P. K. Aggarwal, R. A. Fischer, and S. P. Liboon, Source sink relations and effects of post anthesis canopy defoliation in wheat at low latitudes, J. Agric. Sei, vol.114, p.99, 1990.

I. Aranjuelo, L. Cabrera, R. Bosquet, J. C. Morcuende, S. Avice et al., Does ear C sink strength contribute to overcoming photosyn thetic acclimation of wheat plants exposed to elevated CO 2 ?, J. Exp. Bot, vol.62, p.3969, 2011.

J. L. Araus and L. Tapia, Photosynthetic gas exchange characteristics of wheat flag leaf blades and sheaths during grain filling, Plant Physiol, vol.85, p.673, 1987.

J. L. Araus, H. R. Brown, A. Febrero, J. Bort, and M. D. Serret, Ear photosynthesis, carbon isotope discrimination, and the contribution of respiratory CO 2 to differences in grain mass in durum wheat, Plant, Cell Environ, vol.16, p.392, 1993.

I. M. Atkins and M. J. Norris, The influence of awns on yield and certain morphological characters of wheat, Agron. J, vol.47, 1955.

R. B. Austin and J. Edrich, Effects of ear removal on pho tosynthesis, carbohydrate accumulation and on distribution of assimilated 14 C in wheat, Ann. Bot, vol.39, p.152, 1975.

F. Bidinger, R. B. Musgrave, and R. A. Fischer, Contribu tion of stored pre anthesis assimilate to grain yield in wheat and barley, Nature, vol.270, p.433, 1977.

W. M. Blacklow, B. Darbyshire, and P. Pheloung, Fruc tans polymerized and de polymerized in the internodes of winter wheat as grain filling progressed, Plant Sci. Lett, vol.36, p.218, 1984.

D. J. Carr and I. F. Wardlaw, The supply of photosyn thetic assimilates to the grain from the flag leaf and ear of wheat, Aust. J. Biol. Sci, vol.18, p.719, 1965.

L. T. Evans, J. Bingham, P. Jackson, and J. Sutherland, Effect of awns and drought on the supply of photosynthate and its distribution within wheat ears, Ann. App. Biol, vol.70, p.76, 1972.

L. T. Evans, I. F. Wardlaw, and R. A. Fischer, Crop Physiology: Some Case Histories, pp.101-149, 1980.

G. D. Farquhar, J. R. Ehleringer, and K. T. Hubick, Car bon isotope discrimination and photosynthesis, Annu. Rev. Plant Physiol. Plant Mol. Biol, vol.40, p.537, 1989.

J. N. Gallagher, P. V. Biscoe, and B. Hunter, Effects of drought on grain growth, Nature, vol.264, p.542, 1976.

T. Gebbing and H. Schnyder, C labelling kinetics of sucrose in glumes indicates significant refixation of respiratory CO 2 in the wheat ear, Aust. J. Plant Physiol, vol.28, issue.13, p.1053, 2001.

M. Hafsi, P. Monneveux, O. Merah, and A. Djekoune, Discrimination isotopique du carbone et rendement du bl e dur dans les hautes plaines s etifiennes, vol.37, p.43, 2001.

L. Hannachi, E. Del, and P. Gate, Nitrogen and car bon isotope composition of wheat grain: alteration due to sink source modifications at flowering, Rapid Commun. Mass Spect, vol.19, p.986, 1996.

T. Kramer and F. A. Didden, The influence of awns on grain yield and kernel weight in spring wheat. (Triticum aestivum L.), Cereal Res. Commun, vol.9, p.30, 1981.

D. E. Martinez, V. M. Luquez, C. G. Bartoli, and J. J. Guiam, Persistence of photosynthetic components and photo chemical efficiency in ears of water stressed wheat (Triticum aestivum), Physiol. Plant, vol.119, p.525, 2003.

M. L. Maydup, M. Antonietta, J. J. Guiam, C. Graciano, J. R. et al., The contribution of ear photosynthesis to grain filling in bread wheat (Triticum aes tivum L.). Field Crops Res, vol.119, p.58, 2010.

O. Merah, E. Del, and P. Monneveux, Relationships between carbon isotope discrimination, dry matter produc tion, and harvest index in durum wheat, J. Plant Physiol, vol.158, p.729, 2001.

O. Merah, E. Del-eens, B. Teulat, and P. Monneveux, Association between yield and carbon isotope discrimination value in different organs of durum wheat under drought, J. Agron. Crop Sci, vol.188, p.434, 2002.

P. Monneveux, D. Rekika, E. Acevedo, and O. Merah, Effect of drought on leaf gas exchange, carbon isotope dis crimination, transpiration efficiency and productivity in field durum wheat genotypes, Plant Sci, vol.170, p.872, 2006.

E. Ninou, J. T. Tsialtas, C. A. Dordas, and D. K. Papakosta, Effect of irrigation on the relationships between leaf gas exchange related traits and yield in dwarf dry bean grown under Mediterranean conditions, Agric. Water Manag, vol.116, p.241, 2013.

T. Oweis, M. Pala, and J. Ryan, Stabilizing rainfed wheat yields with supplemental irrigation and nitrogen in Mediterra nean climate, Agron. J, vol.90, p.681, 1998.

J. A. Palta, T. Kobata, N. C. Turner, and I. R. Fillery, Remobilization of carbon and nitrogen in wheat as influenced by post anthesis water deficits, Crop Sci, vol.34, p.124, 1994.

A. R. Saghir, A. R. Khan, and W. W. Worzella, Effects of plant parts on the grain yield, kernel weight, and plant height of wheat and barley, Agron. J, vol.60, p.97, 1968.

R. Sanchez-bragado, A. Elazab, B. Zhou, M. D. Serret, J. Bort et al., Con tribution of the ear and the flag leaf to grain filling in durum wheat inferred from the carbon isotope signature: Genotypic and growing conditions effects, J. Integr. Plant Biol, vol.56, p.454, 2014.

P. Seidel, Tolerance responses of plants to stress. The unused reserve in plant protection, Plant Resp. Dev, vol.44, p.89, 1996.

E. A. Tambussi, J. Bort, J. J. Guiam, S. Nogues, and J. L. Ar, The photosynthetic role of ears in C3 cereals: metabolism, water use efficiency and contribution to grain yield, Crit. Rev. Plant Sci, vol.26, p.16, 2007.

G. N. Thorne, Distribution between parts of the main shoot and the tillers of photosynthate produced before and after anthesis in the top three leaves of main shoots of Hobbit and Maris Huntsman winter wheat, Ann. App. Biol, vol.101, p.559, 1982.

X. L. Wu and W. K. Bao, Statistical analysis of leaf water use efficiency and physiology traits of winter wheat under drought condition, J. Integr. Agric, vol.11, p.89, 2012.

H. L. Xu and R. Ishii, Wheat cultivar differences in pho tosynthetic response to low soil water potentials. 1. Mainte nance of photosynthesis and leaf water potential, Jpn. J. Crop Sci, vol.65, p.517, 1996.

Z. Z. Xu and G. S. Zhou, Effects of water stress and noc turnal temperature on carbon allocation in the perennial grass, Leymus chinensis, Physiol. Plant, vol.123, p.280, 2005.

X. Xu, H. Yuan, S. Li, and P. Monneveux, Relationship between carbon isotope discrimination and grain yield in spring wheat under different water regimes and under saline conditions in the Ningxia Province, 2007.

, J. Agron. Crop Sci, vol.193, p.434

J. Yang and J. Zhang, Grain filling of cereals under soil drying, New Phytol, vol.169, p.236, 2006.

Y. Zhang, Y. Zhang, Z. Wang, and Z. Wang, Characteris tics of canopy structure and contributions of non leaf organs to yield in winter wheat under different irrigated conditions, Field Crops Res, vol.123, p.195, 2011.

G. X. Zhu, D. J. Midmore, B. J. Redford, and D. F. Yule, Effect of timing of defoliation on wheat (Triticum aestivum L.) in central Queensland. 1. Crop response and yield, Field Crops Res, vol.88, p.226, 2004.

L. Zhu, S. H. Li, Z. S. Liang, X. Xu, and Y. Li, Relation ship between carbon isotope discrimination, mineral content and gas exchange parameters in vegetative organs of wheat grown under three different water regimes, J. Agron. Crop Sci, vol.196, p.184, 2010.