In Vitro Safening of Bentazon by Melatonin in Sweetpotato (Ipomoea batatas)

Abstract

Weed competition is a main factor limiting sweetpotato [Ipomoea batatas (L.) Lam] production. Yellow nutsedge (Cyperus esculentus L.) is a problematic weed to control due to its ability to quickly infest a field and generate high numbers of tubes and shoots. Compounding this is the lack of a registered herbicide for selective postemergence control of yellow nutsedge. Research was conducted to evaluate the bentazon dose response of two sweetpotato cultivars and one advanced clone and to evaluate the plant hormone melatonin to determine its ability to safen bentazon post emergence. Bioassays using Murashige and Skoog (MS) media supplemented with melatonin (0.232 g a.i./L and 0.023 g a.i./L) and bentazon (0.24 g a.i./L) were conducted to evaluate the effect of bentazon on sweetpotato and to determine the interactive response of the Beauregard cultivar to bentazon and exogenous applications of melatonin. Beauregard swas the most tolerant cultivar and required dosages of bentazon that were two-times higher to cause the same injury compared with other cultivars. MS media containing melatonin and bentazon showed fewer injuries and higher plant mass than plants treated with bentazon alone. These results indicate that sweetpotato injury caused by bentazon may be reduced by melatonin.

Impact of tank mixing plant hormones with bentazon and mesotrione on sweetpotato injury and weed control

“…A similar response was reported by Caputo et al. (2020), where Beauregard had a greater tolerance to bentazon in vitro. The reduction in percentage plant injury when bentazon was tank mixed with melatonin could be associated with an improvement in herbicide tolerance and antioxidant activity.…”

“…Thus, the significant decrease in injury observed with some of the treatment combinations relative to mesotrione or bentazon alone is promising. When compared with results reported by Caputo et al (2020) in vitro, less injury due to bentazon was observed in Beauregard and Covington. Finally, the expected injury due to bentazon in the field might be less, since the plants would be hardier.…”

“…Caputo et al. (2020) reported a predicted dose of bentazon 2.5× higher for Beauregard than Covington to cause the same injury level in vitro environment. In a screen of sweetpotato germplasm to clomazone injury conducted by Harrison and Jackson (2011b), Beauregard had ∼10× greater tolerance than sensitive cultivars.…”

“…Additionally, Caputo et al. (2020) reported an improvement in sweetpotato tolerance to bentazon due to exogenous melatonin uptake in vitro .…”

Beneficial Effects of Exogenous Melatonin on Overcoming Salt Stress in Sugar Beets (Beta vulgaris L.)

“…Melatonin widely participates in nature as a ubiquitous molecule, and its biological activity occurs in unicellular organisms, fungi, animals, and plants [ 33 , 34 ]. Melatonin can enhance the tolerance of plants to abiotic stresses, such as low chilling, drought, herbicides, heavy metals, and salt [ 35 , 36 , 37 , 38 , 39 , 40 ]. Under salt conditions, exogenous application of melatonin regulates a variety of genes and physiological processes involved in resistance to salt stress in plants [ 41 , 42 , 43 , 44 , 45 , 46 ].…”