The objective of the present invention is to provide: a new cultivar of rice that matures earlier than an original cultivar and a method for causing the earlier maturing of rice individuals. The present invention relates to: rice cultivar Koshihikari kazusa 6 go, which has a cultivar registration application number of 25587 a progeny individual obtained by hybridizing two individuals selected from the group consisting of an individual of the aforementioned cultivar and a progeny individual thereof and a method that is for causing the earlier maturing of rice individuals and that is characterized by replacing the region of the third chromosome of a rice individual corresponding to the region containing base number 31,720,064 to 31,724,043 in the third chromosome of rice cultivar Nipponbare with a chromosome fragment comprising the corresponding region of rice cultivar Habataki or rice cultivar Koshihikari kazusa 6 go.本発明は、元品種よりも早生化されたイネの新品種、及びイネ個体を早生化する方法の提供を目的とする。本発明は、品種登録出願番号が第25587号であるイネ品種コシヒカリかずさ6号、前記記載の品種の個体及びこの後代個体からなる群より選択される2個体を交配して得られる後代個体、並びに、イネ個体の第3染色体中の、イネ品種日本晴の第3染色体中の31,720,064番目の塩基から31,724,043番目の塩基までを含む領域に相当する領域を、イネ品種コシヒカリかずさ6号又はイネ品種ハバタキの当該領域からなる染色体断片に置換することを特徴とする、イネ個体を早生化する方法に係る。【選択図】なし
