Gayabyeo, a Tongil-type rice variety, has been known to be resistant to the brown planthopper (BPH) in Korea. For genetic analysis of BPH resistance of Gayabyeo, we developed an F2 and F3 population derived from a cross between Gayabyeo and Taebaegbyeo which is a Tongil-type BPH susceptible rice variety. Based on the previously detected 284,501 putative SNPs between Gayabyeo and Taebaegbyeo, 99 cleaved amplified polymorphic sequences (CAPS) markers were developed, and they have been used for genotyping 180 F2 plants. By comparison of resequencing data of Gayabyeo and the sequences of already reported BPH resistance genes (Bph3, BPH9, Bph14, BPH18, BPH26), it was revealed that Gayabyeo has Bph3 and BPH26 resistance genes. Two InDel markers, Bph3IND and BPH26IND, were developed, which can be used as selection markers in breeding program aiming at introducing BPH resistance genes of Gayabyeo into Korean high quality japonica rice varieties. In addition, BPH bioassay was performed with 180 F3 lines for BPH resistance QTL analysis. Two major QTLs were found on chromosome 4 and 12. The regions of these two QTLs included Bph3 and BPH26, which also supported that Gayabyeo has Bph3 and BPH26 resistance genes. These results would be useful in accelerating development of various BPH-resistant high quality japonica rice varieties in Korea.

This experiments were carried out to know the response to Brown Planthopper(BPH) resistance genes at rice seedling stage using Biotype 1 for develoment of resistant cultivars. Varieties with Bph1, Bph3 and Bph18 genes showed a very strong resistance response, BpH2, Bph6, bph7 and Bph9 genes exhibited moderate resistance. Bph5 and Bph8 gene retention varieties and Nampyeongbyeo showed a very weak sensitivity in response to BPH. After 72 hours, Nampyeong(no gene) and IR72(Bph3 gene) were showed a feed-preference 690% and 0%, respectively. Results of Antixenosis and seedling resistance response to BPH were grouped into similar by specific resistance genes. Ten days after inoculation, BPH survival rate of vareities with resistance genes were below 30%, whereas Nampyeongbyeo was more than 70%. The results showed that Bph3 and Bph18 genes are highly resistant response against BPH, these genes are very useful for improve the rice cultivars with various resistance genes

‘Anmi’ is a new BPH (Brown planthopper) resistant japonica rice cultivar possessing the Bph18 gene derived from wild rice, Oryza australiensis and high yield potential with good grain quality. ‘Anmi’ was derived from a cross ‘Junam’ and ‘IR65482-7-216-1-2’ by a molecular marker assisted backcross breeding. The introgression line ‘IR65482-7-216-1-2’, the source of the Bph18 gene, was used as the donor parent for BPH resistance and ‘Junam’, a BPH-susceptible elite japonica cultivar with good grain quality, was used as the recurrent parent. ‘Anmi’ was developed by three times backcross the F1 plants with ‘Junam’. The heading date of ‘Anmi’ is August 15 in central plain area, which is 5 days later than that of ‘Hwaseong’. It has 77 cm in culm length, 21 cm in panicle length. The number of spikelets per panicle is more than that of ‘Hwaseong’ and 1,000 grain-weight of brown rice is 22.1 g which is less than 22.7 g of ‘Hwaseong’. Milled rice kernel of ‘Anmi’ is clear in appearance, low in amylase content and excellent in palatability of cooked rice. ‘Anmi’ shows resistance to BPH, leaf blast disease, bacterial blight, rice stripe disease but susceptible to other virus disease and insect pest. The milled rice yield performance of ‘Anmi’ is about 5.76 MT/ha in local adaptability test for three years. This cultivar is adaptable to central plain area of Korea.