Relationships between Transpiration Efficiency and Carbon Isotope Discrimination in Chickpea (C. arietinum L) uri icon

abstract

  • Since major cultivation areas of chickpea (Cicer arietinumL.) are in the arid and semi-arid zones, terminal droughtis one of the major constraints limiting its productivity.Simple analytical crop models can help in identifying keystrategies to improve the chickpea productivity underdrought. For example, Passioura (1977) had proposedthat the yield is a function of transpiration, transpirationefficiency (TE) defined as the biomass production perunit of water transpired, and harvest index. As improvementof TE means maximization of crop production per unit ofwater use, it is one of the important components forimproving the drought resistance (Turner et al. 2001).Although TE had been recognized as a highly relevanttrait, so far very little research effort had been madetowards field screening for it, especially due to thedifficulties in measuring TE in any screening method.The method developed by Farquhar et al. (1982) forestimating TE through measuring the discriminationagainst 13C by leaves during photosynthesis, andestablishment of a close relationship between the carbonisotope discrimination (?13C) and TE in many legumecrops such as bean, cowpea, groundnut, and soybean hasprovided an useful method of screening. This gave scopefor using ?13C as an indirect screening tool for TE. Inchickpea, however, there is no information available onthe relationship between ?13C and TE. The majorobjectives of this study were to check if there are anyvariations available for ?13C, to investigate the relationshipbetween ?13C and TE, and to ascertain the possibility ofusing ?13C as a surrogate for TE measurements

publication date

  • 2006