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本文研究了原产澳大利亚的稀毛棉（Ｇ．ｐｉｌｏｓｕｍ）、皱壳棉（Ｇ．ｃｏｓｔｕｌａｔｕｍ）、杨叶棉（Ｇ．ｐｏｐｕｌｉｆｏｌｉｕｍ）的核型。稀毛棉的核型公式为２ｎ＝２ｘ＝２６＝１６ｍ（４ｓａｔ）＋１０ｓｍ，皱壳棉为２ｎ＝２ｘ＝２６＝１６ｍ（４ｓａｔ）＋１０ｓｍ，杨叶棉为２ｎ＝２ｘ＝２６＝１８ｍ（４ｓａｔ）＋８ｓｍ。随体均有两对，一对位于第１１对染色体的长臂上，另一对位于第１３对染色体的短臂上。平均臂比和长度比分别为稀毛棉１．５３和２．５１、皱壳棉１．５５和２．３１、杨叶棉１．４９和２．３７，其核型均属于Ｓｔｅｂｂｉｎｓ的２Ｂ类型。对称系数稀毛棉为２６．０４，皱壳棉为２７．９３，杨叶棉为２８．３２。三者彼此之间的核型重合率均在９０％以上。核型的同质性说明三者在起源上有很好的一致性
In this paper, the karyotypes of native G.pilosum, G.ostulatum and G.populifolium from Australia were studied. The karyotype formula of thinning cotton is 2n = 2x = 26 = 16m (4sat) + 10sm, the wrinkle cotton is 2n = 2x = 26 = 16m (4sat) + 8sm. There are two pairs of satellites, one pair is located on the long arm of chromosome 11 and the other pair is located on the short arm of chromosome 13. The average arm ratio and length ratio were 1.53 and 2.51 for sparse cotton, 1.55 and 2.31 for wrinkled cotton and 1.49 and 2.37 for poplar cotton, all of which belonged to type 2B of Stebbins . Symmetry coefficient of thin cotton is 26.04, wrinkled cotton is 27.93, Young leaves cotton is 28.32. The three nuclear karyotype coincidence rate of more than 90%. The homogeneity of karyotype shows that the three have a good consistency in origin