Resource allocation, as well as the tradeoffs among different reproductive components, plays an important role in the adaptability of plants to different environments. The hybrid may exhibit a higher adaptability in life history in heterogeneous environments because of the genetic variation derived from its parents. In this study, we exploited three levels of water depths and two types of sediments to investigate the resource allocation pattern of the first generation of the natural hybrid Potamogeton Âintortifolius compared to its parents P. wrightii and P. perfoliatus. We also measured the ramet survivorship and the seed set of the hybrid P. Âintortifolius. Our results showed that P. Âintortifolius had higher ramet survival than its parents at 1.5-m water depth on clay sediment. The possible tradeoffs showed that in P. Âintortifolius the tradeoff pattern between sexual and clonal reproduction was more pronounced in limiting environments. The individuals allocated more resources to sexual reproduction when the environment was limiting, which might confer a higher ability to utilize resources, to produce offspring and to found new populations. Although the seed set of P. Âintortifolius was lower than its parents, it had a higher ability to increase its seed set when the environment was limiting (sandy sediment) than its parents, which might benefit its future survival. These results indicated that the F 1 hybrid P. Âintortifolius was more able to adapt to limiting environments than one or both of its two parental taxa.

The Centropristis striata is an important economically marine fish and facing a serious threat from various pathogens. Edwardsiella piscicida is one of the fish pathogens that seriously infect cultured and wild fish species. To understand the molecular immune mechanisms underlying the response to E. piscicida, a comparative gene transcription analysis was performed through RNA‐Seq technology. The low‐quality sequences were excluded, and the high‐quality sequences were assembled into a total of 60,759 contigs with an average length of 988.95 bp. A gene ontology (GO) analysis was employed to classify 5744 genes according to three major functional categories: molecular function, cellular component and biological process. A total of 19,918 genes were successfully annotated into 26 functional categories according to the clusters of orthologous groups (COG) classification. Furthermore, 15,006 genes were classified into 332 KEGG pathways. The q‐value was introduced to estimate 5109 genes significantly differentially expressed which includes 1781 up‐regulated genes and 3328 down‐regulated genes. The differentially expressed genes were involved in the major immune‐related pathways which refer to the pathogen recognition, inflammation, Toll‐like receptor and chemokine signalling pathways. Moreover, 24,487 potential simple sequence repeats (SSRs) and 193,760 candidate single nucleotide polymorphisms (SNPs) were detected and identified in the C. striata liver transcriptome. This work not only provides a valuable resource for further understanding of the antibacterial molecular mechanism of C. striata but also contributes to facilitate future studies on gene expression and functional genomics.