Skipping irrigation at pre- and post-anthesis stages influences grain yield and starch contents of bread wheat derived from synthetic or landraces

Authors: SHOKAT, SAJID - University Of Copenhagen; REHMAN ARIF, MIAN ABDUR - Nuclear Institute For Agriculture And Biology; QANDEEL WAHEED, MUHAMMAD - Nuclear Institute For Agriculture And Biology; LIU, FULAI - University Of Copenhagen; GUZMAN, CARLOS - Mendel University; Singh, Sukhwinder

Submitted to: Cereal Research Communications
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/24/2023
Publication Date: 11/10/2023
Citation: Shokat, S., Rehman Arif, M., Qandeel Waheed, M., Liu, F., Guzman, C., Singh, S. 2023. Skipping irrigation at pre- and post-anthesis stages influences grain yield and starch contents of bread wheat derived from synthetic or landraces. Cereal Research Communications. https://doi.org/10.1007/s42976-023-00461-8.
DOI: https://doi.org/10.1007/s42976-023-00461-8

Interpretive Summary: Globally, wheat is the major crop and staple diet of many countries. Water shortage at critical growth stages is the most common problem and resultantly grain yield is significantly compromised. Water stress at flowering stage reduces grain number and grain filling. Grain production is seriously hampered if water is not available at flowering and post-flowering stage. Plant genotypes enable to tolerate moisture stress at reproductive stage can contribute to sustainable wheat production in arid and semi-arid regions of the globe. Moisture stress at this stage reduces sucrose conversion into starch and resultantly less starch is accumulated. Starch is generally comprised of amylose and amylopectin and studies on two contrasting wheat genotypes reported a decrease in amylose contents under water stress conditions . This study indicating testing of fairly large germplasm for flowering stage moisture stress can help us to validate the previous findings by quantifying the values of amylose and amylopectin in large set of wheat germplasm. Current study was planned using diverse wheat germplasm obtained from Seeds of Discovery program of International Maize and Wheat Improvement Center (CIMMYT), Mexico. This germplasm has previously been tested for number of biotic and abiotic stresses and number of QTLs and marker-trait associations were identified . Further, a novel gene i.e., isoflavone reductase like was identified playing role in heat tolerance. This gene was further linked with physiology, phytohormones and antioxidants system to see its potential in marker-assisted selection (Shokat et al. 2021b). Previous reports indicate that genetic diversity can play a crucial role to sustain grain yield under different biotic and abiotic stresses. This study was planned to see the impact of flowering stage drought stress on starch contents i.e., amylose and amylopectin of bread wheat germplasm derived from landraces and synthetic derivatives. We constructed a hypothesis that reduction in grain yield is due to less accumulation of amylose and amylopectin in the grains.

Technical Abstract: This study aims to evaluate the role of genetic diversity originated from three way crosses of landraces and synthetic bread wheat derivatives attempted with elite cultivars to identify the genotypes having better grain yield as well as better starch contents under flowering stage drought stress. In total, 50 genotypes comprised of three commercial checks were grown in the fields of International Maize and Wheat Improvement Center (CIMMYT), following alpha-lattice design with two replications. Drought stress was imposed by stopping the irrigation before anthesis and post-anthesis stages. Different traits related to physiological adaptations, earliness, grain yield and starch contents were decreased under drought stress except amylose which increased significantly. Canopy temperature depression and traits measured before imposing the stress were not affected by drought stress. Further, we identified strong correlation of grain yield with plant height, normalized difference in vegetation index, plant maturity, spike length, grain number and thousand grain weight but negative with canopy temperature depression. Non-significant correlation of amylose and amylopectin was recorded with grain yield. Results revealed that genetic diversity derived from landraces and synthetic bread wheat can improve grain yield and starch contents but simultaneousimprovement of both is elusive.