In vitro screening procedure for osmotic tolerance in Prunus

Abstract

Significant growth differences (p≤<0.01) were observed for two micropropagated Prunus accessions after 14 days in culture when 685 mM mannitol was included in Quoirin and Lepoivre nutrient medium. While there was an 11% growth increase in fresh weight during the 28-day culture period for accession K537-067, explants from New Jersey Plumcot No. 3 increased fresh weight an average of 123%. Similar tests were conducted to determine the repeatability of this short term in vitro screening procedure. Explants of Mananna 2624 were subjected to two levels of mannitol, 275 mM and 550 mM, included in the Quoirin and Lepoivre nutrient medium. Three successive 28-day tests were conducted. Explants were examined at both 14 and 28 days after the onset of the experiment for net growth changes. Addition of mannitol to the nutrient medium at concentrations of 275 mM and 550 mM decreased explant fresh weights of Marianna 2624 to 36% and 28% of controls, respectively, at 28 days past initial culture. Initial fresh weight and fresh weight changes at day 14 were significantly different (p ≤ 0.05) between tests. No significant differences existed between tests with regard to weight changes at 28 days past initial culture. This information may aid Prunus breeders in the choice of procedures for inducing drought stress and screening large numbers of plant accessions.