Characterization of the Novel Tomato Mutant HRT, Resistant to Acetolactate Synthase–Inhibiting Herbicides

Abstract

The tomato mutant line HRT was obtained by ethyl methanesulfonate seed mutagenesis of the commercial tomato line M82. Greenhouse studies were conducted to determine whole-plant response to the imidazolinone herbicides imazamox, imazapic, and imazapyr; pyrithiobac-sodium (a herbicide from the pyrimidinylthiobenzoic acid group); and propoxycarbazone sodium (sulfonylaminocarbonyltriazolinone group). The mutant was highly resistant to imazamox, imazapic, and imazapyr, but did not differ from M82 in its response to the sulfonylurea herbicides Envoke (trifloxysulfuron), Monitor (sulfosulfuron), and Glean (chlorsulfuron). Equip (foramsulfuron), a sulfonylurea herbicide, was toxic to M82 but less so to HRT plants. Under field conditions, HRT showed high resistance to imazapic and imazapyr. The herbicides at a rate of 144 g ai ha−1did not cause any reduction in HRT plant vigor, development, or yield. Results of greenhouse and field experiments demonstrated high Egyptian broomrape–control efficacy with the imidazolinone herbicides imazapic and imazapyr. Two imazapic applications of 9.6 or 14.4 g ai ha−1and three applications of 4.8 g ai ha−1in pot experiments completely prevented appearance of broomrape shoots aboveground. Three and four applications of the same herbicides in the field at a rate of 12 or 24 g ai ha−1completely prevented shoot appearance without any yield losses. Single imazapic application as high as 144 g ai ha−1did not damage the plants or reduce HRT yield.

Recent research progress in combatting root parasitic weeds

“…In four countries of Eastern Africa, imazapyr-coated seeds of other IR maize varieties supported significantly fewer Striga emergence and showed more grain yield than commercial varieties without the herbicide coating [194]. In Israel, application of imazapic and imazapyr during tomato cultivation using an IR tomato mutant demonstrated high P. aegyptiaca control efficacy [195].…”

The Effects of Herbicides Targeting Aromatic and Branched Chain Amino Acid Biosynthesis Support the Presence of Functional Pathways in Broomrape

“…M82 seeds were obtained from Tarsis Agricultural Chemicals Ltd., Israel. HRT, a tomato mutant that is highly resistant to imidazolinone herbicides, was obtained by ethyl methanesulfonate (EMS) mutagenesis ( Dor et al, 2016 ). Broomrape seeds were collected from Egyptian broomrape inflorescences parasitizing tomato grown in Kibbutz Beit Ha’shita, Israel.…”

“…Broomrape seeds were stored in the dark at 4°C until use. Tomato plants were grown in 2-l pots using medium-heavy clay–loam soil containing broomrape seeds at a concentration of 15 ppm (15 mg seed kg -1 soil, ∼2250 seed kg -1 ) as described in Dor et al (2016) .…”

“…Imazapic and imazapyr (38.4 g a.i. ha -1 ) were applied on HRT plants—tomato mutants that are highly resistant to imidazolinone herbicides ( Dor et al, 2016 ). Non-treated plants were used as a control.…”

Synthesis and Herbicidal Activity of O‐(2,6‐Bis(4,6‐dimethoxypyrimidin‐2‐yloxy) benzoyl)oxime 3‐Trifluoromethylacetophenone

“…By binding to ALS enzyme, herbicidal ALS inhibitors could block the substrate channel of ALS, leading to the inactivation of ALS and eventually weeds death . To now, more than 50 different ALS‐inhibiting herbicides have been marketed and can be classified into 5 different classes, including sulfonylureas, pyrimidylsalicylates, imidazolinones, triazolopyrimidines, and sulfonamides . Among these different ALS‐inhibiting herbicides, pyrimidylsalicylates are mainly used for control of weeds in paddy fields and cotton fields .…”