Variasi Haplotipe Gen Cytochrome c Oxidase 1 dan 2 (COI dan COII) DNA Mitokondria pada Penggerek Batang Padi Kuning Scirpophaga incertulas (Walker) (Lepidoptera: Crambidae).

Abstract

Penggerek batang padi kuning, Scirpophaga incertulas merupakan salah satu serangga utama yang menyerang tanaman padi di Indonesia. Kerusakan tanaman padi disebabkan oleh aktivitas larva S. incertulas di dalam batang padi. Dua gejala kerusakan tanaman padi yang disebabkan oleh larva S. incertulas yaitu gejala sundep pada fase vegetatif dan gejala beluk pada fase generatif. Gejala sundep disebabkan oleh titik tumbuh tanaman padi yang mati pada fase vegetatif. Sedangkan, gejala beluk disebabkan oleh pangkal malai tanaman padi yang dikerat oleh larva serangga ini. Aktivitas larva S. incertulas pada fase generatif tersebut menyebabkan pangkal malai menjadi mati sehingga bulir padi menjadi hampa.

Scirpophaga incertulas or yellow rice stem borer (Lepidoptera: Crambidae) is one of the main insects caused damage yields in rice in Asia, including Indonesia. In the first instar of S. incertulas larva, the moth cannot be discriminated with other species of rice stem borers. Hence, a molecular approach is needed for early detection purpose. Previous study found six haplotypes of cytochrome oxidase 1 (COI) of S. incertulas from Java and four haplotypes of cytochrome oxidase 2 COII gene in S. incertulas from West Java. The objective of this research was to explore further the haplotype variations of the S. incertulas of COI and COII genes in Central Java, Special Region of Yogyakarta (DIY), East Java, and Bali, to fulfill the haplotypes variation data in Indonesia. The study found three new haplotypes (haplotype 7, 8, and 9) of S. incertulas COI sequences as well as three new haplotypes (haplotype 5, 6, and 7) of COII sequences. Those new haplotypes of S. incertulas COI gene were found in Lumajang, Sleman, and Pemalang regions. DNA alignment analyzes result based on S. incertulas COII gene revealed three new haplotypes i.e. haplotype 5 in Mojokerto, Tabanan, Lumajang, Pemalang, Klaten, Jember, and Kebumen region, haplotype 6 in Probolinggo regions, and haplotype 7 in Situbondo region. Nucleotide variations of moth S. incertulas COII were higher compare to COI gene. Database of COI and COII haplotype variations of yellow rice stem borer can be used as markers to differentiate S. incertulas with other species of rice stem borers during the first larva instar for their early detection. Phylogenetic analysis of S. incertulas COII revealed three clusters in Java and Bali.