Elucidation of Factors to Fruit Set Failure in Self-Pollination of Tetraploid Rocoto Peppers Obtaining Self-Compatibility.

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K06017
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39030:Horticultural science-related
• Research Institution: Kyushu University
• Principal Investigator: Miyajima Ikuo 九州大学, 熱帯農学研究センター, 学術特定研究者 (20182024)
• Co-Investigator(Kenkyū-buntansha): 水ノ江 雄輝 九州大学, 農学研究院, 助教 (50759206)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 四倍体 / ロコトトウガラシ / 高温障害 / 自家不和合性 / 自家和合性 / コルヒチン処理

Outline of Final Research Achievements

Rocoto pepper (rocoto), native to the Andes region of South America, is a new pungent pepper with high water content in its pericarp, which allows the use of fresh fruits. The problem was to overcome the self-incompatibility of this species in order to use it as a horticultural crop. In contrast, tetraploid rocoto obtained by colchicine treatment was found to be self-compatibility, but the low self-pollination rate was a new problem.
The results of this study revealed that pollen germination of rocoto was suppressed under high temperature conditions, which was considered to be the main reason for the low self-pollination rate. The tetraploid rocoto showed a self-pollination rate of nearly 65% under appropriate temperature conditions, indicating the practicality of tetraploid rocoto.

Free Research Field

園芸学

Academic Significance and Societal Importance of the Research Achievements

本研究により，四倍体ロコトの自家受粉での着果不良の主な要因は，自家不和合性に関するSハプロタイプをヘテロ接合でもつ花粉だけしか受精にかかわれない（受精可能な花粉量が少ない）ためではなく，環境要因（高温）である可能性が示された．
ロコトは冷涼な気候を好むので，耕作放棄地の多い我が国の中山間地での栽培に適した作物といえる．さらに，四倍体ロコトの新鮮果実は果皮が厚くジューシーなため，ドレッシングや酢漬け（ピクルス）等の加工用トウガラシとしての利用が期待される．したがって，農産物の６次産業化を目指す地域では今後注目される作物と思われる．