In vitro propagation method for production of morphologically and genetically stable plants of different strawberry cultivars

Abstract Background As strawberries are susceptible to somaclonal variation when propagated by tissue culture techniques, it is challenging to obtain the true-to-type plants necessary for continuous production of fruits of stable quality. Therefore, we aimed to develop an in vitro propagation method for the production of true-to-type plants of five different strawberry cultivars from meristems cultured in media containing different concentrations of kinetin (Kn). Results For all the cultivars, shoot induction was successful only in the meristems cultured in the medium without Kn and the medium containing 0.5 mg L−1 Kn. The shoots obtained from explants cultured in media supplemented with 0.5 mg L−1 Kn exhibited better plant growth parameters than those cultured in media without Kn and were genetically stable when compared with conventionally propagated plants for all the cultivars. Vegetative and sexual characters and fruit quality attributes observed in the plants derived from meristems cultured on 0.5 mg L−1 Kn and the conventionally propagated plants were not significantly different when grown for three continuous growing seasons under greenhouse conditions. Conclusion The culture of meristems in the medium containing 0.5 mg L−1 Kn is suitable for the efficient propagation of true-to-type plants of different strawberry cultivars and continuous production of fruits with stable quality. Hence, we expect that the method presented in this study will be helpful for the commercial production of true-to-type plants generated in vitro for other strawberry cultivars

Electrospinning of chitin nanofibers: Degradation behavior and cellular response to normal human keratinocytes and fibroblasts

An electrospinning method was used to fabricate chitin nanofibrous matrices for biodegradability and cell behavior tests. The morphology of as-spun chitin nanofibers (Chi-N) and commercial chitin microfibers (Beschitin W®; Chi-M) was investigated by scanning electron microscopy. From the image analysis, the average diameters of Chi-N and Chi-M were 163 nm and 8.77 μm, respectively. During in vitro degradation for 15 days, the degradation rate of Chi-N was faster than that of Chi-M, likely due to higher surface area of Chi-N. Chi-N that was grafted into rat subcutaneous tissue had almost degraded within 28 days, and no inflammation could be seen on the nanofiber surfaces or in the surrounding tissues (except in the early stage wound). To assay and compare the cytocompatibility and cell behavior with Chi-N and Chi-M, cell attachment and spreading of normal human keratinocytes and fibroblasts seeded on chitin matrices and the interaction between cells and chitin fibers were studied. Relatively high cell attachment and spreading of all the cells tested were observed on Chi-N in comparison to Chi-M, and Chi-N treated with type I collagen significantly promoted the cellular response. Our results indicate that the Chi-N, alone or with extracellular matrix proteins (particularly type I collagen), could be potential candidates for the cell attachment and spreading of normal human keratinocytes and fibroblasts. This property of Chi-N might be particularly useful for wound healing and regeneration of oral mucosa and skin