title: Inheritance of low pasting temperature in sweetpotato starch and the dosage effect of wild-type alleles.
abstract: Sweetpotato (Ipomoea batatas (L.) Lam.), which is an outcrossing hexaploid, is one of the most important starch-producing crops in the world. During the last decade, new sweetpotato cultivars, e.g. 'Quick Sweet', which have approximately 20°C lower pasting temperature, slower retrogradation and higher digestibility of raw starch than ordinary cultivars, have been developed in Japan. Genetic analysis of these variants with low pasting temperature starch was conducted in this study. Using 8 variants and 15 normal clones, 26 families were generated. The results from analyzing these progenies suggested that this trait is a qualitative character controlled by one recessive allele (designated spt), which is inherited in a hexasomic manner. A dosage effect of the wild-type Spt allele was found for starch pasting temperature, although the effect was not linear. These results will aid breeders to develop sweetpotato cultivars with a range of starch pasting temperatures.
authors.affiliation: NARO Institute of Crop Science , 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 , Japan ; NARO Kyushu Okinawa Agricultural Research Center , 6651-2 Yokoichi, Miyakonojo, Miyazaki 885-0091 , Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Katayama
authors.affiliation: NARO Institute of Crop Science , 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 , Japan ; NARO Hokkaido Agricultural Research Center , 9-4 Shinseiminami, Memuro, Kasai, Hokkaido 082-0071 , Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Tamiya
authors.affiliation: NARO Kyushu Okinawa Agricultural Research Center , 6651-2 Yokoichi, Miyakonojo, Miyazaki 885-0091 , Japan.
authors.forename: Tetsufumi
authors.initials: T
authors.lastname: Sakai
authors.affiliation: NARO Kyushu Okinawa Agricultural Research Center , 6651-2 Yokoichi, Miyakonojo, Miyazaki 885-0091 , Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Kai
authors.affiliation: NARO Institute of Crop Science , 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 , Japan ; Headquarters, National Agriculture and Food Research Organization (NARO) , 3-1-1 Kannondai, Tsukuba, Ibaraki 305-8517 , Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Ohara-Takada
authors.affiliation: NARO Institute of Crop Science , 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 , Japan.
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Kuranouchi
authors.affiliation: NARO Kyushu Okinawa Agricultural Research Center , 6651-2 Yokoichi, Miyakonojo, Miyazaki 885-0091 , Japan ; Headquarters, National Agriculture and Food Research Organization (NARO) , 3-1-1 Kannondai, Tsukuba, Ibaraki 305-8517 , Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Yoshinaga
keywords: gene-dosage effect; inheritance; pasting temperature; polyploid; starch; sweetpotato