Non-preference mechanism of resistance in rice germplasm accessions to whitebacked planthopper Sogatella furcifera (horvath)

A total of 1010 germplasm accessions collected from different parts of India were mass screened for their reaction to Whitebacked planthopper, Sogatella furcifera (Horvath) by standard seedbox screening technique during 2016–2018 at ICAR-Indian Institute of Rice Research, Hyderabad. 43 accessions exhibited a damage score (DS) ranging from 1.39 to 5.0 and were designated as resistant and moderately resistant to WBPH, and 967 accessions were susceptible (DS 5.1 to 9.0). Two germplasm accessions viz., IC 75864 (DS-1.39), IC 215295 (DS-2.65) were resistant and 41 accessions were moderately resistant (DS 3.1 to 5.0). The selected resistant accessions were assessed for their feeding preference by WBPH by measuring feeding/probing marks and honeydew excretion area. The resistant accessions exhibited more number of probing marks ranging from 4.6 to 24.0/seedling indicating the non-suitability of the accessions for feeding by WBPH. Resistant check MO1 recorded 31.6, PTB33 recorded 17.8 probing marks and susceptible check TN1 recorded 8.2 probing marks/seedling. WBPH fed less and excreted less honeydew on the resistant germplasm accessions indicating their non-preference. Negative correlation existed between resistance and probing marks whereas it is positively correlated with honeydew excretion. The identified resistant germplasm accessions can be used in the breeding programmes to develop WBPH resistant varieties.