Some Shortcomings of Existing Methods and Lessons for the Future

The rice case study illustrates the power of the priority setting tools described above. Fairly simple economic concepts led to a dramatic result the decision to focus resources on a relatively small range of programs with high potential payoffs. Other studies show that the same techniques can be used in a wide range of research organizations at the local, national, and international level. Still, the priority-setting techniques currently in use are limited. On some issues, they offer little...

Integrated Nutrient Management

Exhaustive cropping systems like wheat rice, wheat cotton, rice rice etc. have hastened the pace of soil health degeneration. The impact is seen in the plateauing yield levels of major crop-based rotations. At present Indian agriculture is mining nearly 10 million tons of nutrients. In spite of the new technologies continuously emerging on the scenes of action, maintaining the yield growth has become increasingly difficult and costly, mainly due to inefficient input use and declining quality of...

Analysis of the In Vivo Roles of DREB1A and DREB2A by Using Transgenic Plants

We generated transgenic plants in which DREB1A or DREB2A cDNAs were introduced to overproduce DREB proteins to analyze the effects of overproduction of DREB1A and DREB2A proteins on the expression of the target rd29A gene. Arabidopsis plants were transformed with vectors carrying fusions of the enhanced CaMV 35S promoter and the DREB1A (35S DREB1A) or DREB2A (35S DREB2A) cDNAs in the sense orientation.14,19 All of the transgenic plants carrying the 35S DREB1A transgene (the 35S DREB1A plants)...

Interaction Among Water Nutrients and Roots

There is no doubt that water is a scarce resource in the SAT, but this does not mean that water always limits growth and production of crops. It should be more accurate to say that the natural supply of water does not match the crop demand in time and space. Water cannot be properly supplied to crops when and where they require it, because of erratic rainfall pattern, loss from soil surface through pan evaporation and loss into deep soil layers through leaching. Water is a resource beyond...

Alkali Soil Formation Characterization and Its Distribution in China

Saline Alkali Soil China

Alkali soil is formed when soil colloidal materials are inundated for a long period with groundwater whose chemical composition is predominantly sodium carbonate or sodium bicarbonate. Fig. 10.1 shows the concept of alkali soil formation. These sodium salts in the groundwater are produced when carbon dioxide in soil or atmosphere is absorbed by sodium hydroxide, which is hydrolyzed from sodium ions. With ionic absorption on the surface of soil colloids, predominantly by sodium ions, soil...

Physiology and Biochemistry of Nitrogen Recycling in Rice Plants

Under sufficient light conditions, the assimilation of inorganic nitrogen and efficient recycling of the assimilates within plants are the most important processes for determining the productivity and quality of many crops. The major source of nitrogen for developing leaves and spikelets in rice plants is the nitrogen remobilized, via the phloem, from older, senescing organs.1 In particular, senescing leaf blades are the major source of nitrogen and they contribute about half of the nitrogen in...

Reclamation of Salt Affected Soils

Reclamation of salt-affected soils by leaching is commonly used, and considered to be one of the most feasible and economical choices. Leaching efficiency is a function of 2. Water application modes (intermittent ponding or sprinkling or continuous ponding) 3. Types and amount of salt present, etc. Leaching efficiency has been comparatively studied in both field and laboratory conditions. In the field study, the traditional leaching method was considered ponding water continuously on the soil...

Osmotic Adjustment

Most organisms increase the cellular concentration of osmotically active compounds, termed compatible solutes (Table 19.1), when in danger of becoming desiccated by either drought conditions or external lowering of the osmotic potential.17-20 The accumulating compounds are compatible with normal cellular metabolism at high concentrations.21 Often these are hydrophilic, which gave rise to the view that they could replace water at the surface of proteins, protein complexes, or membranes. The...

References

Boulder Office of Interdisciplinary Earth Studies, 1991 81. 2. Grainger A. Characterization and assessment of desertification processes. In Chapman GP, editor. Desertified Grasslands Their Biology and Management. Linnean Society Symposium Series, No. 13. London Academic Press 1992 17-33. 3. Thomas DSG. Science and the desertification debate. J Arid Environ 1997 37 599-608. 4. Lopez-Oca a C. Effectiveness of international regimes dealing with desertification...

Varietal Improvement

Following the introduction of the Norin dwarfing gene-based high yielding varieties of spring wheat Sonora 64 and Lerma Rojo in the early sixties and the Dee-Geo-Wu-Gen dwarfing gene-based high yielding rice varieties Taichung (Native) 1 and IR8 in the mid-sixties, a major breakthrough in yield was achieved. Whereas high level of response to applied fertilizer combined with non-lodging habit ensured high yields, photo-insensitivity conferred wide adaptability and early maturity helped increase...

Physical

A very large proportion of the area under various food crops fall under a low productivity category. The share of low productivity area varies from 57 in coarse cereals to 92 in oilseeds. Their yield levels are about 40 less than in high productivity areas. For instance, in rice and wheat the yield level in low productivity areas are respectively 2538 and 2032 kg ha as against 2867 and 3828 kg ha in high productivity areas. In these areas technology transfer and measures for enhancing input use...

The Global Water Situation

Water is a renewable resource which is intercepted (or appropriated) by man as it moves through the hydrologic cycle. This cycle, which is ultimately driven by solar energy, carries water from the atmosphere to the land and oceans and back again. The largest flux appropriated for human use is the portion of natural evapotranspiration emanating from harvested forests and dryland agriculture. The global long-term average is about 18.2 x 103 km3 yr. This is about three times the annual flow of the...

Why is RuBisCO the Target

Balancing the rate of the conversion of photon energy into chemical energies such as NADPH and ATP, and those of the inflow of CO2 from the atmosphere and of the reduction of the fixed CO2, is the critical point for land plants. If the rate of the energy utilization is lowered by the decreased inflow of CO2 through the stomata, chloroplants are obliged to direct energies to photorespiration and reduction of oxygen molecules to superoxide radicals (O2-).' O2- is dismutated to hydrogen peroxide...

Forced Ventilation Micropropagation Systems and Their Application

Forced ventilation is a method of ventilation which involves the use of mechanical force such as an air pump and an air compressor to flush in a particular gas mixture directly through the culture vessel. With this system, the gaseous composition (CO2, water vapor, etc.) of incoming air and forced ventilation rate and or air current speed in the culture vessel can be controlled relatively precisely by use of a needle valve, mass flow controller or an air pump with an inverter.4-6 One of the key...

Supply Driven Resource Allocation

Ruttan (pp. 269-70)1 notes that in spite of the problems with congruence methods of priority setting, the basic notion of congruence offers a useful reference point for resource allocation. He suggests that research administrators should be prepared to justify large deviations from congruence. Ruttan notes that research administrators often prefer to focus entirely on supply-driven research agendas, in which nearly all programs are motivated by perceived scientific opportunities. He wryly...

Permeability of Salt Affected Soils

The rate of infiltration, which refers to the rate of water entry into the soil, generally increases with increasing salinity and decreases with either decreasing salinity or increasing sodium content relative to calcium and magnesium (SAR). A column study on the effect of water quality on saturation hydraulic conductivity was conducted in the laboratory. Silty clay that contained 40 clay from the B horizon of the experimental plot was tested. Soil samples were packed into plastic cylinders...

MCS Sse I

(iiiiioii) t rbcS-V 1 ipt 1 Fig. 25.4. Construction of new MAT vectors. The ipt genes are jointed to a native or rbcS promoter. The R (recombinase) genes fused with a 35S promoter have an intron sequence of Eucalyptus histone genes. The gusA and nptll genes are second selectable marker genes. Unique Smal and BamHI sites (A) binary type or MCS, multicloning sites (B), two component type of lacZ' DP Dumb quoteare available for cloning of desirable genes. In current transformation methods, we...

Introduction

Drought Response Gene

Drought, salt loading, and freezing are environmental conditions that cause adverse effects on the growth of plants and the productivity of crops. Plants respond to these stresses at molecular and cellular levels as well as physiological levels. Expression of a variety of genes has been demonstrated to be induced by these stresses.1,2 The pro ducts of these genes are thought to function not only in stress tolerance but also in the regulation of gene expression and signal transduction in stress...

Functions of Compatible Solutes

Compatible solutes are non-toxic to protein structure and function, and alleviate inhibitory effects of high ion concentrations on enzyme activity. Some, such as trehalose, do not respond to osmotic stress by accumulating but are protective even at low concentra-tions.43-44 The majority of the compatible solutes, however, also seem to have osmoregu-latory functions and accumulate in response to osmotic stress. They may function as osmolytes as well as osmoprotectants. The net increase of...

In Vitro Acclimatization and Rooting20

The term acclimatization is defined in this chapter as the environmental adaptation of a tissue-cultured or micropropagated plant that has been moved to a new environment, i.e., a greenhouse or a field environment. During the acclimatization, the plant's environment is changed gradually with time, Table 28.3. Experimental description of Coffea arabusta Ventilation rate (ml h-1 platelet) * S and F at the left represent sugar-containing and sugar-free medium A and F at the middle represent agar...

Improvement of MAT Vectors

In our evaluations of two prototype MAT vectors, we found several problems with practical use and developed new MAT vectors (pMAT21, 22, 101, pTL7, pIPT53, 54, prol103, Table 25.1. Transformation efficiency of tobacco plants ESP lines which formed normal shoots after infection after infection Vector Number Number ( ) Number ( ) pNPI pNPI Transformation of tobacco plants using pNPI 106 and 132 vectors, and appearance of marker-free transgenic plants at hormone-free MS medium. 108) (Figure 25.4)....

Groundwater Overdrafts

Consistently falling groundwater levels are an indicator of overexploitation. They are observed worldwide. In northern China,4 western India5 and South Africa,6 groundwa-ter tables are declining at rates between 1 and 3 m per year. The abstractions in the Sahara and Saudi Arabia deplete aquifers which since the last ice age have not had any recharge to speak of.7 It is estimated that by 2010 the deeper aquifers of Saudi Arabia will have only 40 of their 1985 water reserves left.2 The present...

Altering Carbohydrate Composition Starch

Completely different is the picture for approaches to modifying carbohydrate composition in an attempt to improve plant quality. There are many reports on successful modification of starch composition in potato, pea or other species, and also on the production of fructans in transgenic plants that are normally not capable of fructan production. Starch is a glucan polymer that is synthesized from activated glucose units that are synthesized from G6P and ATP by ADP-glucosepyrophosphorylase. The...

Structural Analysis

RuBisCO is composed of 8 large subunits and 8 small subunits. The peptide of the large subunit has two domains the N-terminal domain from residues 1 to 150 and the C-terminal domain from residues 151 to 475 in spinach RuBisCO. In the C-terminal domain, the C-terminal end of a p-sheet is connect to an a-helix with a loop. In total, 8 p-sheet-loop-a-helix structures are linked by 7 loops. Eight p-sheets construct a barrel structure which is covered by 8 a-helices. The amino acid residues involved...

Rely on Scientific and Technological Progress to Achieve the Balance Between Grain Supply and Demand

To promote agricultural development through scientific and technological progeress has become the basic feature of modern agriculture. In the past several decades, the proportional contribution made by scientific and technological progress in agricultural growth has been getting higher (Table 2.8). Research on crop germplasm in China has held the leading position in the world. Breeding research on main cereal crops has produced a higher level in the yield, quality and disease resistance of the...

In Situ Conservation

Few major crops were domesticated in Japan. Most of Japan's cultigens were introduced initially from China and Korea, and subsequently from other regions. One major crop which could have been domesticated in Japan is the azuki bean, Vigna angularis var. angularis. The fact that today Vigna angularis consists of a wild weed crop complex17 is one reason to think that this crop could have been domesticated in Japan. Recent research at the NIAR has focused on the population structure to be found in...

Export of Glutamine from Senescing Leaves

Our immunological and immunocyto-logical studies have suggested that GS1 is important for the export of nitrogen from senescing rice leaves.11-13 During natural senescence of a leaf blade of rice plants, the contents of GS2 declined in parallel with other chroloplastic enzymes such as RuBisCO and Fd-GOGAT. In contrast, the GS1 protein remained relatively constant throughout the senescence period.12 When various positions of leaves are tested, the relative content of GS1 protein was found to be...

Info

Hormone synthetic genes ipt used for selection are removed after transformation. (A) Recombination between two directly repeated sites (RS) results in deletion of the ipt gene lying between the sites. (B) Marker-free transgenic plants are identified as normal shoots which recover apical dominance. (a) Regeneration of adventitious shoots (b) Differentiation of abnormal shoots which have lost apical dominance (c) Appearance of normal shoots which have recovered...

Technical

India's biological diversity continues to be rich, one of the 12 megacenters of plant diversity. This diversity needs to be preserved, and the immediate task will be to devise and enforce time bound plans for saving endangered plant and animal species as well as habitats of biological resources. This is considered most important, as with the advent of new tools and techniques there is no barrier to gene flow, and the living systems could be termed one gene pool with tremendous options and...

Radical Oxygen Species are Unavoidable and Increase During Stress Episodes

Compatible solutes may also function as oxygen radical scavengers. Evidence for such a function comes from studies on fungal pathogen interactions where the pathogens are protected by the synthesis and secretion of mannitol. Plants and animals produce oxygen radicals in response to pathogen attack. The rapid production and local accumulation of reactive oxygen species leads to localized cell death in the host, which then may limit the spread of the pathogen.56 In response, some pathogens seem...

Important Roles of the DRE Binding Proteins During Drought and Cold Stresses

Yeast One Hybrid

Two cDNA clones that encode DRE binding proteins, DREB1A and DREB2A, were isolated by using the yeast one hybrid screening technique.14 The deduced amino acid sequences Fig. 20.2. Signal transduction pathways between initial dehydration stress signal and gene expression. There are at least four signal transduction pathways two are ABA dependent (I and II) and two are ABA independent (III and IV). Protein synthesis is necessary for one of the ABA-dependent signal pathways (I). ABRE is involved...

Factors Determining Food Shortage in the Early 21st Century

The world grain stock use ratios (ratio of stock volume against use volume), which are the criteria for global availability of grain, have shown a tendency to fall since 1987 (Fig. 1.1). According to USDA data, except for 1997 98 the world average stock use ratio for all grain has been below 17 since 1994 95 this is considered by the FAO to be a dangerously low stock level. The ratio is at around the lowest level since the war, and is about the same as the level during the food crisis year of...

Watcher Security Co Sl

State of the World's Plant Genetic Resources. Rome FAO, 1996. 2. GREAN. Global Research on the Environmental and Agricultural Nexus The report of the Taskforce on Research Innovations for the Productivity and Sustainability, Gainsville and Ithaca University of Florida and Cornell University, 1997 160. 3. Raman KV. Public and private research Promoting synergies. In Chopra L, Singh RB,Vera A, eds. Crop Productivity and Sustainability, Shaping the Future. Proceeding of the 2nd International...

Sea Water Intrusion

In coastal areas over-exploitation of groundwater leads to seawater intrusion (see, e.g., SWIM'96).13 Due to the density difference between fresh and saline water, a saltwater wedge forms naturally in coastal aquifers. If the freshwater flow is diminished by pumping, the wedge will proceed further inland, eventually leading to the contamination of wells. Wells which are screened in the freshwater layer may still draw salt by the phenomenon called upconing.14,15 At present, six out of ten people...

Salinization

Salinization and related drainage problems are commonly associated with irrigated agriculture, especially in arid and semi-arid regions. In the dryland agriculture practiced in humid regions, most of the water in the crop root zone originates from rainfall, which has low salinity. The small amount of salt that enters the system is flushed through the root zone by the relatively large amount of excess water (water exceeding crop evapotranspiration and natural evaporation) available. By contrast,...