Development and Genetic Analysis of Near Isogenic Lines for Opaqueness of Endosperm in Rice

Abstract

Rice plants segregating for opaque endosperm were selected and tested in every generation from F5 to F9 of a CB243/IR50 cross. Six near isogenic lines(NILs) showing diference in opaqueness, of which three lines have opaque endosperm with theothers having translucent endosperm, were selected among F9 lines. No diferences were found in plant growth characteristicsexcept for 1,000-grain weight between opaque and normal translucent endosperm NILs. F2 plants of two crosses between opaqueand translucent endosperm NILs segregated into 1 homozygous opaque : 2 segregating : 1 homozygous translucent endosperm, andthis result indicates that the opaqueness of rice grain folows the single gene inheritance. Also genetic analysis showed that opaqueendosperm was recessive to translucence. Pedigree lines or F2 plants bearing opaque rice grain showed low amylose content(AC),while translucent grain showed high AC. It seems that the opaqueness of rice grain of a parental variety CB243 is closely relatedwith low AC.