Priming with Humic Acid to Reverse Ageing Damage in Soybean [Glycine max (L.) Merrill.] Seeds

Abstract

Soybean seed vigour declines with increase in storage duration, due to ageing, which can be alleviated through seed priming. The objective of this study was to investigate the effects of Humic acid (HA) priming on germination, vigour and seedling performance under laboratory and greenhouse conditions with two soil moisture level [50% and 80% field capacity (FC)]. Seeds stored for 12 months having 60% germination were primed either with 0.2 g/L HA solution or distilled water (hydro-primed) at 25 °C for 1, 3, 5 and 7 h. Non-primed dry seeds were used as control, giving nine treatment combinations. Various germination traits [mean germination time (MGT), final germination percentage (FG%), germination rate index (GRI), seedling emergence percentage (SEP)], mean emergence time (MET), seedling quality traits [seedling vigor index (SVI), shoot length, root length, root volume], antioxidant enzyme activities [catalase (CAT), peroxidase (POD)], lipid peroxidation [malondialdehyde (MDA)] and electrical conductivity (EC) were determined. A germination test in the laboratory was conducted as single factor (nine priming treatments), while the greenhouse experiment was conducted as two factors [2 soil moisture level (50 and 80% FC) and 9 priming treatments]. The results indicated that seeds primed with HA for 5 h was able to reinstate the CAT activities (25%), POD activities (50%) and reduced EC (51%) and MDA content (40%) compared with non-primed seeds, reduced the MET (from 4.3 to 3.5 days), increased FG% (from 62% to 71%), GRI (15.6–21.1) and SEP (from 35% to 54%) and (from 60% to 72%) at 50% FC level and 80% FC level, respectively. A strong negative correlation (r = −0.80 **) was found between MDA content and GRI, while CAT and POD activities had positive correlation with GRI r= 0.67 ** and r = 0.56 **, respectively. Thus, priming with 0.2 g/L HA for 5 h improved the vigour of minimally deteriorated soybean seeds resulting in increased emergence with more uniform field establishment.

Bio-Priming of Soybean with Bradyrhizobium japonicum and Bacillus megaterium: Strategy to Improve Seed Germination and the Initial Seedling Growth

“…Seed bio-priming was conducted using the aforementioned liquid bacterial suspensions at 25 °C for 5 h, under dark conditions. After priming, seeds were rinsed thoroughly with distilled water, and dried on sterile filter paper at room temperature for 72 h [ 52 ].…”

Effect of biofertilizers and humic acid on vegetative growth parameters in Sat Kara (Citrus macroptera) under soil media conditions

“…Ali et al (2020) reported that Humic acid exhibited most impacts on the seedling vigour index in sorghum plant. According to Weerasekara et al (2021) priming soybean seeds treated with humic acid for 3,5 and 7 hours which enhances the germination with the increase of time and increases the seedling vigour index as compared to control.…”

The Effect of ellagic acid on physiological traits of plants grown from normal and aged soybean seeds

“…has a special function in supplying the world's protein and calorie needs (Messina, 2022). One of the main issues with soybean seed storage is thought to be seed aging (Weerasekara et al, 2021). Membrane degradation due to lipid peroxidation is the rst event that occurs during seed aging.…”