由於全球氣候暖化造成的影響，台灣甜柿由於所需低溫不足，面臨產量與品質下滑的威脅。選育適應暖化氣候且能在低海拔地區栽種的優質完全甜柿品種，是目前台灣柿子育種的重要目標。由於柿子為六倍體，且日本系統的完全甜柿，其自然脫澀性狀受單一AST基因座控制的隱性遺傳，六套AST基因必須全為隱性的ast對偶基因（aaaaaa）才是完全甜柿，佔雜交育種族群後裔的比例甚低。因此，必須維持龐大的育種族群，耗費大量的空間、人力與經費，才能進行完全甜柿的育種。本研究藉由建立辨別日本系統甜柿ast等位基因與臺灣本土澀柿品種AST等位基因之分子標誌，以加速育種效率。經由測試日本研究團隊Kanzaki等人（2010）、Mitani等人（2014）設計用於辨別日本澀柿品種與甜柿品種之ast/AST基因座之分子標誌，本研究確認使用AST-F/ PCNA-F/ 5R3R、E4/ E9r、7H9F/AST-R、AST-F/ AST-R等PCR引子組合同樣也能用於區分臺灣本土澀柿品種與日本甜柿的ast/AST基因座。這些分子標誌已經在日本柿品種如富有、次郎、花御所、豐原御所、繪御所、甘百目、西村早生、垂枝等，臺灣品種如牛心、石柿、長果柿、鑽石蜜柿、梨山大玉等，並對富有的雜交第一代後裔進行過測試，可以得到相當一致且可信的結果。另外，本研究也針對本土澀柿品種如牛心柿與石柿的AST基因座進行桑格式定序，得到的DNA序列與日本富有甜柿的ast基因座相互比較之後，找到許多DNA序列上的差異，這些差異也將運用於設計新的分子標誌。
Due to global warming, persimmon production in Taiwan is facing the threat of a decline in yield and fruit quality. The selection of high-quality pollination-constant non-astringent (PCNA) persimmons, which can adapt to a warming climate and can be planted in low-altitude areas, is currently an important goal of Taiwan's persimmon breeding. Since persimmons are hexaploidy, and the natural astringency loss of Japanese persimmon fruits is recessively inherited by a single AST locus, the PCNA phenotype is expressed only when all six alleles are recessive for ast (denoted as aaaaaa). Therefore, there is a need to develop molecular markers for discriminating PCNA and non-PCNA genotypes. In this study, we plan to establish molecular markers for Japanese PCNA to accelerate the efficiency of breeding. After testing the molecular markers of ast/AST loci designed by Kanzaki et al. (2010) and Mitani et al. (2014), this study confirmed that markers using primer pairs such as AST-F/PCNA-F/5R3R, E4/E9r, 7H9F/AST-R, or AST-F/ AST-R can also be used to distinguish the ast/AST locus of Taiwan-native astringent persimmon cultivars and Japanese PCNAs. Sanger sequencing has been also performed on the AST locus of Taiwan-native astringent persimmon cultivars. After comparing with the Japanese PCNA cultivar Fuyu, the differences in DNA sequence will also be used to design new molecular markers.
