Shortcut to long-distance developing of a tissue culture medium: micropropagation of mature almond cultivars as a case study

Abstract

: Culture medium development methods are time-consuming, laborious, and require a large amount of experimental materials. The Nas hypothesis for the development of a micropropagation medium offers a less time-consuming and a less laborious approach. According to this hypothesis, the composition of a culture medium for a particular species should resemble the seed composition. In accordance with this hypothesis, first, an almond culture medium [Nas Almond Medium (NAM)] was developed based on almond kernel composition. Then, using mature tissues of almond cultivars, the growth of cultures on NAM was compared to that on Murashige and Skoog medium (MS), Woody Plant Medium (WPM), Driver and Kuniyuki medium (DKW), and Nas and Read medium (NRM). Medium composition had profound effects on the 3 growth parameters of number of shoots per explant, mean shoot length, and the productivity. With respect to mean number of shoots and mean shoot length, NAM was the best medium. NAM was also the most productive medium. NAM was up to 35%, 49%, 68%, and 69% more productive than NRM, MS, DKW, and WPM, respectively. The results suggest that formulating the composition of a culture medium based on the seed content can be a straightforward universal method of medium development for micropropagation.