Determination method for onion

Provided is a means for determining, with high accuracy, whether or not an onion has a spicy taste and/or a lachrymatory property. The present invention relates to a method for determining the characteristics of an onion, the method being characterized by comprising: a first detection step for detecting a base sequence of SEQ ID NO: 1 corresponding to an alliinase gene 1 in a nucleic acid derivedfrom the onion; and a second detection step for detecting a base sequence of SEQ ID NO: 2 corresponding to an alliinase gene 2 in the nucleic acid derived from the onion, wherein, if the base sequenceof SEQ ID NO: 1 is not detected in the first detection step and the base sequence of SEQ ID NO: 2 is detected in the second detection step, it is determined that the onion is an onion that does not have a spicy taste and/or a lachrymatory property. 本发明提供一种用于高精度地判别洋葱是否为没有辛辣味和/或催泪性的洋葱的方案。本发明涉及一种洋葱的性状的判别方法，其特征在于，包括：第一检测工序，在来自洋葱的核酸中，检测与蒜氨酸酶基因1对应的序列号1的碱基序列；以及第二检测工序，检测与蒜氨酸酶基因2对应的序列号2的碱基序列，当在第一检测工序中未检测到序列号1的碱基序列且在第二检测工序中检测到序列号2的