We evaluated the distribution pattern of tannin in 164 sorghum breeding lines and the inhibition rates of amylase, protease, and lipase in sorghum lines with different tannin concentrations. Tannin was existed in the testa of sorghum grain. The tannin content in whole grain of Nampungchal sorghum was 11.54 mg/g, and that in grain (milling rate 73%) and bran fractions was 4.57 mg/g and 28.71 mg/g, respectively. The inhibition rate of α-amylase, α-glucosidase, and β-glucosidase in sorghum lines with tannin was higher than that in sorghum lines without tannin. The inhibition rate of α-glucosidase was greater than 97% in sorghum lines with tannin. The inhibition rate of protease ranged from 20% to 70% in the sorghum lines, showing no discernable trends in tannin content. Lipase inhibition was either very low or not observed and did not seem to correlate with tannin concentration.

The green rice leafhopper (GRH), Nephotettix cincticeps Uhler, is one of the most serious insect pests affecting cultivated rice (Oryza sativa L.) in temperate regions of East Asia. To understand the genetic basis of the GRH resistance, a F2 population derived from across between a highly resistant variety,Cheongnam and a susceptible variety, Junambyeo was analyzed by genetic analysis and association mapping. GRH resistance was evaluated using the F2 populations. The results showed that a single dominant gene in Cheongnam. DNA from 22 F2 individuals being either resistant or susceptible were pooled to produce bulk resistant and bulk susceptible DNA samples. Parents and bulks were screened with 192 SSR markers and twolinked SSRmarker, RM6082 and RM20145 were identified.Subsequent mapping in the original mapping population showed that thelocusis flanked by the SSR markers, RM20130 and RM20152 on chromosome 6. To physically map this locus, the-linked markers were landed on the artificial chromosome clones of the reference cv., Nipponbare, released by the International Rice Genome Sequencing Project. The DNA markers found to be closely linked to Grh3 would be useful for marker-assisted selection for the improvement of resistance to GRH in rice.