MICROGRAFTING OF SELECTED KENYAN PAPAYA (CARICA PAPAYA L.) LINES

Abstract

Grafting facilitates the exploitation of attributes of two varieties; the scion being responsible for the good quality characteristics of the product and the rootstock providing desirable attributes like tolerance to challenges associated with the medium of anchorage. The aim of this study was to evaluate success of in vitro micrografting method in three selected Kenyan papaya lines. In the study, shoot tips; c. 1.0cm were excised from three month old seedlings, sterilised and cultured on Murashige and Skoog basal media supplemented with 0.1mg/l 6-Benzylaminopurine and 0.05mg/l α Naphthalene Acetic Acid. When the shoots reached a length of c. 2.0 cm, the upper 1.0 cm tips were excised and used as scions, while the remaining portion was used as rootstock. The scions and rootstocks of the same genotype were used as the controls. Twenty eight days after grafting, the proportion of scions that were still alive, number of leaves and scion length of individual combinations were recorded. From all grafting combinations tested, the highest success rate was obtained from papaya line1 and papaya line 2 grafted on their own rootstocks papaya combinations with 75%and 80% grafting success rates respectively. Papaya lines grafted on their own rootstocks gave better results than when grafted on different rootstocks.