Use of starch-gelled medium for tissue culture of some fruit crops

Six cultivars of apple and two of red raspberry consistently produced equal or significantly better shoot proliferation on modified Murashige and Skoog medium gelled with a mixture of corn starch and Gelrite than on the same medium gelled with agar. Two pear cultivars grown on starch-Gelrite medium produced hyperhydric shoots and almost no growth, but the addition of a polysaccharide hydric control (antivitrifying) agent to the medium eliminated hyperhydricity. The resulting shoot proliferation equaled or exceeded that on the agar-gelled medium. The starch-Gelrite mixture is easy to prepare and gelling agent costs are only 10–15% of agar, or less if starch is purchased in bulk. Although the opaque gray-white medium makes it more difficult to detect internal contaminants, external contaminants are easily discerned.The US Government's right to retain a non-exclusive royalty-free license on and to any copyright is acknowledged.