Document Type : Research Paper


1 Researcher, Department of Horticulture, Seed and Plant Improvement Institute, Karaj, Iran

2 Assistant Professor, Agricultural and Natural Resources Research Center, Shahrekord, Iran


According to problems caused by application of non-uniform seedling rootstocks in stone fruit trees
orchards, the use of uniform and consistent rootstocks with these trees is essential. For determination of
the best culture medium, explants of apical and lateral buds of Tetra, Nemaguard and GF677 rootstocks
were prepared. Explants were placed in modified MS, WPM and Knop media each containing 0.6 mg/l
BAP and 0.01mg/l NAA in mid-Spring and after disinfection. This research was carried out as factorial
experiment in a completely randomized design with four replicates and four observations per each
replication. Tetra, GF677 and Nemaguard rootstocks produced the highest of plantlet number
respectively. Nemaguard rootstock did not show any proliferation in Knop medium and Nemaguard
explants showed chlorosis on this medium. This medium caused chlorosis in produced plantlets of Tetra
explants. Explants of every three rootstocks were produced the highest plantlet number and length in MS
modified medium. Therefore, combinations of plant growth regulators were evaluated in this medium.
Three different combinations were evaluated. Among different combinations of plant growth regulators
(0.8 and 1 mg/l BAP and 0.1 and 0.5 mg/l NAA), the highest plantlet number and length were produced
in MS medium containing 0.6mg/l BAP and 0.01mg/l NAA. Increase of plant growth regulators
concentrations led to vitrification and callus production in GF677 rootstock. The highest root number and
rooting percent were achieved in modified MS medium containing 1 mg/l NAA and explants of Tetra
rootstock produced the highest root number and length.