Effect of the Sidewards Lighting on the Growth and Morphology of Potato Plantlets in vitro.

Abstract

Growth and morphology of potato (Solanum tuberosum L. cv. Benimaru) plantlets in the vessels in the sidewards lighting were compared with those in the vessels in conventional downwards lighting with and without addition of sugar to the medium. The amount of electricity for lighting per plantlet in the sidewards lighting was set to be the same as that in the downwards lighting.When sugar was added to the medium, dry weight, fresh weight, leaf area, and the maximum diameter of stem of the plantlets on day 28 in the sidewards lighting were 1. 4, 1. 9, 1.8, and 1. 1 times greater than those in the downwards lighting, respectively. When sugar was not added to the medium, these values were 1. 7, 1. 9, 1. 7, and 1. 2, respectively. On the other hand, shoot length of the plantlets in the sidewards lighting was 60% of that of the plantlets in the downwards lighting regardless of sugar treatments.The sidewards lighting promoted the growth of potato plantlets, therefore, the sidewards lighting could reduce the relative consumption of electricity for lighting by shortening the culture period and produce the plantlets with reduced stems.