Introducing a quantitative trait locus, MP3, improves rice panicle numbers in nutrient-poor soils
Country
Madagascar
Description
The majority of paddy fields in sub-Saharan Africa (SSA) are characterized by nutrient-poor soils. In such fields, tillering in rice plants is severely restricted, which results in a reduced number of panicles and thus a decrease in grain yield. Therefore, genetic improvement to increase rice tillering may ensure sufficient panicles in nutrient-poor soils and thus lead to increase in rice productivity. Because we previously detected a quantitative locus, MP3 (MORE PANICLES 3), to be effective at increasing the number of panicles in nutrient-rich fields, we expected that MP3 will also be effective in enhancing rice productivity in nutrient-poor soils.In this study, we used a high-yielding indica cultivar, Takanari, and its near-isogenic line bearing the MP3 allele derived from a japonica cultivar, Koshihikari (NIL-MP3). They were first grown in pots that contain nutrient-poor soils from Madagascar at various P application rates. The pot experiment demonstrated vigorous tillering in NIL-MP3 compared to Takanari from the early vegetative stage even under low P levels (Fig. 1). We next conducted multiple field trials in Madagascar with a total of 12 experimental conditions using the two varieties. The experiments produced grain yields ranging from 1.3 to 4.1 t ha−1 and panicle numbers ranging from 107 to 270 m−2. The results revealed that NIL-MP3 produced a greater number of panicles and spikelets m−2 (19% and 12%, respectively) than Takanari, with grain yields ranging from 2.0 to 4.1 t ha−1, but not in extremely low yield environments (< 1.3 t ha−1) (Fig. 2).
The results of this study indicate that MP3 is effective at increasing the number of panicles in nutrient-poor soils in SSA. However, utilization of MP3 in conjunction with fertilizer management may be necessary in extremely low yield environments (< 1.3 t ha−1). We are currently introducing MP3 into a local Madagascar cultivar, X265, which is adapted to the environments in SSA, to verify the effect of MP3 on grain yield in such environments.
Figure, table
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Fig. 1. Changes in the number of tillers between Takanari and NIL-MP3 grown in pots that contain nutrient-poor soils in Madagascar at various P application rates.
** and * show significance at 1% and 5% levels, respectively.
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Fig. 2. Comparison of the number of panicles (A) and spikelets (B) between Takanari and NIL-MP3 across 12 field experiments in Madagascar
Yield level shows mean yield between Takanari and NIL-SPIKE in each experiment.
*** shows significance at 0.1% level.
- Affiliation
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Japan International Research Center for Agricultural Sciences Biological Resources and Post-harvest Division
- Classification
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Research
- Program name
- Research Project
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Breakthrough in Nutrient Use Efficiency for Rice by Genetic Improvement and Fertility Sensing Techniques in Africa
- Term of research
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FY2020（FY2017～FY2021）
- Responsible researcher
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Takai Toshiyuki ( Biological Resources and Post-harvest Division )
Tsujimoto Yasuhiro ( Crop, Livestock and Environment Division )
KAKEN Researcher No.: 20588511Asai Hidetoshi ( Crop, Livestock and Environment Division )
KAKEN Researcher No.: 30599064Nishigaki Tomohiro ( Crop, Livestock and Environment Division )
KAKEN Researcher No.: 80795013Ishizaki Takuma ( Tropical Agriculture Research Front )
Sakata Mitsukazu ( Kochi University )
Rakotoarisoa Njato Mickaël ( Centre National de Recherche appliquée au Développement Rural, Madagascar )
- ほか
- Publication, etc.
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Takai T et al. (2021) Crop Science, 61(1):519-528https://doi.org/10.1002/csc2.20344
- Japanese PDF
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2020_B01_A4_ja.pdf290.03 KB
2020_B01_A3_ja.pdf290.92 KB
- English PDF
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2020_B01_A4_en.pdf242.99 KB
2020_B01_A3_en.pdf245.93 KB
- Poster PDF
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2020_B01_poster.pdf220.09 KB
＊ Affiliation at the time of implementation of the study.