Water deficit stress alleviation by bio-formulated native mycorrhizal species for wheat grown in a saline calcareous soil

Z.A. Abdel-Salam¹*, M.A. Abouzeid², M.M. El-Shazly¹ and D.A.M. Abdou²

¹Department of Soil Fertility and Microbiology, Desert Research Center, Cairo, Egypt
²Department of Microbiology, Faculty of Science, Ain Shams University, Cairo, Egypt
*Correspondence: zenabahmed5@gmail.com

Abstract:

Arbuscular mycorrhizal fungi (AMF) are a genus of obligatory root biotrophs that can develop mutualistic symbioses with most terrestrial plants. This study aimed to investigate the impact of three different isolates of AMF (Acaulospora spinosa [M1], Glomus ambisporum [M2], and Scutellospora heterogama [M3]) isolated from native environments and three carriers (biochar, alginate, and polyacrylate) on wheat (Triticum aestivum L.) grown in a saline calcareous soil in conditions of water deficit. In a pot experiment, reduced amounts of water were applied at intervals of 4, 8, and 12 days, while in a field experiment, the intervals were 1, 2, and 3 weeks (W1, W2, and W3). By analyzing the chlorophyll index and dry weight data from the pot experiment, it was revealed that two AMF isolates (M1 and M2), along with two carriers (biochar and alginate), showed promising results in stimulating wheat growth. Based on these findings, a field validation experiment was conducted to further evaluate the effects of these isolates and carriers. The wheat plants subjected to water deficit stress exhibited improved vegetation characteristics, grain yield, nutrient uptake, and colonization percentage when treated with the AMF isolate M2 formulated on biochar. For instance, under W2 conditions without any mycorrhiza or carrier, the grain yield was recorded at 6,600 kg ha^-1. However, with the inoculation of M2-biochar at the same W2 level, the yield significantly increased to 9110 kg ha^‑1. The study concluded that AMF formulated on biochar outperformed other carriers, leading to enhanced wheat growth under water stress conditions.

Key words:

Wheat cultivars exposed to high temperature at onset of anthesis for yield and yield traits analysis

R. Goher and M. Akmal*

Department of Agronomy, Faculty of Crop Production Sciences, The University of Agriculture, Peshawar-25130, Pakistan
*Correspondence: akmal@aup.edu.pk

Abstract:

Temperature fluxes at some critical growth stages adversely affect the crop yield. Heat stress (HS) of limited duration shows mild to marked effects on crop yield. The study focused on evaluating HS of limited durations on wheat crop effective from anthesis. Four wheat cultivars (Pirsabak-2005, Pakhtunkhwa-2015, Pakistan-2013, and DN-84) and three advanced lines (P-2, P-12, and P-18) were subjected to HS for 48, 72, and 96 h evaluating changes in the yield and yield contributing traits. The experiment was conducted in a randomized complete block design during 2017–18 and 2018–19 at Agronomy Research Farm, the University of Agriculture Peshawar Pakistan. At the onset of anthesis, plants were exposed to HS in the plastic tunnel for limited durations. The temperature inside and outside tents was recorded periodically. The mean across the years showed a significant effect on yield traits by HS imposition at anthesis stage. The mean data across the two years showed a significant effect of HS on yield and yield contributing traits. In comparison with control, spike weight (g) reduced by 29, 40, and 49% under limited HS of 48, 72, and 96 h, respectively. Grains per spike were decreased by 45, 61, and 69% and grain weight by 29, 36, and 45% from control to imposed HS of 48, 72, and 96 h, respectively. Overall grain yield decreased by 44, 61, and 70% upon exposed to 48, 72, and 96 h of HS, respectively. The differences among the cultivars for yield and yield contributing traits were different under various HS conditions. The study concluded that HS effective from anthesis has an adverse effect on grain weight and number and hence the grain yield. Among the cultivars, Pakistan-2013 showed better resistance to HS of limited duration when exposed at the anthesis stage of the crop growth.

Key words:

grain number, grain weight, heat stress, heat-stress duration, wheat yield