Sexual and asexual propagation of Natal Plum (Carissa Macrocarpa L.)

Abstract

This research aimed to study the effect of some physical (water soaking, cold stratification) and chemical (potassium nitrate, gibberellic acid) treatments on the germination of Natal Plum seeds, in addition to the effect of the auxin type (IBA, IAA) and its concentration
 (0, 2000, 3000, 4000 ppm) on the rooting of semi-woody cuttings and the quality of the resulting plants. The research was carried out in the nursery and laboratories of the Faculty of Agriculture, Latakia University, for two agricultural seasons (2024 and 2025). The results of sexual propagation showed that the cold stratification treatment for 20 days was superior to the other treatments in germination percentage, which reached
 91.33%, followed by the potassium nitrate treatment (2%), with a germination percentage of 63.33% compared to 26.67% in the control. Soaking treatments with either potassium nitrate (2%) or gibberellic acid (100 and 200 ppm) also achieved the best quality of the resulting seedlings.

Vegetative propagation results indicated that the cuttings treated with both types of auxin and at all concentrations used were superior to the control in rooting percentage. The auxin IBA was also superior to IAA in rooting percentage (31.96, 13.03%), in the average number of roots formed per cutting (9.36, 6.56) and in the average root length
 (6.59, 5.14 cm), respectively, according to the general average. The results also showed the positive effect of treating cutting with auxin, especially IBA, on the vegetative growth indicators of the resulting plants (shots number, leaves number and leaf surface area, percentage of dry matter and the total chlorophyll content in leaves) and in all rooting indicators when used at a concentration of 4000 ppm.