Yield and Osmotic Adjustment Capacity of Barley Under Terminal Water-Stress Conditions

This paper reports the influence of the osmotic adjustment capacity and turgor potential (TP) on tolerance to drought in 12 cultivated genotypes, six breeding lines and six cultivars of barley (Hordeum vulgare L.) under terminal water-stress conditions. When the crops reached the flag leaf stage, half of the experimental plots in which they were grown were submitted to water stress treatment and the remainder maintained under optimal irrigation conditions. Differences were seen in the osmotic adjustment, relative water content (RWC) and water potential (WP) of the different genotypes. Two of the breeding lines showed the greatest osmotic adjustment capacities, maintaining their TPs better than the other genotypes studied. A positive, significant correlation was found between yield and osmotic adjustment capacity, RWC and WP under water-stress conditions. Osmotic adjustment capacity and TP were linearly related, indicating that as water stress increases osmotic adjustment favours the maintenance of higher TPs. Significant correlations were found between osmotic adjustment capacity and grain filling rate and grain yield. Under conditions of terminal water stress, yield was negatively correlated with the number of days to ear emergence; no correlation was found between osmotic adjustment capacity and earliness. Early ear emergence, a good osmotic adjustment capacity and high RWC values all contributed to yield increases under terminal water-stress conditions.

[1]  H. Nayyar,et al.  Genotypic Variation in Wheat in Response to Water Stress and Abscisic Acid-Induced Accumulation of Osmolytes in Developing Grains , 2004 .

[2]  Moinuddin,et al.  Osmotic Adjustment in Chickpea in Relation to Seed Yield and Yield Parameters , 2004, Crop Science.

[3]  J. Tenorio,et al.  Correlation between yield and osmotic adjustment of peas (Pisum sativum L.) under drought stress , 1992 .

[4]  M. Tan,et al.  Chromosomal Location of a Wheat Osmoregulation Gene Using RFLP Analysis , 1996 .

[5]  B. Carver,et al.  Water relations in winter wheat as drought resistance indicators , 1988 .

[6]  Neil C. Turner,et al.  Crop Water Deficits: A Decade of Progress , 1986 .

[7]  A. Blum.  Osmotic adjustment and growth of barley genotypes under drought stress , 1989 .

[8]  F. Hamidou,et al.  Physiological and Biochemical Responses of Cowpea Genotypes to Water Stress Under Glasshouse and Field Conditions , 2007 .

[9]  E. J. Knights,et al.  Adaptation to water-deficit in chickpea breeding lines by osmoregulation: relationship to grain-yields in the field , 1991 .

[10]  P. Bruckner,et al.  Rate and duration of grain fill in spring wheat , 1987 .

[11]  A. Hall,et al.  Osmotic adjustment and yield maintenance under drought in sunflower , 2002 .

[12]  Mark E. Cooper,et al.  LEAF WATER POTENTIAL AND OSMOTIC ADJUSTMENT AS PHYSIOLOGICAL TRAITS TO IMPROVE DROUGHT TOLERANCE IN RICE , 2002 .

[13]  J. Morgan,et al.  Water Use, Grain Yield, and Osmoregulation in Wheat , 1986 .

[14]  D. This,et al.  QTL for relative water content in field-grown barley and their stability across Mediterranean environments , 2003, Theoretical and Applied Genetics.

[15]  J. M. Lilley,et al.  Expression of osmotic adjustment and dehydration tolerance in diverse rice lines , 1996 .

[16]  S. Fukai,et al.  Development of drought-resistant cultivars using physiomorphological traits in rice , 1995 .

[17]  R. Munns.  WHY MEASURE OSMOTIC ADJUSTMENT , 1988 .

[18]  J. Morgan.  Osmoregulation as a selection criterion for drought tolerance in wheat , 1983 .

[19]  J. Tenorio,et al.  Turgor maintenance, osmotic adjustment and soluble sugar and proline accumulation in 49 pea cultivars in response to water stress , 1998 .

[20]  J. Morgan.  Growth and yield of wheat lines with differing osmoregulative capacity at high soil water deficit in seasons of varying evaporative demand , 1995 .

[21]  J. Morgan.  Pollen grain expression of a gene controlling differences in osmoregulation in wheat leaves : a simple breeding method , 1999 .

[22]  I. Martı́n,et al.  BARLEY YIELD IN WATER-STRESS CONDITIONS. THE INFLUENCE OF PRECOCITY, OSMOTIC ADJUSTMENT AND STOMATAL CONDUCTANCE , 1999 .

[23]  H. Nguyen,et al.  Consistent differences among wheat cultivars in osmotic adjustment and their relationship to plant production , 1999 .

[24]  J. Morgan.  A gene controlling differences in osmoregulation in wheat , 1991 .

[25]  R. Lafitte.  Relationship between leaf relative water content during reproductive stage water deficit and grain formation in rice , 2002 .

[26]  S. Fukai,et al.  Contribution of osmotic adjustment to grain yield in Sorghum bicolor (L.) Moench under water-limited conditions. I. Water stress before anthesis. , 1990 .

[27]  J. Zadoks.  A decimal code for the growth stages of cereals , 1974 .

[28]  H. Nguyen,et al.  Genetic analysis of osmotic adjustment in crop plants , 1999 .

[29]  R. C. Muchow,et al.  A critical evaluation of traits for improving crop yields in water-limited environments. , 1990 .

[30]  H. Nguyen,et al.  Leaf Water Content and Gas-Exchange Parameters of Two Wheat Genotypes Differing in Drought Resistance , 1990 .

[31]  B. Teulat,et al.  Comparative osmotic adjustments in barley and tetraploid wheats , 1997 .

[32]  R. Richards,et al.  Variation in temperate cereals in rainfed environments I. Grain yield, biomass and agronomic characteristics , 1994 .

[33]  H. Nayyar,et al.  Water Stress-induced Injury to Reproductive Phase in Chickpea: Evaluation of Stress Sensitivity in Wild and Cultivated Species in Relation to Abscisic Acid and Polyamines , 2005 .

[34]  I. Martı́n,et al.  Response of barley genotypes to terminal soil moisture stress: phenology, growth, and yield , 2007 .

[35]  J. Morgan,et al.  OSMOREGULATION AND WATER STRESS IN HIGHER PLANTS , 1984 .