IN-VITRO ROOTING OF ROOTSTOCK GF-677 (PRUNUS-AMYGDALUS X P-PERSICA) AS INFLUENCED BY MINERAL CONCENTRATION OF THE NUTRIENT MEDIUM AND TYPE OF CULTURE-TUBE SEALING MATERIAL

Rooting of the rootstock GF-677 (Prunus amygdalus x P. persica) in vit ro was significantly affected by the mineral concentration of the nutr ient medium and by the type of tube sealing material (rubber and paraf ilm). The results showed that increasing the mineral concentration of the WPM from half (0.5x) to twice the normal (2x) resulted in a signif icant increase of percent rooting, number, mean length and fresh weigh t of roots. However, when the MS substrate was employed, number and me an length of roots were greater at 1x and 0.5x mineral concentration, respectively. In both media fresh weight of roots was increased by inc reasing the mineral concentration and the MS medium responded better t han WPM at the low mineral concentration. Rubber capping proved superi or to parafilm with respect to rooting percentage, number and root fre sh weight. Mean root length, however, declined with rubber as capping material.