著者

Kenji Fujino Yoshihiro Kawahara Kanako O. Koyanagi Kenta Shirasawa

出版者

Japanese Society of Breeding

雑誌

Breeding Science (ISSN:13447610)

巻号頁・発行日

pp.20089, (Released:2021-02-17)

被引用文献数

8

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Understanding genetic diversity among local populations is a primary goal of modern crop breeding programs. Here, we demonstrated the genetic relationships of rice varieties in Hokkaido, Japan, one of the northern limits of rice cultivation around the world. Furthermore, artificial selection during rice breeding programs has been characterized using genome sequences. We utilized 8,565 single nucleotide polymorphisms and insertion/deletion markers distributed across the genome in genotype-by-sequencing for genetic diversity analyses. Phylogenetics, genetic population structure, and principal component analysis showed that a total of 110 varieties were classified into four distinct clusters according to different populations geographically and historically. Furthermore, the genome sequences of 19 rice varieties along with historic representations in Hokkaido, nucleotide diversity and FST values in each cluster revealed that artificial selection of elite phenotypes focused on chromosomal regions. These results clearly demonstrated the history of the selections on agronomic traits as genome sequences among current rice varieties from Hokkaido.

著者

Kenji Fujino Utako Yamanouchi

出版者

Japanese Society of Breeding

雑誌

Breeding Science (ISSN:13447610)

巻号頁・発行日

pp.19112, (Released:2020-06-05)

被引用文献数

6

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The optimization of flowering time is a key aspect in maximizing grain productivity in rice. Allelic variations in genes for flowering time are major drivers in the wide adaptability of cultivated rice around the world. Here, we identified a novel allele of flowering time gene Grain number, plant height and heading date 7 (Ghd7). Loss-of-function ghd7, Ghd7-0a, is important for extremely early flowering time for adaptability to cultivation in Hokkaido, Japan. However, the rice variety Sorachi lacks a key functional nucleotide polymorphism of Ghd7, which results in a loss of function of the gene. Based on the sequence of Ghd7 allele in Sorachi, we identified the insertion of a transposon-like sequence at an upstream site of Ghd7. Segregation analysis using an F2 population derived from the cross between Hoshinoyume and Sorachi demonstrated that the Ghd7 locus contributed to extremely early flowering time in Sorachi. This Ghd7 allele in Sorachi showed a weak function in terms of delay of flowering time, compared with loss-of-function allele, and a distinct distribution in northern Japan.