Research Progress and Prospects of Flowering Induction for Seagrass Sexual Reproduction

Seagrass is a group of flowering plants capable of completing their life cycle in a marine environment. It not only provides a refuge for biodiversity and essential fish spawning and nursery grounds, but also provides ecologically and socioeconomically important services for urban coasts. Seagrass is widely distributed along temperate and tropical coastlines globally. The biodiversity corresponds with differences in the relative importance of sexual (seed production) and asexual (clonal growth) life history strategies in the maintenance of seagrass populations. Sexual reproduction in predominantly clonal marine plants increases recombination favoring adaptation and enhancing species resilience to environmental change. Flowering induction is an important link in the transition from vegetative growth to reproductive growth of seagrasses. Recent studies on seagrasses suggest that flowering intensity and frequency are correlated with global climate change, and the response of seagrasses will be more complex, and potentially more resilient than previously imagined.Seagrass environments are characterized by physical conditions, such as temperature, salinity, currents, waves, turbulence, and light. Each of these parameters has the potential to affect vegetation from the smallest (molecular and physiological) to the largest (ecosystem as well as global) scale. Based on bibliometric methods, this study summarized the development trend of seagrass flowering formation research. The SCIE database of the Web of Science core collection of the Institute for Scientific Information (ISI) was chosen as the retrieval source, and select published international journals were chosen as the research object. With "seagrass flowering" as the search keyword, a total of 300 related publications were retrieved. In terms of the number of relevant publications each year, there was an overall increasing trend, indicating that this topic has gradually received more attention in recent years, which has great research potential.This review summarizes the research progress of flowering inducement in the sexual reproduction of seagrasses and discusses the influence of physical factors on the flowering induction of seagrasses. It was previously thought that the flowering pathway initiated by seagrasses in response to environmental factors and endogenous signals may focus on the photoperiod, vernalization, and spontaneous pathways. However, the sexual reproduction of different species is different, and studying the interaction between seagrasses and their physical environment may improve understanding of the processes that influence their biology. This review focuses on the following aspects: 1) Clarifying the period of concentrated flowering of the seagrass bed, which is conducive to studying the inducement of flowering of seagrass and protecting the seagrass seed bank. 2) Discussing whether more genotypes of seagrass should be introduced for planting in the process of seagrass bed repair to avoid large-scale clonal reproduction of a single genotype of seagrass. 3) How sexual reproduction of seagrasses under adverse environments can be used to indicate changes in the climate and environment. However, existing studies have paid little attention to the sexual reproduction of seagrass beds, and do not consider the sexual reproduction rate as a long-term monitoring indicator. It is suggested that the sexual reproduction rate should be combined with environmental factors in the future long-term monitoring and assessment of the health status of seagrass beds to jointly assess their pressure status.