Daya hidup planlet karet asal in vitro microcutting pada berbagai periode penutupan sungkup plastik dan komposisi media tumbuh Survival rate of in vitro microcutting-derived rubber plantlets on various plastic cover closed periods and medium compositions

Abstract

In vitro culture through microcutting technology can be used for clonal propagation of rubber (Hevea brasiliensis Muell. Arg.) rootstocks. Acclimatization of in vitro plantlets to ex vitro conditions is a major bottleneck in the micropropagation of many plants.This research was conducted to study the effect of plastic cover closed period and media composition on the survival rate of rubber plantlets. Plantlets derived from microcutting were planted on plastic pots containing a mixture of soil, cocopeat, dung manure, and sand or zeolite. The plantlets were then placed inside a closed transparent plastic cover that opened after 2, 3, 4 and 6 weeks. The cover was placed under tree canopy. The second experiment used the same media composition with or without cocopeat and with sand or zeolite. At 1.5 month after culture, observation was done on the number of survived plantlets, plantlet height and the percentage of rooted plantlets. The results show that the best coverclosed period was six weeks and the best growing medium was a mixture of soil, cocopeat, dung manure, and zeolite (6:2:1:1v/v). On the two combined treatments, the survival rate was 73.3% after 1.5 month of acclimatization. The use of zeolite and a higher soil percentage gave positive influences on rubber plantlet survival rate. The second experiment results confirmed that the use of zeolite was better than sand and the use of cocopeat was definitely needed. It can be concluded that the best of acclimatization of rubber plantlets from microcutting was on a medium mixture of soil, cocopeat, dung manure, and zeolite (6:2:1:1) and placed inside a closed plastic cover for six weeks before the cover was opened gradually.