Wheat production worldwide is severely challenged by different pest and pathogen species, and misguided application of chemicals in farming significantly stimulates crop invaders to develop insecticide resistance. The growing desire for sustainable agriculture has promoted the breeding of wheat cultivars with durable pests and diseases resistance tolerance traits, which have become increasingly imperative for wheat production. Various genetic breeding techniques, including transgenic breeding, molecular marker-assisted breeding, molecular breeding with gene pyramiding, gene silencing, and gene editing, have been successfully deployed into wheat cultivar improvement, and have significantly promoted the process of breeding cultivars with multiple substantial resistance traits. Although the success of practical applications of some of these resistant wheat cultivars in farming has suggested that these approaches are effective strategies for combating fungal diseases and herbivorous insects, there remains significant challenges for wheat molecular breeding programs. Thus, this review illustrates and summarizes the recent advances and drawbacks related to the measures associated with molecular breeding in common wheat cultivar improvement.

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Changing electrical environments can influence the performance of herbivorous insects and adversely affect their control strategies. The diamondback moth, Plutella xylostella (L.), is a pest that devastates cruciferous vegetables. An age–stage, two-sex life table of P. xylostella over multiple generations was established to describe the effect of varying high-voltage electrostatic field (HVEF) exposure on their performance after the age-cohort eggs were exposed to HVEF at an intensity of 5.0 kV/cm for different durations. The results show that direct HVEF exposure adversely affected the population dynamics parameters of P. xylostella over multiple generations. In particular, the net reproduction rate, intrinsic natural increase rate, and finite increase rate of the P. xylostella population significantly decreased in the third and fifth generations under HVEF exposure for 10 min, while the mean generation time and doubling time significantly increased. Similarly, HVEF exposure for 10 min rapidly reduced the survival rate of adult P. xylostella in the first generation, and subsequently, it declined evenly and slowly. Meanwhile, the fecundity parameters of P. xylostella revealed that HVEF exposure for 10 min had the strongest inhibition effect on reproduction over five consecutive generations. In addition, HVEF exposure significantly increased the superoxide dismutase activity to produce extra hydrogen peroxide; however, increased catalase and peroxidase activity or reduced peroxidase activity triggered the accumulation of malondialdehyde in instar P. xylostella, especially after 10 min of treatment. The present findings provide experimental evidence and a theoretical basis for developing control strategies for P. xylostella under new HVEF environments.

Crop plants have coevolved phytohormone-mediated defenses to combat and/or repel their colonizers. The present study determined the effects of jasmonic acid (JA) accumulation during aphid infestation on the preference and performance of Sitobion miscanthi Takahashi (Hemiptera: Aphididae), and its potential role in fine-tuning hormone-dependent responses in XN979 wheat cultivar seedlings was evaluated via the transcriptional profiles of marker genes related to JA- and salicylic acid (SA)-dependent responses. The preference experiment and the life table data reveal that direct foliage spraying of 2.5 mM methyl jasmonate (MeJA) exhibited weak negative or positive effects on the preferential selection and the population dynamics and oviposition parameters of S. miscanthi. The transcription level of phytohormone biosynthesis genes shows that foliage spraying of MeJA significantly upregulated the marker genes in the JA biosynthesis pathway while downregulating the SA pathway. In addition, either MeJA treatment or previous aphid infestation significantly induced upregulated transcription of the genes involved in the JA- and SA-dependent defense responses, and the transcription level of the tryptophan decarboxylase (TaTDC) gene, which facilitates the conversion of L-tryptophan to tryptamine, was rapidly upregulated after the treatments as well. The main products of tryptamine conversion could play a crucial role in suppressing SA-dependent defense responses. These results will provide more experimental evidence to enable understanding of the antagonistic interaction between hormone signaling processes in cereals under aphid infestation.