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研究成果

New Rice Variety “Besalohy” Developed in Madagascar
～Utilizing a Koshihikari-Derived Panicle-Number-Increasing Gene to Achieve a 9% Yield Increase Under Low-Fertility Conditions～

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2026-10-22Japan International Research Center for Agricultural Sciences (JIRCAS)
Madagascar National Center for Applied Research in Rural Development (FOFIFA)
 

ポイント

 

  • A new rice variety, “Besalohy,” was developed by applying Japanese breeding expertise to the local leading variety, “X265.” It has been registered in Madagascar and is now in the stage of widespread adoption.
  • In productivity tests conducted across 21 different environments, the number of panicles increased by an average of 21% compared to the main variety. Yield increases of 8-10% were confirmed under all three fertilization treatments: no fertilizer, compost application, and compost plus chemical fertilizer application.
  • The variety is expected to contribute to stable rice production in low-fertility paddy fields, higher rural incomes, and improved food security.

 

Overview

Rice is the staple food of Madagascar. However, paddy fields with low soil fertility, particularly those deficient in nitrogen and phosphorus, are widespread throughout the country. As a result, there has been a strong need for rice varieties capable of maintaining stable yields even under low-input conditions. The Japan International Research Center for Agricultural Sciences (JIRCAS), in collaboration with the Madagascar National Center for Applied Research in Rural Development (FOFIFA), has developed a new rice variety called “Besalohy,” which demonstrates increased productivity in low-fertility paddy fields. The variety has now been officially registered in Madagascar.

“Besalohy” means “many panicles” in Malagasy. It was developed by introducing the MP3 gene locus1 , which increases the number of panicles, from Japan’s leading rice variety “Koshihikari” into Madagascar’s leading rice variety “X265.” Through repeated backcrossing2 and DNA marker-assisted selection3, researchers successfully retained the key agronomic characteristics of X265 while adding the ability to produce more panicles even under low-fertility conditions.

From 2024 to 2025, yield trials were conducted at seven locations across Madagascar’s Central Highlands and the northwestern and eastern regions, using three fertilization treatments: no fertilizer, compost application, and compost plus chemical fertilizer application. The trials covered a wide range of production environments, where yields of X265 ranged from 1.80 to 6.37 tons per hectare. Results showed that compared with X265, “Besalohy” increased panicle number by an average of 21% and grain yield increased increased by an average of 9%. These advantages were observed even under the no-fertilizer treatment, where yields of X265 were relatively low. In taste evaluations conducted with 38 farming households, “Besalohy” received higher ratings than X265 in all categories, including appearance before and after cooking, aroma, and overall eating quality.

Going forward, JIRCAS, FOFIFA, and Madagascar’s Ministry of Agriculture and Food Sovereignty will collaborate in the production and dissemination of certified seed of “Besalohy.” The variety is expected to contribute to the stable production of rice, Madagascar’s staple food, improved rural incomes, poverty reduction, and food security.
 

Related Information

  • Development of Sustainable Rice Cultivation and Food Production System in Africa (FY2021–FY2025)
  • Climate-Smart Rice Systems Integrating Forest Functions in Africa (FY2026–present)
  • Registered Variety Name: Besalohy
    (Alternative name: FOFIFA X265-MP3)
  • Date of Registration Notification: August 28, 2026
  • Official Registration Document Number: N129/26-MiASA/SG/DGA/SOC
Funding
JIRCAS Operating Grant Projects
SATREPS Project (Science and Technology Research Partnership for Sustainable Development)
Breakthrough in Nutrient Use Efficiency for Rice by Genetic Improvement and Fertility Sensing Techniques in Africa (FY2017–FY2021)
Variety Registration Information

問い合わせ先など

国際農研 (茨城県つくば市) 理事長　長谷川利拡

研究推進責任者 : 
プログラムディレクター　藤田泰成
研究担当者 : 
生産環境・畜産領域 主任研究員　髙井俊之
生産環境・畜産領域 プロジェクトリ―ダー　辻本泰弘
広報担当者 : 
広報連携ユニット長　丸井淳一朗
プレス用 e-mail : info-pr@jircas.go.jp

Glossary

1 the MP3 gene locus
A gene locus that promotes tillering in rice and increases the number of panicles. It was identified in the Japanese rice variety Koshihikari, and its introduction into indica rice varieties widely cultivated in tropical regions has been shown to increase both panicle number and grain number by approximately 20%.
Reference: FY2023 JIRCAS Research Highlights: A quantitative locus, MP3, which increases panicle number, enhances grain yield under an elevated atmospheric CO2 environment (https://www.jircas.go.jp/en/publication/research_results/2023_b07)
2) 連続戻し交配
2品種間で交配した子 (雑種第一代) およびその後代に、改良の基礎とする親品種を繰り返し交配する方法です。親品種の優れた特徴を保ちながら、目的とする遺伝子を導入するために用います。
3) DNAマーカー支援選抜
DNA配列の違いを目印として、目的の遺伝子や形質を持つ個体を効率的に選ぶ育種技術です。
4) 分げつ
イネ科植物の根元から枝分かれして生じる新しい茎のことです。多くの場合、それぞれの茎に穂が形成されます。

 

担当研究者の声

マダガスカルの研究者と共にイネ育種に取り組む髙井主任研究員
 

生産環境・畜産領域　髙井俊之

2018年に初めてマダガスカルを訪れた際、痩せた水田で稲穂が極めて少ない光景に衝撃を受けました。それから8年を経て、痩せた水田でも稲穂を増やす新品種「Besalohy」の育成に携われたことを大変感慨深く思います。今後はその普及にも尽力し、マダガスカルのイネ生産向上に役立てれば幸いです。

(写真: マダガスカルの研究者とイネ育種のための交配に取り組む髙井主任研究員)

参考図表

Fig1

図1　親品種「X265」と新品種「Besalohy」の染色体構成

横軸の1～12はイネの染色体番号を示す。黒色の領域は「コシヒカリ」由来の染色体領域で、穂数増加遺伝子MP3を含む。

photo1

写真1　親品種「X265」と水稲新品種「Besalohy」の草姿

(左)親品種「X265」、(右) 新品種「Besalohy」。

table1

表1　生産力試験における「Besalohy」の穂数（本/m2）

table2

表2　生産力試験における「Besalohy」の精籾収量（t/ha）

table3

表3　農家による「Besalohy」食味評価

photo2

写真2　新品種「Besalohy」のリリース式典

(左) ラジャウナリソン首相による祝辞 (写真: マダガスカル共和国農業食料主権省提供)。
(右) 集合写真 : 左から ラミンド農業食料主権大臣、ラヴニマナンツァ高等教育科学技術大臣、戸島特命全権大使、ラジャウナリソン首相、FOFIFA所長、国際農研研究担当者、国際農研研究担当者、FOFIFA研究担当者。

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