Fatty acids are not only widely known as energy sources, but also play important roles in many metabolic pathways. The significance of fatty acids in modulating the reproductive potential of livestock has received greater recognition in recent years. Functional fatty acids and their metabolites improve follicular development, oocyte maturation and embryo development, as well as endometrial receptivity and placental vascular development, through enhancing energy supply and precursors for the synthesis of their productive hormones, such as steroid hormones and prostaglandins. However, many studies are focused on the impacts of individual functional fatty acids in the reproductive cycle, lacking studies involved in deeper mechanisms and optimal fatty acid requirements for specific physiological stages. Therefore, an overall consideration of the combination and synergy of functional fatty acids and the establishment of optimal fatty acid requirement for specific stages is needed to improve reproductive potential in livestock.

Cultivar renewal (CR) contributes greatly to rice yield increase in China and even in the world. However, few studies were focused on the impact and mechanism of CR on field methane (CH₄) emissions. A 2-year field experiment was conducted using 14 typical japonica rice cultivars released in the Yangtze River Basin of China during the last 70 years. The grain yield, root morphophysiological traits and their relationships with CH₄ emissions were examined. The results showed that the grain yields of cultivars in the 1960–2010s increased by 18.8–93.9% while the CH₄ emissions decreased by 9.5–41.2% compared with the 1950’s cultivars. The daily and cumulative CH₄ emissions during the panicle differentiation stage (PD) were reduced significantly, which contributed greatly to the CH₄ mitigation of the whole growing season. The CR notably increased root biomass, root/shoot ratio, root oxidation activity, and the total organic carbon in root exudates (ETOC), and decreased the ratios of ETOC/yield, ETOC/root biomass and ETOC/shoot biomass. Nitrogen fertilizer applied during panicle differentiation could improve the root physiology and decrease the ETOC/yield and ETOC/root, therefore reducing CH₄ emissions. Our findings illustrated that CR reduced CH₄ emissions by improving root traits and by optimizing the photosynthate allocation to biomass and grain yields. Applying nitrogen fertilizer during panicle differentiation could further mitigate the CH₄ emissions in paddies.

Rice root aerenchyma (RA) and irrigation practices play critical roles in key physiological processes in rice paddies, influencing both grain yield and methane (CH₄) emissions. However, the interaction between RA and irrigation practices, as well as its implications for CH₄ mitigation, remains poorly understood, complicating efforts to identify rice cultivars suited for reducing CH₄ emissions. To address this, we conducted field and pot experiments to investigate how RA impacts rice yield and CH₄ emissions under two common irrigation methods: continuous flooding (CF) and alternate wetting and drying (AWD). Our findings reveal that the interaction between RA and irrigation regime significantly affects both yield and CH₄ emissions. Under CF, cultivars with enhanced RA formation exhibited higher yields and lower CH₄ emissions, likely due to increased root oxygen loss, which promotes CH₄ oxidation and enhances nitrogen availability for plant growth. In contrast, under AWD, no significant differences in yield, methanogenesis, or methanotrophy were observed among cultivars with varying RA development. However, cultivars with well-developed RA increased CH₄ emissions by 28%–32% compared to those with less-developed RA, likely due to enhanced CH₄ transport from anaerobic soil layers to the atmosphere. Consistent with these observations, inhibiting RA development through root irrigation with brassinosteroids reduced CH₄ emissions under AWD conditions. In summary, our study demonstrates that AWD can reverse the effects of RA on CH₄ emissions, emphasizing the importance of integrating irrigation practices into CH₄ mitigation strategies and accounting for cultivar-specific variations.