"Germplasm lacking lipoxygenase-3 in a wide diversity of rice [Oryza sativa] genetic resources in Yunnan, China."
2002
"Ise, K. (Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki) | Suzuki, Y. | Xiong, J. | Dai, L. | Ye, C. | Kudo, S. | Maekawa, M. "
"China's Yunnan province is a center for genetic diversity in Asian cultivated rice. We have conducted a collaborative research project for rice breeding using a wide diversity of genetic resources from Yunnan and Japan-since 1982. We screened the germplasm collection from Yunnan for lipoxygenase-3 (LOX-3) content in embryos by using monoclonal antibodies against LOX-3. The lipoxygenase enzyme catalyzes the oxidation of unsaturated fatty acids containing a 1,4-pentadiene structure into conjugated hydroperoxy fatty acids. The lack of lipoxygenase enzyme in rice grains may reduce oxidative deterioration during storage. We detected 22 varieties lacking LOX-3, the major component among isozymes in rice seeds, after screening 108 varieties of Yunnan rice genetic resources. Most of the varieties without LOX-3 belonged to Japonica upland rice, and to Types-4 and 6, based on esterase isozyme genotypes. Varieties without LOX-3 displayed the following agronomic characteristics: early heading, round grains, lower amylose content in the endosperm, and glabrous leaves and hulls. The lack of LOX-3 was inherited as a single recessive trait in the cross between ""CI-115"" lacking LOX-3 and ""Norin 20"" with LOX-3 activity. ""CI-115"" is a pure line selected from the indigenous upland variety ""Chongtui"". No tight linkage was observed between the lack of LOX-3 trait and the red pericarp trait derived from ""CI-115""."
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