English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Ultraviolet-A (UV-A) is the main component of UV radiation in nature. However, its role on plant growth, to a large extent, remains unknown. In this study, tomato ( Solanum lycopersicum  ‘Beijing Cherry Tomato’) seedlings were cultivated in an controlled environment in which UV-A radiation was provided by UV-A fluorescent lamps (λ max  = 369 nm) with a fluence rate of 2.28 W·m −2 . The photoperiod of UV-A radiation was 0, 4, 8, and 16 hours, which corresponds to control, UV-A4, UV-A8, and UV-A16 treatments, respectively. The photosynthetic photon flux density ( PPFD ) was 220 μmol·m −2 ·s −1 , which was provided by light-emitting diodes (LEDs) with a blue/red light ratio of 1:9, the photoperiod of  PPFD  was 16 hours. We showed that supplementing 8 and 16 hours of UV-A to visible radiation (400–700 nm) stimulated plant biomass production by 29% and 33%, respectively, compared with that of control. This resulted mainly from larger leaves (i.e., 22% and 31% in 8 and 16 hours UV-A, respectively), which facilitated light capture. Supplemental UV-A also enhanced photosynthetic capacity, as indicated by greater net photosynthesis rates in response to CO 2  under saturating  PPFD . Furthermore, the greatest stomatal conductance ( g  S ) value was observed in UV-A16, followed by UV-A8, which correlated with the greater stomatal density in the corresponding treatments. Moreover, supplemental UV-A did not induce any stress, as the maximum quantum efficiency of photosynthetic system II (PSII) ( F  v / F  m ) remained ≈0.82 in all treatments. Similarly, chlorophyll content and leaf mass area (LMA) were also unaffected by UV-A radiation. Taken together, we conclude that supplementing reasonable levels of UV-A to visible radiation stimulates growth of indoor cultivated tomato seedlings.

Ultraviolet-A Radiation Stimulates Growth of Indoor Cultivated Tomato (Solanum lycopersicum) Seedlings