Inheritance of a Growth Characteristic of Precocious Restorer Rice Line, DR02

A dominant early maturing trait was identified in DR02 rice bred from T251 and 02K511. Heading dates of the hybrid progenies from DR02 crossed with 6 medium or late maturing varieties, including Minghui 86 and Minghui 63, were analyzed to study the inheritance of the growth characteristic. It was found that the heading dates of F₁ progenies were earlier than those of their mid-parents. The heading dates of F₂ populations from DR02 crossed with Shuangkangmingzhan and 9311 had twin peaks, while those of F₂ from DR02 crossed with the other 4 parents exhibited a unimodal distribution with closely clustered values. The segregation ratio between the early heading and the late heading plants was 3:1 for the F₂ population of DR02 crossed with Yuejingsimiao 2 and Shuangkangmingzhan, while those of other combinations were significantly and extremely significantly different. It suggested that the early maturing trait of DR02 could be largely controlled by a single relatively dominant QTL.