Information mengenai respons biologi wereng batang coklat (WBC), Nilaparvata lugens (Stl) terhadap tanaman padi sangat diperlukan dalam upaya pengembangan varietas tanaman padi tahan WBC. Penelitian dilakukan mulai Juni 2010 hingga April 2012 di Kebun Percobaan Muara, Balai Besar Padi, serta di Laboratorium Fisiologi dan Toksikologi Departemen Proteksi Institut Pertanian Bogor. Penelitian bertujuan untuk mengetahui respons biologi WBC terhadap faktor-faktor biokimia tanaman padi. Respons biologi WBC yang diamati adalah preferensi hinggap, aktivitas atau kemampuan makan, dan analisis tabel kehidupan. Faktor-faktor biokimia seperti kandungan sukrosa dan asam oksalat dianalisis di Balai Besar Penelitian Bioteknologi dan Sumber Daya Genetika, Bogor. Varietas padi yang digunakan adalah TN1 (tanpa gen tahan), IR26 (Bph1), IR42 (bph2), IR64 (Bph1+), IR74 (Bph3), PTB33 (bph2, Bph3) dan Inpari13 (gen ketahanan belum diketahui). WBC memperlihatkan reaksi non-preferensi terhadap varietas padi yang tahan. WBC memiliki kemampuan makan tertinggi pada padi varietas pembanding rentan TN1(tanpa gen tahan) dan terendah pada varietas pembanding tahan PTB33. WBC yang diinfestasi pada varietas rentan memiliki laju pertumbuhan populasi intrinsik, reproduksi bersih yang lebih tinggi, dan waktu penggandaan populasi lebih pendek. Varietas padi yang tahan WBC memiliki kandungan asam oksalat lebih tinggi dan kandungan sukrosa lebih rendah dibanding varietas rentan. Kedua faktor biokimia ini berkontribusi dalam mekanisme ketahanan tanaman padi terhadap WBC.
Biological Responses of Brown Planthopper, Nilaparvata lugens Stl (Hemiptera: Delphacidae) to Biochemical Factors of Rice. In developing rice varieties resistant to brown planthopper (BPH), information on responses of the BPH to the rice plants were needed. The aim of the research was to study the biological responses of BPH on biochemical factors of some rice varieties. The study was conducted on June 2010 to April 2012 in Muara Research Station, of the Indonesian Center for Rice Research (ICRR) and at Laboratory of Physiology and Toxicology, Plant Protection Department, Bogor Agriculture University. The biological responses of the BPH to rice varieties were studied in terms of adult settling preference, feeding activity using the honeydew test, and life table analysis. The biochemical factors of the rice varieties, namely sucrose and oxalic acid contents were analyzed. Rice varieties TN1 (no resistance gene), IR26 (Bph1), IR42 (bph2), IR64 (Bph1+), IR74 (Bph3), PTB33 (bph2+Bph3), and Inpari13 (unknown resistance gene) were used in this study. The BPH showed similar non-preference reactions to the resistant varieties and Inpari13 for settling. Feeding activity of the adult female BPH was the highest on the susceptible variety TN1 and the lowest on the resistant variety PTB33. The highest mortality of BPH occurred at larval stages, especially in the first and second instars. The intrinsic rate of increase (rm) and net reproductive rate (Ro) of the BPH were higher on the susceptible variety TN1, but the doubling time (DT) was shorter than those on the resistant varieties. The resistant variety PTB33 contained high oxalic acid and low sucrose. On the contrary, the susceptible variety TN1 contained low oxalic acid and high sucrose. These biochemical factors contributed in rice plant resistance to BPH.
