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1) Exploiting the potential of halophytes as source of edible oil |
Pakistan is currently facing the severe shortage of good quality water for human consumption and for conventional agriculture. Irrigated land is more susceptible to salinity and it is estimated that large cultivated areas in Pakistan are becoming saline. Halophytes can be used as oil-seed crop on highly saline soils or where available water is of poor quality. There are reports which indicate that some of the halophytes have better quality edible oil in comparison to most commonly used Palm oil in Pakistan. The seed oil study of different halophytes showed that the average un-saturation for the fatty acids in the seed oil was 84 percent, which is favorable from nutritional point of view. These studies showed that the oil from the halophyte seeds is of high quality. However, in selecting such a crop several different considerations should be taken into account; i) suitability of the crop in a given ecosystem, ii) quality of the oil, iii) potential of being used as edible oil, iv) ease of harvesting, v) oil content, vi) protein meal quality, vii) quantity of ash present, viii) sustainable irrigation system, ix) management of cultivated lands, etc. The use of halophytes from Pakistan as a seed oil crop seems to be the available alternative.
We are proposing here the use of perennial halophytes that could be grown once and could be managed for a very long time without reseeding. This would significantly save time and efforts to grow them and would make them economically viable. Fine-tuning of the technology would be required to address the local environmental constraints. |
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2) Use of Halophytic shrubs as alternate source of cattle fodder |
Pakistan faces an acute shortage of meat and dairy products. The demand is on the increase and the production gains are insufficient to meet the shortage. In cattle breeding, improper nutrition produces weak animals which are prone to diseases. Selection of a suitable breed for particular purpose i.e. milk or meat production and proper management of the flock are necessary for optimum production.
Diet and health care are important factors for raising a good flock. The animals are generally fed a mixture of dry and green fodder, which are in short supply and expensive to procure. Wheat / rice straw are generally the most common dry fodder while corn / sorghum are major green fodder. All these crops require good land and good water for their growth. Sweet arable lands and good quality irrigation water, which are becoming scarce with time, are needed for producing crops for human consumption. The pastures and grazing lands hence, have to rely on rain (unreliable source) and may occupy less productive areas like salt effected lands where vegetation changes to more hardy plants species i.e. halophytes.
While the halophytes may be productive under harsh conditions of high salt contents of soil, which they manage by balancing their internal osmotic potential through salt accumulation in foliage, their consumption by animal requires proper feeding trials for monitoring the ill effects, if any, on the animal health. The present project aims at studying the possibility of decreasing dependence on traditional dry and green fodder by replacing them with suitable halophytic plants.
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3) Screening and eco-physiological studies of halophytic grasses for utilization as forage |
Soil salinity and/or sodicity have caused havoc all over the world rendering vast tracts of agricultural lands unfit for conventional crops. These salt affected areas could, however, be utilized for raising cash-crop halophytes which are well equipped to survive and complete their life cycle in saline soils. Properly managed irrigation systems using saline-sodic soils and brackish water have the potential to sustain and improve crop production with minimum adverse environmental consequences. The proposal aims at finding suitable local halophytes and developing methods for optimizing their growth to be utilized as cattle fodder to produce meat for local consumption as well as for export, if feasible. This would also help in rehabilitation of saline and sodic lands, improve productivity per unit of water, besides developing a sustainable fodder crop using saline water irrigation on lands which at present are lying barren. |
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4) Salt-induced oxidative stress, consequences and possible management |
Salinity is the most important of the agricultural problems of the semiarid and arid regions including Pakistan. Furthermore, salt deserts (caused by drought or a lack of fresh water) and saline inland basins (caused by the level of saline ground water rising as a result of leakage of drainage water) are being created. These degraded areas could be economically productive if we could understand the physiology of salt tolerance of both conventional and non-conventional crops. Abiotic stresses cause the oxidative stress or enhanced production of reactive oxygen species (ROS) like OH-, O-2 and H2O2. These ROS can damage essential membrane lipids as well as proteins and nucleic acids of cells. Levels of ROS in plant cells are normally controlled by protective antioxidant activity. However, under environmental stresses, like temperature or drought ROS production can increase and protective antioxidant activity may then becomes inadequate, which may lead to plant or seed fatality. Although, a considerable attention has been paid to this aspect for few decades but all such investigations are confined to other than saline stress. Little work has been reported on the oxidant and antioxidant activities under saline conditions. We will investigate the role of oxidants, antioxidants and their enzymes at various stages of the plants life cycle growing under saline conditions. |
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5) Small-scale resource heterogeneity among halophytes in some coastal communities of Pakistan |
Salt marshes and salt deserts are considered as wasteland, however, such habitats are national assets and harbor many salt tolerant species with a high economic potential for increased food and fiber production and of medicinal importance. Besides, they are a crucial part of the complex natural ecosystems which they help to sustain. Currently, all over the world over, the ultimate goal is the sustainable development of non-conventional crops and practices to fit the environment. Natural habitats are being preserved and disturbed communities are restored in order to preserve the biodiversity. All this can best be accomplished by understanding the distribution and eco-physiology of species already adapted to diverse saline environment. About 100 species of halophytes are reported along the coastal areas of Pakistan but little empirical data is available about the current status of vegetation distribution patterns, soil nutritional status and the underlying mechanisms influencing vegetation ecology. In order to achieve these objectives, the following points will be investigated: 1. Distribution pattern of coastal halophytic communities along environmental gradients, 2. The relative importance of various soil nutrients in the growth and distribution of coastal communities 3. Categorization of community types with respect to micro-habitat variation and 4. The eco-physiological responses (osmo-regulation, osmotic adjustment, photosynthesis) of selected halophyte communities in different environmental conditions. |
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6) Stress tolerance in mangroves |
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Mangroves, distributed along the coasts of Pakistan, are ecologically and economically important. They provide breeding ground for crustaceans and fishes, serve as a sanctuary for migrating birds and protect the ports of Karachi and Bin Qasim against siltation. Pollution, lopping by inhabitants and diversion of river water from irrigation system are causing mass extinction of some mangrove species. Although, some of the species have been re-introduced both in the deltaic and coastal regions recently but, there is a need to understand mechanisms of their response to salt induced oxidative stress. The degraded mangrove wetlands could be rehabilitated and become economically productive if we could understand their physiology of salt and oxidative stress. Preliminary investigations have shown that Avicennia marina is the most salt tolerant species and Rhizophora mucronata & Ceriops tagal could tolerate moderate to high salinities however, scavenging of Reactive Oxygen Species (ROS) through enzymatic and non-enzymatic pathways including the role of osmotica are the research areas that need to be addressed in detail. Although considerable attention has been paid to such studies on other halophytes and a few mangrove associates, no work has been reported on our local species. It is hence proposed to investigate the role of antioxidant enzymes, osmotica and effect of different chemicals on growth of mangrove species under salt induced oxidative stress which would enable us to understand their response and subsequently lead to rehabilitation of the degraded ecosystems. |
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