Abstract:

Leaf roller is one of the most important insect pests that affect the high and stable yield of rice. It is of significance to screen and cultivate resistant (tolerant) varieties to conduct green control of rice leaf roller. Identification of resistant (tolerance) parents is the basis of insect-resistant breeding. From 2015, under the field condition in Lingshui County and Luxian County for 4 years, the responses of insect resistant ‘A232’, its progeny ‘Luhui 317’, and susceptible ‘F77’ to RLR and RSLR were observed through plot contrast test, respectively. The significant difference of leaf roll rate among the tested materials was tested. The results showed that the leaf roll rate of ‘F77’ in 2015 was 10.5%, 8.0% and 9.6% higher than that of ‘A232’ and ‘Luhui 317’, and the leaf roll rate of ‘F77’ in 2016 was 74.9%, 20.3% and 28.0% higher than that of ‘A232’ and ‘Luhui 317’, respectively. The difference of the two years reached 5% significant level. The leaf roll rate of ‘A232’, ‘Luhui 317’ and ‘F77’ of autumn sowing in 2017 was all above 90%, and their differences were not significant (P>0.05). However, the rate of grade 0 leaves of ‘A232’ and ‘Luhui 317’ was 4.4% and 8.7% higher than that of ‘F77’. The rate of grade 1 leaves of ‘A232’ and ‘Luhui 317’ was 11.7% and 22.1% higher than that of ‘F77’, the rate of grade 3 leaves of ‘A232’ and ‘Luhui 317’ was 16.0% and 30.4% lower than that of ‘F77’. The difference between them reached 5% significant level. ‘A232’ and ‘Luhui 317’ showed obvious tolerance to rice leaf roller in Luxian (P<0.05). After tests in different seasons and sites for years, ‘Luhui 317’ could be used as a variety to resist rice leaf roller. ‘A232’ is a variety that has moderate resistance to striped rice borer and tryporyza incertulas and has tolerance to rice leaf roller and rice stripe leaf roller.

Key words: rice, insect-resistant germplasm, rice leaf roller, rice stripe leaf roller, leaf roll rate, tolerance to insects