Background Early flowering and maturing flax ( Linum usitatissimum L . ) cultivars are better adapted than lines with a longer reproductive phase for the short growing season of the northern Canadian Prairies. We examined the role of long days (LD) and short days (SD) on the time taken to flower in five established flax cultivars and three mutant-derived F 10 lines. The photoperiod sensitivity of these eight different genotypes was determined using a reciprocal transfer experiment involving weekly transfers between LD and SD environments. Results The genotypes tested had varying degrees of photoperiod sensitivity and demonstrated reduced time to flowering if exposed to LD environments prior to a critical time point. The duration of each of the three phases of vegetative growth differed among the genotypes studied. Transfers from SD to LD shortened the vegetative stage, reduced time to flowering, and extended the reproductive phase in the genotypes studied. Mutant-derived lines RE1/2/3 flowered significantly earlier compared to CDC Sorrel, CDC Bethune, Flanders, Prairie Thunder, and Royal. Modelling of the flowering times indicated that transferring the cultivars from SD to LD increased the photoperiod sensitive time; however, different reproductive phases for mutant lines were not defined as parsimonious models were not identified. Expression of the putative flax homologs for CONSTANS ( CO ), FLOWERING LOCUS T ( FT ), and GIGANTEA ( GI ) was examined in the leaves of Royal and RE1/2/3 plants at 10, 15, 19 and 29 days after planting. Expression of putative FT homologs was detected in all three early-flowering lines but expression was negligible, or not detected, in Royal. Conclusions Models defining the three phases of reproductive development were established for the five cultivars studied; however, it was not possible to identify these phases for the three early flowering and photoperiod insensitive epimutant-derived lines. A putative flax homolog of FT , a key regulator of flowering time, is more highly expressed in RE plants, which may condition the day-length insensitivity in the early flowering ‘epimutant’ lines. Electronic supplementary material The online version of this article (10.1186/s12870-019-1763-5) contains supplementary material, which is available to authorized users.

Background: The hypertrophy and conversion of postnatal muscle bers largely determine the yield and quality of pork, and the growth and development of muscle bers involve complex molecular regulation. miRNA is a kind of endogenous noncoding RNA fragments and widely involved in the proliferation and differentiation of livestock and poultry myoblasts.Results: In this paper, the longissimus dorsi muscle tissues of Lantang pigs at 1 and 90 days of age (LT1D and LT90D) were collected and pro led by miRNA-seq. The longissimus dorsi muscle of LT1D and LT90D expressed 1871 and 1729 miRNA candidates respectively, and 794 miRNAs were shared. We identi ed 16 differentially expressed miRNAs between LT1D and LT90D and explored the function of miR-493-5p in muscle development. The miR-493-5p inhibited the proliferation and promoted the differentiation of myoblast cells. GO and KEGG pathway analysis of 164 target genes of miR-493-5p, we found ATP2A2, PPP3CA, KLF15, MED28 and ANKRD17 genes related to muscle development. RT-qPCR detection showed that the expression level of ANKRD17 was highly expressed in LT1D libraries, and the double luciferase report test preliminarily proved that miR-493-5p and ANKRD17 have a directly targeting relationship.Conclusions: In this study, we revealed the roles of miR-493-5p in development of muscle bers and identi ed the relationship network of miR-493-5p and ANKRD17, providing data support for pig breeding.

No abstract