In Vitro Preservation of Autochthonous Plum Genotypes

Abstract

The paper presents results of the application of ‘Cold storage’ (CS), an in vitro technique for preservation of cultures at +5oC in total darkness. This simple in vitro preservation method is effectively employed in large plant gene bank repositories for the purpose of preservation of valuable plant germplasm. In order to protect from extinction autochthonous plums Crvena Ranka (Prunus insititia L.), Sitnica (Prunus domestica L.) and Cherry plum (Prunus cerasifera Ehrh.) a protocol for their in vitro preservation has been developed. Upon the establishment of aseptic culture, the studied genotypes were propagated in vitro on Murashige and Skoog (1962) medium of different hormonal composition, depending on genotype. During CS, in vitro shoots were maintained at +5oC in cold chamber for 3, 6 and 9 months in total darkness. Seven days after respective period, viability of shoots for further propagation was determined as well as multiplication parameters and length of axial and lateral shoots. Three months after maintaining shoots in CS, shoots of Crvena Ranka and Sitnica showed high shoot viability (in excess of 50%), while in Cherry plum viable shoots were etiolated showing symptoms of leaf necrosis (in more than 20%). However, after 6-month preservation under cold conditions, only shoots of Crvena Ranka survived showing necrosis on shoot tips, but they had viable, chlorotic lateral shoots (in excess of 45% of shoots). All three genotypes showed severe signs of necrosis after 9 months of cold storage.