Krishnamurthy Lakshmanan, Kashiwagi Junichi, Tobita Satoshi, Ito Osamu, Upadhyaya Hari D, Gowda Cholenahalli L L, Gaur Pooran M, Sheshshayee Madavalam S, Singh Sube, Vadez Vincent, Varshney Rajeev K
International Crops Research Institute for the Semiarid Tropics, Patancheru 502324, Andhra Pradesh, India.
Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
Funct Plant Biol. 2013 Dec;40(12):1350-1361. doi: 10.1071/FP13088.
Terminal drought is a major constraint to chickpea productivity. Carbon isotope discrimination (Δ13C), an integrator of plant behaviour influencing transpiration efficiency (TE), is an important component of yield under drought. The variation in Δ13C and its association with yield was assessed in the reference collection of chickpea germplasm. Drought stress reduced shoot biomass by 36-39% and grain yield by 23%. Mean Δ13C was low and the range of genetic variation was high under drought stress. Largely, high Δ13C accessions were early in flowering (40-50 days), moderate in shoot biomass, high in seed yields and high in harvest index (HI). Δ13C was positively correlated with seed yield in both the years under drought stress, only in 2008-09 under optimal irrigation. This positive association was very close with HI. Among the yield components, Δ13C was closely associated with pod numbers per unit area and seed size under drought stress. Path coefficients showed no direct association of Δ13C with grain yield but an indirect negative association through shoot biomass at maturity and a close positive association through HI. The closest association of HI or shoot biomass was seen in the maturity group of accessions that experienced the optimum terminal drought stress.
终末期干旱是鹰嘴豆产量的主要限制因素。碳同位素分辨率（Δ13C）是影响蒸腾效率（TE）的植物行为的一个综合指标，是干旱条件下产量的重要组成部分。在鹰嘴豆种质资源参考收集中评估了Δ13C的变异及其与产量的关联。干旱胁迫使地上部生物量降低了36%-39%，籽粒产量降低了23%。在干旱胁迫下，平均Δ13C较低，但遗传变异范围较高。在很大程度上，Δ13C值高的种质开花较早（40-50天），地上部生物量中等，种子产量高，收获指数（HI）高。在干旱胁迫下的两年以及仅在2008-2009年的最佳灌溉条件下，Δ13C与种子产量均呈正相关。这种正相关与收获指数密切相关。在干旱胁迫下，在产量构成因素中，Δ13C与单位面积荚数和种子大小密切相关。通径系数表明，Δ13C与籽粒产量无直接关联，但通过成熟时的地上部生物量呈间接负相关，通过收获指数呈紧密正相关。在经历最佳终末期干旱胁迫的种质成熟组中，收获指数或地上部生物量的相关性最为密切。
