Abstract
The effect of purple nonsulfur bacteria (Rhodobacter sphaeroides) application on the growth and quality of Komatsuna (Brassica campestris) was investigated under different light qualities using blue (470 nm) and red (660 nm) light emitting diodes (LED) . Freeze dried purple nonsulfur bacteria (PTBP) were used for the investigation. Komatsuna plants were grown for 21 days with or without PTBP application under 3 different light qualities (blue-100%, red-100%, blue 20%-red 80%) at 20°C in a growth chamber. The PTBP application significantly promoted root growth under the blue-100% treatment, whereas the no PTBP application under the same light quality reduced root growth compared to the other light quality treatments. Moreover, the PTBP application under blue-100% increased chlorophyll and carotenoid contents, and reduced total sugar and ascorbic acid contents. On the other hand, the PTBP application under red-100% reduced nitrate and ascorbic acid contents. These results indicate that PTBP application significantly promotes growth and quality of Komatsuna under blue light, and may also compensate for red light.
