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Leaf transpiration plays a role in phosphorus acquisition among a large set of chickpea genotypes

Pang, Jiayin, Zhao, Hongxia, Bansal, Ruchi, Bohuon, Emilien, Lambers, Hans, Ryan, Megan H., Siddique, Kadambot H.M.
Plant, cell and environment 2018 v.41 no.9 pp. 2069-2079
Cicer arietinum, breeding programs, chickpeas, ferric phosphate, genetic background, genetic variation, growth performance, inorganic phosphorus, leaves, mass flow, nutrient use efficiency, photosynthesis, plant growth, rivers, sand, sandy soils, transpiration
Low availability of inorganic phosphorus (P) is considered a major constraint for crop productivity worldwide. A unique set of 266 chickpea (Cicer arietinum L.) genotypes, originating from 29 countries and with diverse genetic background, were used to study P‐use efficiency. Plants were grown in pots containing sterilized river sand supplied with P at a rate of 10 μg P g⁻¹ soil as FePO₄, a poorly soluble form of P. The results showed large genotypic variation in plant growth, shoot P content, physiological P‐use efficiency, and P‐utilization efficiency in response to low P supply. Further investigation of a subset of 100 chickpea genotypes with contrasting growth performance showed significant differences in photosynthetic rate and photosynthetic P‐use efficiency. A positive correlation was found between leaf P concentration and transpiration rate of the young fully expanded leaves. For the first time, our study has suggested a role of leaf transpiration in P acquisition, consistent with transpiration‐driven mass flow in chickpea grown in low‐P sandy soils. The identification of 6 genotypes with high plant growth, P‐acquisition, and P‐utilization efficiency suggests that the chickpea reference set can be used in breeding programmes to improve both P‐acquisition and P‐utilization efficiency under low‐P conditions.