初探臺灣小米種原之重要農藝性狀與米質

小米(Setaria italica (L.) P. Beauv., foxtail millet)為多種粟類穀物(millet)中栽培第二大宗者，具耐旱性且營養價值高，為世界上許多乾旱地區的主要糧食作物。鑑於小米與同屬的狗尾草(S. viridis, green foxtail)近年來因為成為C_4光合作用系統模式植物，使小米的研究更為蓬勃發展，將對小米的育種與運用有所助益。小米在臺灣的栽種歷史可追溯至5,000年前，對原住民而言是最古老且神聖的作物，在各個不同部落的保存下，臺灣的小米種原具有相當豐富的遺傳多樣性。本研究初步完成133個小米地方品系農藝性狀觀察：株高介於54.7-124.7公分、平均93.7公分；抽穗天數介於53.7-109.5天、平均為75.2天；穗長介於9.6-56.72公分、平均為23.4公分；穗寬介於1.12-3.17公分、平均2.02公分；千粒重介於0.96-2.85公克、平均1.85公克。胚乳的組成主要為澱粉，含量大約75%，分析117個品系之表觀直鏈澱粉含量(apparent amylose content, AAC)，介於0.69-16.92%，63個品系為糯性(＜5%)，34個品系為低直鏈澱粉(5-10%)，20個品系為非糯性(＞10%)，臺灣小米品系屬糯性者居多。不同直鏈澱粉的品系在臺灣的地理分布並不一致，可能原住民對其黏性的偏好所選拔而來。未來期待將本研究之結果，以全基因體關聯性分析(genome wide association study, GWAS)探勘米質和農藝之數量性狀基因座，導入分子輔助育種程序，加速多元化利用之小米品種育成，以提升於臺灣小米於市場中之價值與競爭力。

關鍵字

小米；農藝性狀；直鏈澱粉含量

並列摘要

Foxtail millet (Setaria italica (L.) P. Beauv.), one of major staple foods in arid areas, is the second largest millet crops and widely adapted to diverse environments. Foxtail millet is a traditional crop for Taiwan indigenous people which can be dated 5,000 years ago. The genetic diversity of Taiwan foxtail millet germplasm is very high due to various applications selected by different indigenous tribes. A total of 133 Taiwanese landraces of foxtail millet collected from Taiwan indigenous tribes were assessed by agronomic traits and grain starch physicochemical properties. These landraces are significantly different in plant height in the range of 54.7-124.7 cm with the mean of 93.7 cm, heading date in the range of 53.7-109.5 days with the mean of 75.2 days, panicle length in the range of 9.6-56.72 cm with the mean of 23.4 cm, panicle width in the range of 1.12-3.17 cm with the mean of 2.02 cm, and 1000-seed weight in the range of 0.96-2.85 g with the mean of 1.85 g. The major composition of polished grains is starch, approximate 75%. The apparent amylose content (AAC) of 117 analyzed accessions was ranged from 0.69 to 16.92%, which 63, 34, and 20 accessions were classified as waxy (＜5% AAC), low AC (5~10%), and non-waxy (＞10%), respectively. The geographical distribution of foxtail millet germplasm based on AAC was not evenly distributed along with the aboriginal tribes, suggesting has gene through artificial selection due to various preferences of foods and traditional cultures. In this study, the preliminary investigation of agronomic traits and AAC provide useful information for genome wide association study (GWAS) to unveil untapped Taiwan foxtail millet germplasm, which can be further applied to breeding programs focusing on improving eating and cooking quality by marker-assisted selection.

並列關鍵字

Foxtail millet ； Agronomic traits ； Apparent amylose content (AAC)

國際替代計量

初探臺灣小米種原之重要農藝性狀與米質

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