pedigree selection
1.In 1973 the USA Labelle was crossed with Zhen-Long-Xuan(early maturing indica ). Selection was conducted from F2 by using pedigree method. In 1977 a plant with smooth leves, dwarf stalk,exserted stigma and early flowering was selected out from F5 population to make test-cross with Fu-yu 1 A (a sterile line of BT type ) in pairs.
