Maize Rotation Combined with Streptomyces rochei D74 to Eliminate Orobanche cumana Seed Bank in the Farmland

Abstract

Orobanche cumama wallr. is the sunflower root parasitic weed with special life stage in which seed germination and parasitism take place in the soil. In practice, applying microbial agents and trapping crop rotation are utilized separately, or just one of them is selected to control O. cumana. The development of the sunflower industry is severely constrained on the farmland, where there is high density of O. cumana’s seed banks. In this study, two biological control methods were combined to solve the problem of O. cumana parasitism. The bioassay experiment showed that the high concentration fermentation filtrates of Streptomyces rochei D74 could effectively inhibit the germination and growth of the germ tube of O. cumana seeds. As the concentration was increased to 3.1 mg/mL, O. cumana was almost unable to sprout. A two-year pot experiment revealed that the use of D74 agents and sunflower–maize–sunflower rotation together promoted sunflower growth, as shown by the biomass accumulation, plant height, and denser root systems. The combined method resulted in a significant decrease in the number of O. cumana parasitism, compared to one method alone. Additionally, it affected the bacterial community composition of sunflower rhizosphere, mostly leading to an increase in Streptomyces and Brevibacterium and a decrease in Arthrobacter. This experiment, combined with multiple biological control, means significantly reducing the parasitism of O. cumana, which provides an effective foundation for practical application.

OsDWARF10, transcriptionally repressed by OsSPL3, regulates the nutritional metabolism of polished rice

“…The expression of OsD10 was significantly reduced in the leaves of OsSPL3.OEs leaves than in ZH11 ( Figure 5G ), providing further evidence that OsSPL3 effectively inhibits OsD10 transcription in vivo . Seed germination in Orobanche is stimulated by SL, and the germination rate serves as an indicator of SL levels ( Cardoso et al., 2014 ; Xi et al., 2022 ). Thus, to investigate whether OsSPL3 affects SL content, we performed an Orobanche germination bioassay.…”

Comparative analysis of two neighboring conducive and suppressive soils towards plant parasitism caused by Phelipanche ramosa L. Pomel on Brassica napus L.

“…This gram-positive lamentous group of bacteria are ubiquitous in the rhizosphere and are considered as PGPRs and antagonists of many pathogens, mainly due to their ability to secrete numerous bioactive compounds and plant hormones [104][105][106]. In addition, Streptomyces species have been shown to suppress germination, radicle elongation and late development of Phelipanche aegyptiaca for S. pactum [80] or O. cumana for S. enissocaesilis [79] and S. rochei D74 [107].…”

Silicon Fertilization Improves Sunflower Rhizosphere Microbial Community Structure and Reduces Parasitism by Orobanche cumana Wallr.

“…As an obligate holoparasite, O. cumana has fully lost the ability to photosynthesize. Herbicide strategies such as imidacloprid in combination with herbicide-resistant sunflower [9,10], crop rotation including non-host bait crops that induce O. cumana seed germination [11] and resistant varieties are commonly used for parasitic weed management [12]. However, these methods have some limitations and can easily increase the financial burden on farmers.…”