Performance of Bt-susceptible and -heterozygous genotypes of Spodoptera frugiperda (J.E. Smith) possessing single- or dual-gene resistance alleles in sequential feedings of non-Bt and Cry1A.105/Cry2Ab2 maize leaf tissues.

We simulated larval feeding behavior in seed blends of non-Bt and Bt maize to determine if seed blends create more favorable conditions for heterozygous-resistant insects over their Bt-susceptible counterparts. Survival, growth, development, and progeny production of four genotypes of the fall armyworm, Spodoptera frugiperda, Bt-susceptible (aabb), Cry1A.105 heterozygous resistant (Aabb), Cry2Ab2 heterozygous resistant (aaBb), and Cry1A.105/Cry2Ab2 heterozygous resistant (AaBb), were evaluated in eight feeding sequences (Seq 1-8) of non-Bt and MON89034 Bt maize leaf tissue expressing the Cry1A.105 and Cry2Ab2 proteins. We report variation in the performance of the four genotypes across the feeding sequences and biological parameters measured. Three heterozygous genotypes generally outperformed the susceptible genotype in larval survival, pupation rate, pupal weight, and progeny production. The performance was greater for Aabb over aaBb, AaBb over Aabb or aaBb, in two of the feeding sequences. The findings of this study could have important implications in assessing the risk of seed blends as refuge plantings for Bt crop resistance management where resistance in the target pest is not functionally recessive.

Synthesis and antifungal activity of benzamidine derivatives carrying 1,2,3-triazole moieties.

Eighteen novel benzamidine derivatives containing 1,2,3-triazole moieties were synthesized. The in vitro and in vivo fungicidal acitivities of the title compounds and the arylamidine intermediates against Colletotrichum lagenarium and Botrytis cinerea were tested. The synthesized benzamidines exhibited weak antifungal activities in vitro against the tested fungi, but some of the compounds showed excellent activities in vivo to the same strains. Among the compounds tested, 9b showed 79% efficacy in vivo against C. lagenarium at a concentration of 200 µg/mL, and the efficacy of compound 16d (90%) toward the same strain was even superior than that of the commercial fungicide carbendazim (85%).

Matrine can be absorbed and transmitted bidirectionally to defend against aphids (Hemiptera: Aphididae) on wheat and pepper.

BACKGROUND: Although matrine is widely used, its absorption and transport mechanisms in crops remain unexplored. In this study, three methods including foliar application, hydroponics and seed immersion were used to investigate whether matrine molecules could enter into plants through different channels, and to further resolve its transport characteristics. The systemic activity of matrine also was evaluated. RESULT: Matrine was quickly absorbed and transported downwards after the leaves of wheat or peppers were treated, and also accumulated and transmitted upwards by roots. It was not only absorbed by seeds, but also appeared continuously in young roots and leaves in both plants for nearly 20 days. There were some differences in the uptake and conduction of matrine between pepper and wheat: matrine concentrated in pepper upper leaves with less delivered downwards to roots than in wheat, and also transduction of matrine in pepper lower leaves upwards to upper leaves was less than in wheat. Matrine had systemic activity, with LC50 of 361.99 and 904.24 µg·mL-1 against Rhopalosiphum padib on wheat and Myzus persicae (Sulzer) on pepper plants at 48 h, separately. CONCLUSION: Matrine can be absorbed by the roots, seeds and leaves of plants, and transmitted bidirectionally to any organs, presenting satisfactory systemic poisoning activity against aphids. It is of great significance to develop new formulation products of matrine and promote its commercialized value. © 2023 Society of Chemical Industry.

Synthesis and field evaluation of the sex pheromone analogues to soybean pod borer Leguminivora glycinivorella.

In order to develop efficient lures for soybean pod borer Leguminivora glycinivorella (Matsumura) in China, (E,E)-8,10-dodecadienyl acetate (EE-8,10-12:Ac), the main component of the pheromone of L. glycinivorella, and 12 structurally-related compounds were synthesised in good overall yields, regiospecificities, and stereo-selectivities via coupling reactions catalysed by Li2CuCl4. The effect of different synthetic compounds, alone or in combination with EE-8,10-12:Ac, on numbers of captured L. glycinivorella males was evaluated. EE-8,10-12:Ac, (E)-10-dodecenyl acetate (E-10-12:Ac), (E)-8-dodecenol (E-8-12:OH), tetradecyl acetate (14:Ac), and (Z)-9-tetradecenyl acetate (Z-9-14:Ac) alone displayed different attractiveness to L. glycinivorella males. 14:Ac, E-8-12:OH, E-10-12:Ac, (E,E)-8,10-dodecadienal (EE-8,10-12:Ald), (E)-8-dodecenal (E-8-12:Ald), (E)-10-dodecenal (E-10-12:Ald) and Z-9-14:Ac all showed a synergistic effect to EE-8,10-12:Ac at certain dosages. The binary mixtures of EE-8,10-12:Ac and E-10-12:Ald, Z-9-14:Ac,14:Ac, E-8-12:Ald, EE-8,10-12:Ald, E-8-12:OH, or E-10-12:Ac in suitable ratios give 17.00-, 10.98-, 10.67-, 6.73-, 5.54-, 4.30- and 4.50-fold increases in trap catch, respectively, over the standard pheromone lure, and as novel pheromone blends, demonstrated potential use in pheromone traps to monitor or control L. glycinivorella populations in China.

Europium(III) functionalized 3D covalent organic framework for quinones adsorption and sensing investigation.

Chemical functionalization is essential for tuning the physical-chemical characters and broadening the potential applications of covalent organic frameworks (COFs). Based on the multistep postsynthetic modification strategy, Eu (III)-functionalized 3D COF (Eu-3D-COF) was prepared by grafting of Eu (III) onto the carboxyl-funtionalized 3D-COF (COOH-3D-COF). With micropores dominated microspheres structure, Eu-3D-COF exhibited superior adsorption affinity to multi-rings contained quinones based on the π-π interaction, coordination and hydrogen-bonding interactions, especially to 9,10-phenanthrenequinone (PQ) whose adjacent carbonyl oxygens resulting preferable synergistic chelation interaction with Eu(III) was responsible for the maximum adsorption capacity, which was confirmed by instrumental characterizations. The adsorptivity of Eu-3D-COF was apparently improved in comparison with COOH-3D-COF. More importantly, grafting of Eu(III) turned on the fluorescence of the COF, making Eu-3D-COF also a superior chemosensor for sensing application. Its fluorescent can be selectively quenched by quinones, especially by PQ based on the PQ-Eu and PQ-COF interactions co-dominated energy transfer. Therefore, both as an adsorbent and a chemosensor, the multi-functional COF was explored for quinones adsorption and sensing detection investigation in detail. Eu-3D-COF has promising application potentials for hazardous quinones adsorption and sensing detection, which also opens new perspectives for inorganic-organic 3D-COF construction and multi-functional applications.