Institute of Crop Science, NARO

Sweetpotato and Miscellaneous Crops Breeding Unit

Sweetpotato (Ipomoea batatas) and miscellaneous crops are indispensable to the Japanese menu such as yaki-imo (baked sweetpotato) and soba (buckwheat noodle), and are also necessary for the maintenance of crop rotation. The main purpose of our unit is to breed new excellent varieties of sweetpotato and miscellaneous crops, and to find new methods of utilization in collaboration with the local research centers of NARO.

We pursue the breeding of sweetpotato to develop cultivars suitable for table use and processing. Important breeding objectives are high quality and resistance to soil-borne diseases. Recently, we released new sweetpotato cultivars including "Himeayaka" culltivar with compact size roots for a single meal, "Aikomachi" cultivar for table use and processing confectioneries, and "Hoshikogane" cultivar for processing as hoshi-imo (dried sweetpotato). We also elucidate the factors associated with eating quality of cooked sweetpotato, depending on its sweetness and texture.

For buckwheat (Fagopyrum esculentum), our target is to breed new varieties suitable for double cropping to be sown in spring and summer continuously, and to develop new breeding method by using DNA marker system and self-compatibility. For medicinal crops, we breed new adlay (Coix lacryma-jobi) variety with disease tolerance and high seed quality, and breed experimentally new Angelica acutiloba showing stable amount of effective factors in its root. We have released high-lignan sesame (Sesamum indicum) varieties such as "Nishikomaru", and we are now trying to find new materials with even higher lignan content.

Unit Leader

Naoki OGATA Project leader of the miscellaneous crops and the sugar crops

Unit Members

Research Topic
Kenji KATAYAMA Senior Principal Researcher Project leader of the sweetpotato breeding and studying the improvement of sweetpotato starch properties
Yoshiyuki NAKAMURA Principal Researcher Sweetpotato eating quality
Toshikazu KURANOUCHI Principal Researcher Sweetpotato breeding, Sweetpotato quality, Pest resistance
Masako KATO Principal Researcher Sesame and adlay (Job's-tears) breeding for high seed quality and yield
Katsuhiro MATSUI Principal Researcher Improving buckwheat yield and quality, Regulation of flavonoid biosynthesis in buckwheat, Developing buckwheat breeding systems with self-compatibility lines
Mio NISHINAKA Researcher Sweetpotato breeding, Quality analysis and assessment
Ry?ma TAKESHIMA Researcher Improving buckwheat yield and quality, Regulation of photoperiodic response (flowering and maturity time)in buckwheat

Research Publications

    • Matsui K et al. (2016) Isolation and characterization of genes encoding leucoanthocyanidin reductase (FeLAR) and anthocyanidin reductase (FeANR) in buckwheat (Fagopyrum esculentum). J Plant Physiol 205: 41-47.
    • Yasui Y, Hirakawa H, Ueno M, Matsui K, Katsube-Tanaka T, Jung YS, Aii J, Sato S, Mori M (2016) Assembly of the draft genome of buckwheat and its applications in identifying agronomically useful genes. DNA Res 23:215-224.
    • T. Kuranouchi et al. (2016) Breeding erect plant type sweetpotato lines using cross breeding and gamma-ray irradiation. Breed Sci 66: 456-461.
    • Ogata N and Kato M (2016) Half-diallel analysis for sesamin and sesamolin contents of sesame (Sesamum indicum L.) seeds. Jpn J Crop Sci 85(3):302-308 (in Japanese).
    • Nakamura Y et al. (2016) Effect of starch pasting temperature on remaining total ascorbic acid content in steamed sweetpotatoes. J Jpn Soc Food Sci Tech 63:433-438 (in Japanese).
    • Ogata N et al. (2015) Phytoremediation of radioactive cesium contaminated soil by cultivation of Amaranthus spp. Jpn J Crop Sci 84(1):9-16 (in Japanese).
    • Katayama K et al. (2015) Inheritance of low pasting temperature in sweetpotato starch and the dosage effect of wild-type alleles. Breed Sci 65(4):352-356.
    • Nakamura Y et al. (2014) The effects of beta-amylase activity and starch pasting temperature on maltose generation in steamed storage roots of sweetpotato. J Jpn Soc Food Sci Tech 61:577-585 (in Japanese).

  • Nakamura Y et al. (2014) Mechanism for maltose generation by heating in the storage roots of sweetpotato cultivar "Quick Sweet" containing starch with a low pasting temperature. J Jpn Soc Food Sci Tech 61:62-69 (in Japanese).
  • Kuranouchi T et al. (2014) Annual variation and varietal difference in sweetpotato soil rot (Streptomyces ipomoea) resistance. Breed Res 16: 147-150 ( in Japanese).
  • Kato M et al.(2012) A new Job's-tears cultivar "Hatokirara". Bull Tohoku Agric Res Cent 114: 1-10 (in Japanese).
  • Katayama K et al. (2011) Resistant and digestible starch contents in sweetpotato cultivars and lines. J Appl Glycosci 58:53-59.