caa a22 4500 606218041 CHVBK 20210128101110.0 cr unu---uuuuu 210128e20150401xx s 000 0 eng 10.1007/s11104-014-2338-8 doi (NATIONALLICENCE)springer-10.1007/s11104-014-2338-8 Tolerant pearl millet ( Pennisetum glaucum (L.) R. Br.) varieties to low soil P have higher transpiration efficiency and lower flowering delay than sensitive ones [Elektronische Daten] [Francesca Beggi, Hamidou Falalou, Andreas Buerkert, Vincent Vadez] Background and aim: In the West African Sahel low soil phosphorus (P) and unpredictable rainfall are major interacting constraints to growth and grain yield of pearl millet. Investigating the relationship between transpiration and final yield under the combined effect of water and P stress is fundamental to understand the underlying mechanisms of tolerance and improve breeding programs. Methods: We conducted two lysimeter trials using 1m long PVC tubes (35cm diameter) filled with a P poor Sahelian soil mimicking soil profiles to assess grain and stover yield, and water use of 15 pearl millet genotypes grown under different P (no P supply or addition of 1.5g P tube−1) and water (well watered or terminal water stress) regimes. In experiment 2 transpiration was measured twice a week from tube weight differences, and transpiration efficiency (TE) was calculated as dry matter (DM) produced per kg of water transpired. Results: Low soil P delayed flowering, and more so in sensitive genotypes. Later flowering of genotypes sensitive to low P made them more sensitive to terminal water stress. Under P limiting soil, genotypes tolerant and sensitive to low P used similar amounts of water (19.8 and 21.7kg water plant−1, respectively). However, tolerant lines transpired less water prior to anthesis (8.8kg water plant−1) leaving more water available for grain filling (11kg water plant−1) while sensitive lines used 14.4kg water plant−1 pre-anthesis, leaving only 7.2kg water plant−1 for grain filling. Low soil P decreased grain yield by affecting seed size at harvest and its damage during seed filling overrode the effect of seed size at sowing. Grain yield was positively correlated with water extracted after anthesis. TE was enhanced by P supply, especially in sensitive lines, and TE was higher in tolerant than in sensitive genotypes under low soil P. Conclusions: Pearl millet plants tolerant to low P were more resistant to the delay of flowering caused by low P soil and they presented higher transpiration efficiency. The pattern of transpiration was important to cope with terminal water stress under different levels of P availability. Higher transpiration after anthesis, resulting from conservative water mechanism pre-anthesis (higher TE) and possibly by a shorter delay in flowering under low soil P, enhanced grain yield. The Author(s), 2014 Water stress nationallicence Lysimeter nationallicence Transpiration efficiency nationallicence Water use nationallicence Beggi Francesca Organic Plant Production and Agroecosystems Research in the Tropics and Subtropics, University of Kassel, Witzenhausen, Germany aut Falalou Hamidou Sahelian Center, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Niamey, Niger aut Buerkert Andreas Organic Plant Production and Agroecosystems Research in the Tropics and Subtropics, University of Kassel, Witzenhausen, Germany aut Vadez Vincent Crop Physiology Laboratory, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), 502324, Patancheru, Telangana, India aut Plant and Soil Springer International Publishing 389/1-2(2015-04-01), 89-108 0032-079X 389:1-2<89 2015 389 11104 https://doi.org/10.1007/s11104-014-2338-8 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11104-014-2338-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Beggi Francesca Organic Plant Production and Agroecosystems Research in the Tropics and Subtropics, University of Kassel, Witzenhausen, Germany aut NATIONALLICENCE 700 1- Falalou Hamidou Sahelian Center, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Niamey, Niger aut NATIONALLICENCE 700 1- Buerkert Andreas Organic Plant Production and Agroecosystems Research in the Tropics and Subtropics, University of Kassel, Witzenhausen, Germany aut NATIONALLICENCE 700 1- Vadez Vincent Crop Physiology Laboratory, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), 502324, Patancheru, Telangana, India aut NATIONALLICENCE 773 0- Plant and Soil Springer International Publishing 389/1-2(2015-04-01), 89-108 0032-079X 389:1-2<89 2015 389 11104