Species Identification of Meloidogyne on Carrot in Cianjur, West Java

Abstract

Root knot nematodes (RKN), Meloidogyne spp., has been reported as the cause of carrot branched tuber on several vegetable production centers in Central and East Java. The disease caused the reduction of the quantity and quality of the tubers and lead to significant yield losses. This research aimed to identify species of Meloidogyne that associate with carrot branched tuber diseases and determined relationship of RKN species in Cianjur, West Java with Meloidogyne species in Genbank. Samples were collected from Agropolitan Cianjur, West Java then identified at Laboratory of Plant Nematology and Plant Virology, Faculty of Agriculture, Bogor Agriculture University. RKN identification was done by observing morphological characters of female nematode and by DNA amplification using specific primers. DNA was extracted from female nematodes and amplified through PCR using species specific primers (Fjav/ Rjav for M. javanica, Far/ Rar for M. arenaria and Finc/ Rinc for M. incognita) and multiplex primer (M. hapla, M. chitwoodi and M. fallax). Nucleotides of PCR results were sequenced without cloning process. Field observation showed that there were three types of tuber symptoms caused by RKN infection, that were branched tubers, short bulb and break tubers. In addition, location of galls on root of carrot also divided into three types, i.e. attached on tuber surface, enlarged bulb gall and hairy roots. Based on perineal pattern, four Meloidogyne spesies were identified namely M. arenaria, M. hapla, M. incognita, and M. javanica. Phylogenetic analysis showed that M. javanica from Cianjur, West Java related closely to China isolate with the homology level of 91.9%. Whereas M. hapla from Cianjur, West Java had nucleotide sequence which was relatively not different from isolates of other countries.