IDENTIFICATION AND SCREENING OF CITRUS VEIN PHLOEM DEGENERATION (CVPD) ON BRASTAGI CITRUS VARIETY BRASTEPU (CITRUS NOBILIS BRASTEPU) IN NORTH SUMATERA INDONESIA

Identification and screening of Citrus Vein Phloem Degeneration (CVPD) on Brastagi citrus variety Brastepu
(Citrus nobilis Brastepu) in North Sumatra Indonesia is explained. The aim of the study is to explore the technique to obtain healthy Brastepu citrus to be used as a source of explants for in vitro propagation as a step in the preservation of threatened local citrus. The studies were conducted through collection of survived Brastepu citrus followed by screening the CVPD in the plants. Various procedures in the field and in the laboratory have been conducted to screen infected CVPD in Brastepu citrus. Visual examination from leaf, fruit, and seed appearance becomes preliminary information for CVPD infection in the citrus plant. Iodine test was used to
support results obtained by visual observation. Histochemical test and the PCR analysis have confirmed that 12 samples of Brastepu citrus are free from CVPD and eight citrus are infected by CVPD. Adequate informations
have been obtained to confirm healthy citrus tree which are then to be used as sources of explants for in vitro
propagation in the preservation of Citrus nobilis Brastepu.