Jurnal Perlindungan Tanaman Indonesia (Jul 2008)

Susceptibility of The Asian Corn Borer, Ostrinia furnacalis, to Bacillus thuringiensis Toxin CRY1AC

  • Aye Kyawt Kyawt Ei,
  • Y. Andi Trisyono,
  • Witjaksono Witjaksono

DOI
https://doi.org/10.22146/jpti.11876
Journal volume & issue
Vol. 14, no. 1
pp. 35 – 39

Abstract

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The larval susceptibility of the Asian corn borer, Ostrinia furnacalis (Guenee) (Lepidoptera: Crambidae), to a Bacillus thuringiensis protein (Cry1Ac) was evaluated using insect feeding bioassays. The founding population of O. furnacalis was originally collected from the experimental station of UGM at Kalitirto and had been reared in the laboratory for three generations using an artificial diet “InsectaLf”. The tested instars were exposed on diets treated with a series of concentrations of Cry1Ac for one week. The LC50 values on the seventh day after treatment for 1st, 2nd, 3rd and 4th instars were 7.79, 21.12, 113.66, and 123.17 ppm, respectively, showing that the higher the instars the lesser the susceptibility to Cry1Ac. When the neonates were exposed to sublethal concentrations of Cry1Ac (0.0583, 0.116, and 0.5830 ppm), growth and development of the surviving larvae were inhibited. The fecundity and viability of females produced from treated larvae decreased with increasing the concentrations. These findings indicate that Cry1Ac is toxic to larva of O. furnacalis and has chronic effects to larvae surviving from Cry1Ac ingestion. Kepekaan larva penggerek batang jagung Asia, Ostrinia furnacalis (Guenee) (Lepidoptera: Crambidae), terhadap protein Bacillus thuringiensis Cry1Ac diuji dengan metode celup pakan. Larva berasal dari pertanaman jagung di KP-4, UGM di Kalitirto dan telah dikembangbiakkan di laboratorium menggunakan pakan buatan (InsectaLF) selama tiga generasi sebelum digunakan untuk pengujian. Larva O. furnacalis yang diuji dipaparkan pada pakan buatan yang telah dicelupkan pada seri konsentrasi Cry1Ac. Nilai LC50 pada hari ketujuh setelah perlakukan untuk instar 1, 2, 3, dan 4 berturut-turut adalah 0,79; 21,12; 113,66; dan 123,17 ppm. Hal ini menunjukkan bahwa instar yang semakin tinggi tingkat kepekaannya terhadap Cry1Ac semakin menurun. Larva yang baru menetas dan diberi pakan yang telah dicelupkan pada konsentrasi sublethal Cry1Ac sebagian akan mati, sedangkan larva yang hidup pertumbuhan dan perkembangannya terhambat. Fekunditas dan vialibitas serangga betina hasil dari larva yang diperlakukan dengan Cry1Ac menurun. Penelitian ini menunjukkan bahwa Cry1Ac toksik terhadap larva O. furnacalis dan juga mempunyai efek kronik terhadap larva yang tetap hidup setelah memakan toksin.

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