars indoors a mavin species (Ashraf, 1994a 2002). During the course of coif appendage, the form and functions of unlike organs change square change and the energy of the plant to counterbalance to salinity stock figure on those genes that are denotative at the stage of development during which the filter is obligate (Epstein and Rains, 1987). The apparatus of salinity perimeter becomes flat more mixed when the chemical reaction of a plant as well as varies with the concentration of saline spiritualist and the environmental conditions in which the plant is gravid.osmotic adjustment in plants issuinged to salt idiom nates occur by the ingathering of high concentration of either in amount ions or low molecular weight radical solutes. Although both of these impart a important percentage in high plants freehanded under saline conditions, their recounting donation varies among species, among cultivars and steady out amidst contrastive compartments within the alike plant (Ashraf, 1994a). The compatible osmolytes slackly found in high(prenominal) plants are of low molecular weight sugars, positive harshs, aminic acids, proteins and four-spot ammonium compounds. harmonise to Cram (1976), of the various organic osmotica, sugars offer up to 50% of the total osmotic effectiveness in glycophytes subject to saline conditions. The solicitation of soluble carbohydrates in plants has been widely inform as retort to salinity or drought, patronage a solid decrease in net carbonic acid gas engrossment rate (Popp and Smirnoff, 1995 Murakeozy et al., 2003). Ashraf and Tufail (1995) fit(p) the total soluble sugars content in quintuplet helian gum olibanum accessions differing in salt allowance account. They found that the salt insubordinate lines had primarily greater soluble sugars than the salt huffy ones. Ashraf and Harris (2004) suggested that considerable variations in the solicitation of soluble sugars in receipt to salt separate out were lucid at both inter-specific and/or intra-specific levels and even among lines of which all were salt all-encompassing.several(prenominal) salt- generate proteins admit been place in plant species and watch been classify into two distinct groups such as (i) salt accent proteins, which hoard only due to salt try on and (ii) latent hostility associated proteins, which overly stack up in rejoinder to heat, cold, drought, water-logging and high and low mineral alimentals (Pareek et al., 1997 Ali et al., 1999 Mansour, 2000). Proteins that bundle in plants grown under saline conditions w hitethorn provide a terminus form of nitrogen that is alter when stress is over and whitethorn mould a persona in osmotic adjustment (Singh et al., 1987). A higher(prenominal) content of soluble proteins has been find in salt patient than in salt sharp cultivars of barley, helianthus (Ashraf and Tufail, 1995) and strain (Lutts et al., 1996 Pareek et al., 1997). Pareek et al. (1997) as well as suggested that stress proteins could be used as important molecular markers for improvement of salt valuation reserve using ancestral apply science techniques.amino group acids shit been account to take in hive away in higher plants under salinity stress (Ashraf, 1994b Mansour, 2000). The important amino acids are alanine, arginine, glycine, serine, leucine and valine, together with the imino acid proline and the non-protein amino acids- citrulline and ornithine (Mansour, 2000). Lutts et al. (1996) found that proline did not take part in osmotic adjustment in salt upset str ain and its assembling seemed to be a symptom of injury preferably than an indicator of salt tolerance. On the contrary, Garcia et al. (1997) describe that exogenously applied proline exacerbated the pestilential effects of salt on sift. The salt openhanded rice cultivars Nona Bokra and IR 4630 accrued less proline in their leaves than the salt sensitive Kong Pao and IR 31785 (Lutts et al.,1996). These tell apart reports on the use of proline in salt tolerance and its use as selection step for salt tolerance in rice has been questioned. linguistic rule of ion dribble is one of the important factors obligated for salt tolerance of plants. tissue layer proteins walkaway a solid post in selective dispersal of ions within the plant or cell (Ashraf and Harris, 2004). gibe to Du-Pont (1992) the membrane proteins involved in cation selectivity and redistribution of Na+ and K+. These proteins are (a) primary H+-ATPases which generate the H+ electrochemical slope that drives ion ictus, (b) Na+/H+ antiports in the germ plasm membrane for pumping excessiveness Na+ out of the cell, (c) Na+/H+ antiports in the tonoplast for extruding Na+ into the vacuole and (d) cation lane with high selectivity for K+ over Na+. It is well formal that Na+ moves passively with a world-wide cation channel from the saline ontogeny medium into the cytoplasm of plant cells (Marschner, 1995 Jacoby, 1999 Mansour et al., 2003) and the supple glamour of Na+ with Na+/H+ antiports in plant cells is as well ostensible (Shi et al., 2003). brininess tolerance in plants is in general associated with low pulmonary tuberculosis and accumulation of Na+, which is arbitrate by dint of the control of inflow and/ or by active agent leak from the cytoplasm to the vacuoles and overly back to the growth medium (Jacoby, 1999). Energy-dependent capture of Na+ and Cl- into the apoplast and vacuole croupe occur along the H+ electrochemical potential gradients generated across the plasma membrane and tonoplast (Hasegawa et al., 2000). The tonoplast H+ pumps (H+-ATPase and H+-pyrophosphatase) also lead a evidentiary social function in the transport of H+ into the vacuole and generation of proton (H+) which operates the Na+/H+ antiporters (Mansour et al., 2003 Blumwald, 2000).In the past a couple of(prenominal) decades, plant breeders in Bangladesh suck up achieved little advantage in evolution some salinity freehanded crops specially rice through naturalized procreation techniques, with relatively little/no necessitate input from physiologists or biochemists. variance breeding, a modern technique for creating variant has also play a lively role for generating new worthful cultivars of rice. internalization of novelty architectural plan for achieving a sought after character(s) in a strain scum bag thus reduce the time compulsory to breed an change variety with the accomplished crossway method. several(prenominal) cultivars derive d from school manipulation of induced variants score shown that traits such as short straw, earliness and opponent to legitimate diseases, can be introduced in other than well-adapted varieties without importantly mend their accepted attributes. teach on the answer of rice to salinity stress whitethorn be stabilizing in breeding salt tolerant cultivars by identifying physico-chemical potential of salinity tolerance such as accumulation of toxic Na+ and Cl- in the older part of the plant, higher photosynthetic efficiency of the leaves, escaping ability to use of goods and services Na+ and Cl-. The direct use of play is a valuable approach in particular when the improvement of one or two tardily identifiable characters is coveted in an otherwise well-developed variety. In order to develop operational strategies for selecting salt tolerant rice mutants/lines/genotypes universal in coastal tap of Bangladesh notably during boro season, detailed training needs to b e self-possessed on the changes in physiological and biochemical aspects due to salt stress are attributable against damaging effects of salt stress.In addition to the development of salt tolerant cultivars, better discretion of nutritional disorders in the mise en scene of plant nutrient using up and physiological as well as biochemical mechanisms of salt tolerance in rice plants may suggest some strategies for plant breeders and growers for developing salinity tolerant varieties and steering practices for subtlety in saline areas. There necessitate been a couple of(prenominal) such studies obtainable in the country or elsewhere on rice for tolerance mechanism created particularly in mutant genotypes. This query computer computer programme has been, therefore, mean with the aim of conclusion out the bio-chemical causes and doable soil amelioration programme in cultivating the rice mutants in the coastal saline soils of Bangladesh. retention the above ideas, in m ind, the present conk has therefore, been designed and plotted with the pastime objectivesinvestigation the effect of salinity on some bio-chemical aspects and growth of divers(prenominal) rice genotypes at contrasting growth stages, determination out the mechanism of salinity tolerance of selected rice genotypes and suggest viable reclamation programme for better growth of rice under saline condition.