Inheritance of Heading Time in Native Japanese Upland Rice, Oryza L.

Abstract

Upland rice has been left without intensive studies on the inheritance of agronomic traits unlike lowland rice and there were very few reports on the genetic analysis of heading time. Since the Lm locus having multiple alleles controls primarily the varietal earliness and lateness of lowland rice (YOKOO et al. 1980), this report examined the role of the Lm locus in heading time of six native upland rice varieties. Under the natural day-1ength, the lowland rice tester lines ER with the early-heading gene Lm^e and LR with the late-heading allele Lm^u headed 84 a:nd 105 days after sowing, respectively. Four upland rice varieties. Kurumi-wase, Hideri-shirazu, Kyushu and Wase-dango-mochi, headed at almost the same time as ER. Kuroka-mochi headed intermediately between ER and LR, and Kirishima did two days later than LR.