Study on early selection method of low-chilling Japanese pear cultivar

Research Project

Project/Area Number	17K15222
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	Horticultural science
Research Institution	Tottori University
Principal Investigator	TAKEMURA Yoshihiro 鳥取大学, 農学部, 講師 (70731545)
Project Period (FY)	2017-04-01 – 2020-03-31
Project Status	Completed (Fiscal Year 2019)
Budget Amount *help	¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000) Fiscal Year 2019: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000) Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000) Fiscal Year 2017: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
Keywords	自発休眠 / 低温要求量 / ニホンナシ / SSRマーカー / 果樹
Outline of Final Research Achievements	Aiming to develop a molecular marker for selecting a low-chilling (LC) Japanese pear cultivar, we performed RAD-seq analysis by next-generation sequencing of the Taiwanese pear (LC), Japanese pear (HC) and their F1 and F2 progenies. Among these polymorphic loci, 120 showed an SNP-index of over 0.8 in LC and HC seedlings of the F2 progenies. The analysis using the BLASTn revealed highly homologous regions to a gene that codes for NAC-domain protein or F-box protein in polymorphic loci with a high SNP-index. Thus, the polymorphic loci identified in this study may play a role as molecular markers to estimate chilling requirements for breaking endodormancy in Pyrus plants.
Academic Significance and Societal Importance of the Research Achievements	近年の暖冬による影響でナシの休眠打破に必要な低温積算量が不足し、世界各地の低緯度地域、並びに日本の西南暖地でも春の開花遅延や発芽不良が散見されており、少低温要求性ニホンナシ品種の育成は急務とされている。果樹類の新品種育成には多大な労力と時間を要するため、有用形質を示す個体を早期に選抜するための分子マーカーの開発が求められており本研究はこれの一助になると期待される。