小麦族下Hystrix longearistata和Hystrix duthiei的生物系统学研究

Biosystematic studies on Hystrix longearistata from Japan and Hystrix duthiei from China (Poaceae: Triticeae)

对Ｈｙｓｔｒｉｘｄｕｔｈｉｅｉ、Ｈ．ｌｏｎｇｅａｒｉｓｔａｔａ和它们的人工种间杂种花粉母细胞减数分裂染色体配对行为、繁育特征和形态特征进行了比较分析，结果表明：（１）这两个分类单位形态差异较小，Ｈ．ｌｏｎｇｅａｒｉｓｔａｔａ的外稃芒较长，叶片较宽，每小穗具２～３个小花；Ｈ．ｄｕｔｈｉｅｉ的外稃芒较短，叶片较窄，每小穗具１～２个小花。（２）它们很容易杂交，杂种Ｆ１染色体配对频率很高，为１３～１４个二价体。（３）亲本种花粉育性和结实性正常，杂种Ｆ１花粉育性较低，结实性较差。（４）Ｈ．ｌｏｎｇｅａｒｉｓｔａｔａ和Ｈ．ｄｕｔｈｉｅｉ亲缘关系很近，是同一物种。由于地理分布和生境的差异，使它们在形态上开始分异，并出现一定程度的生殖隔离。把Ｈ．ｌｏｎｇｅａｒｉｓｔａｔａ处理为Ｈｙｓｔｒｉｘｄｕｔｈｉｅｉ的一亚种是合理的。

Morphological comparison, cytogenetic study and fertility analysis of Hystrix duthiei (2n=28) from China, Hystrix longearistata (2n=28) from Japan and their artificial hybrids were carried out. Morphologically H. duthiei was similar to H. longearistata. H. longearistata had longer lemma awn,wider leaf and 2～3 florets per spikelet, while H. duthiei had 1～2 florets per spikelet. These two taxa can be easily crossed. F 1 hybrids showed very high degree of bivalent pairing (13～14 bivalents) at the metaphase Ⅰ of meiosis. No multivalents were found. The fertility of pollen and seed set of the parents were normal, while the F 1 hybrids were of only partial fertility. H. longearistata was closely related to H. duthiei. They should be included in the same species. Because of the differences of their distributions and habitats, some morphological divergency and a little sterility barrier have had appeared between them. It is reasonable to treat Hystrix longearistata as a subspecies of Hystrix duthiei.