Dampak iradiasi sinar Gamma Co-60 terhadap beberapa aspek genetika reproduksi nyamuk Aedes albopictus (SKUSE)

SUDARYADI, Ignatius, Prof.dr. Sugeng Juwono Mardihusodo, M.Sc

2006 | Tesis | S2 Ilmu Kedokteran Dasar dan Biomedis

Latar Belakang. Sebagai salah satu vektor potensial penyakit demam berdarah dengue (DBD) keberadaan Aedes albopictus di Indonesia menjadi hal serius untuk dikaji. Penggunaan insectisida yang terencana dalam jangka waktu yang lama untuk menekan kepadatan nyamuk Ae. aegypti ternyata menjadi salah satu penyebab meningkatnya kepadatan nyamuk Ae. albopictus yang berada pada daerah sebaran yang sama Sampai saat ini pencegahan penyakit DBD hanya tergantung pada pengendalian vektor penyakit. Strategi pengembangan untuk pengendalian hayati memiliki beragam metode, salah satunya adalah pengendalian secara genetik dengan menggunakan teknik jantan mandul. Tujuan. Tujuan dari penelitian ini yaitu : untuk menentukan dosis letal 50% iradiasi sinar Gamma Co-60; menentukan sterilitas, kapasitas kawin dan kapasitas reproduksi Ae. albopictus jantan iradiasi, dan menguji kompetisi kawin nyamuk jantan iradiasi dan jantan normal Cara Penelitian. Penelitian ini mencakup 3 percobaan. [1] Penentuan dosis letal 50% (LD50) iradiasi sinar gamma Co-60 dengan analisis probit. [2] Pengujian sterilitas nyamuk jantan, kapasitas kawin, dan kapasitas reproduksi dengan pengamatan pada status inseminasi nyamuk betina dan populasi hasil uji perkawinan. [3] Pengujian kompetisi kawin, dengan cara nyamuk jantan F1 iradiasi, nyamuk jantan normal, dan nyamuk betina normal bersama-sama dimasukkan dalam sangkar-sangkar perkawinan dengan rasio : 0:1:1; 1:0:1; 1:1:1; 5:1:1; 10:1:1; dan 20:1:1, pengamatan pada perkembangan populasi turunannya. Semua percobaan dikerjakan di laboratorium. Analisis statistik dilakukan untuk mengetahui ada tidaknya beda nyata (P<0,05) antar kelompok perlakuan. Hasil. Hasil percobaan menunjukkan bahwa LD50 iradiasi sinar gamma Co-60 sebesar 17,5 krad. Dosis ini menyebabkan nyamuk jantan Ae. albopictus menjadi semisteril, kapasitas kawinnya menurun 4%, dan kapasitas reproduksinya menurun 45,4 %. Pada generasi berikutnya, kapasitas kawin menurun 7,7% dan kapasitas reproduksi menurun 76,2 %. Uji kompetisi perkawinan dengan rasio 5:1:1 (jantan iradiasi : jantan normal : betina normal) mampu mereduksi populasi keturunnanya sebesar 54,6%, pada rasio 10:1:1 mereduksi 75,3%, dan pada rasio 20:1:1 mereduksi 81,4%. Simpulan. Iradiasi sinar gamma Co-60 dosis 17,5 krad menyebabkan nyamuk jantan Ae. albopictus semisteril, menurunnya kapasitas kawin dan kapasitas reproduksi, dan reduksi populasinya.

Background. The establishment of Aedes albopictus in Indonesia has become a serious problem to be studied as the one of potential DHF vector disease. The long term intensity of selection pressure on the vector insect Aedes aegypti could be one possible factor related to the increase of Aedes albopictus density in areas where their distributions overlap. Up to the present, the prevention of DHF only depends on the success of the vector control. The developing strategies of biological control has various methods one of the methods is genetic control by using the sterile male technique. Objectives. The objectives of this study were : to determine the lethal dose 50% of Gamma Co-60 irradiation; to determine the sterility; the mating capacity, the reproductive capacity of Ae. albopictus males irradiation; and to determine the mating competitiveness of males mosquitoes (irradiated and unirradiated). Methods. This study comprised 3 experiments. [1] The determination of lethal dose 50% (LD50) of Gamma Co-60 irradiation by using probit analysis [2] The determination of sterility, mating capacity, and reproductive capacity of Ae. albopictus males were done with observation on the insemination status of females and the population of their progeny after mated [3] In the mating competitiveness test the F1 males iradiated, the normal males, and the normal females were confined together in the cages at the ratio of 0:1:1; 1:0:1; 1:1:1; 5:1:1; 10:1:1; and 20:1:1 with observation on the population development of their progeny. All the experiments were done in the laboratory. The data were analyzed statistically for their significant differences (P<0.05) respectively. Results. The results showed that the LD50 of Gamma Co-60 irradiation was 17.5 krad. The gamma irradiation dose of 17.5 krad caused sub-sterility (semisterility) in the males of Ae. albopictus, the mating capacity decreased 4% and the reproductive capacity decreased 45.4 %. In the males irradiation of next generation (F1), the mating capacity decreased 7.7% and the reproductive capacity decreased 76,2 %. The mating competitiveness test with ratio of 5:1:1 (males irradiation : normal males : normal females) caused a 54.6% reduction of their progeny, in ratio of 10:1:1 caused a 75.3% reduction, and in ratio of 20:1:1 caused an 81.4% reduction. Conclusion. The irradiation of gamma Co-60 at a dosage of 17.5 krad caused sub-sterility (semisterility) in the males of Ae. albopictus, the decreasing capacity of mating and reproductive, and the reduction of their population.

Kata Kunci : Aedes albopictus, gamma Co-60, tehnik jantan mandul, pengendalian hayati, genetika reproduksi, sterile male technique, genetic control, genetic reproduction