Post-anthesis photosynthetic attributes and N-P-K status of standard and emmer wheats respond differently to nitrogen supply

Abstract

Impact of nitrogen (N) supply on photosynthesis and N, P, and K status of wheat, particularly ancient wheats lacks clarity. Hence, clarification of post-anthesis photosynthesis and N, P, and K status of ancient emmer compared to the improved durum and bread wheats was aimed at. Five field-grown ancient emmer, one improved durum and an improved bread wheat exposed to a wide range of N fertilizer (i.e. 0, 25, 50, and 75 kg ha−1 N) were tested in two consecutive years. Chlorophyll and carotenoids concentrations of the emmer and improved wheats were increased by 39–63% and 29–45%, respectively in response to N supply. Mesophyll conductance and net photosynthetic rate of the improved bread wheat were increased by 150% and 60%, respectively, with increase in N supply, but those of the emmer wheats were decreased in response to the medium (0–43%) and high N (0–37%) supplies. Emmer wheat out-numbered the improved wheats in terms of mesophyll conductance and net photosynthetic rate under the low N supply but the reverse was true with the high N supply. Leaf (1–2.2, 3.2–7.7, and 16.8–35 mg g−1, respectively) and grain (2.38–6.4, 5.6–12.1, and 20.5–28.9 mg g−1, respectively) P, leaf N, and grain K concentrations responded positively to the N supply and emmer wheats equaled or exceeded those of the improved wheats particularly when grown in the absence of high N supplies. The presented data indicates that ancient emmer wheats are potent to be employed to incorporate nutrient-acquiring traits into the modern wheats.