A cytogenetic study in the Acanthaceae
A cytogenetic study in the Acanthaceae
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棘科植物的细胞遗传学研究
作者：
W. Grant
兰科植物是双子叶植物的第九大科，包括200多个属和2000多个种（Willis 1948，1949）。此外，它们形成了第三大的Ixopical科，在大小上仅超过桃金娘科（Myrtaceae）和白千层科（Mackinataceae）（Good 1947）。虽然该科多年来一直被认为是一个独特的分类群，但该科的分类主要基于花粉雕刻和花药的次要特征（Lindau 1895; Bremekamp 1943）。在这样的分类中，物种有时是如此相似，以至于很难将它们归为单独的属（或族，Bremekamp 1948），它们的真实关系有时是可疑的。许多贡献已作出的形态学，解剖学和分布的家庭，但它很少得到细胞学的关注。这可能是因为它主要是热带和物种相对难以接近。对全科的现有材料进行了细胞学研究，以探讨属间关系，并为进一步研究特定分类群奠定基础。通过对该科的细胞学研究，已经确定了一些属间和属内关系的密切亲缘关系（Narayanan 1951 a）。该科是泛热带的，有四个主要的分布中心：印度-马来亚，非洲，巴西和中美洲。在欧洲，它仅以到达地中海的Acanthus属的少数物种为代表。大约有12个属遍布热带地区。其中包括该科最大的两个属：lusticia和Ruellia，分别有325和225种。在其余的属中，约20%主要局限于亚洲，38%局限于非洲，42%局限于美洲。亚热带物种分布于澳大利亚、南非、中国、日本和美国。至少有21属表现出不连续的分布; 19种在非洲和亚洲（威利斯1949年，'页。1988 -216; Good 1947，pp. 356-3587，一个（Schaueria）在美洲和非洲（好1.c.），美洲和亚洲各有1个（Staurogyne）（Willis 1.c.）。约有120个属是单型的，分布范围有限。在相对较少的延伸到美国的属和种中，有三个出现在东北部（Justicia，Ruellia，Dyschoriste），这些和其他六个出现在东南部（Thunbergia，ltygrophila，Elytraria，Stenopulum，Dieliptera和Yeatsia）。一些其他属的物种原产于西南部各州（劳伦斯1951）。大多数植物学家认为玄参科是从玄参科或其祖先的种群中衍生出来的。Bessey（1915）将该科归入玄参目（Scrophulariales），Engler和Diels（1936）归入管花目（Tubiflorae），Bentham和Hooker（1876）和哈钦森（1948）归入个人目（Personales）。Engler和Diels将紫珠科置于Globulariaceae和Myoporaceae两个小科之间，但它们更接近更大更复杂的Gesneri科。
The Acanthaceae are the ninth largest family of dicotyledonous plants, including over 200 genera and 2000 species (Willis 1948, 1949). In addition, they form the third largest Ixopical family, exceeded in size only by the Myrtaceae and Melastomataceae (Good 1947). Although the Acanthaceae have for many years been considered as a distinct taxon, the classification of the family has been based largely on pollen-sculpture and minor characters of the anthers (Lindau 1895; Bremekamp 1943). In such a classification the species are sometimes so much alike that it is difficult to group them into separate genera (or tribes, Bremekamp 1948) and their true relationships are sometimes doubtful. Many contributions have been made to the morphology, anatomy, and distribution of the family, but it has received little cytological attention. This is probably because it is largely tropical and the species are relatively inaccessible. A cytological study of the available material of the whole family was made to investigate generic relationships and to lay a foundation for further investigation of specific taxa. The close affinity of some interand intrageneric relationships has been determined through cytological studies on the family (Narayanan 1951a). The family is pantropical, with four chief centers of distribution: Indo-Malaya, Africa, Brazil, and Central America. In Europe it is represented by only a few species of the genus Acanthus, which reach the Mediterranean. About 12 genera are cosmopolitan throughout the tropics. These include the two largest genera of the family: lusticia and Ruellia, with 325 and 225 species respectively. Of the remaining genera about 20 per cent are largely confined to Asia, 38 per cent to Africa, and 42 per cent to America. Subtropical species are found in Australia, South Africa, China, Japan, and the United States. At least 21 genera exhibit discontinuous distribution; 19 have species in Africa and Asia (Willis 1949,'pp. 198-216; Good 1947, pp. 356-3587, one (Schaueria) in America and Africa (Good 1.c.), and one (Staurogyne) in America and Asia (Willis 1.c.). Approximately 120 genera are monotypic and restricted in range. Of the relatively few genera and species which extend into the United States, three occur in the northeast (Justicia, Ruellia, Dyschoriste), and these and six others occur in the southeast (Thunbergia, ltygrophila, Elytraria, Stenandrium, Dieliptera, and Yeatsia). A number of additional genera have species indigenous to the southwestern states (Lawrence 1951). The Acanthaceae are considered by most botanists to have been derived from the Scrophulariaceae or stocks ancestral to them. Bessey (1915) placed the family in the order Scrophulariales, Engler and Diels (1936) in the order Tubiflorae, and Bentham and Hooker (1876) and Hutchinson (1948) in the order Personales. Engler and Diels placed the Acanthaceae between the small families Globulariaceae and Myoporaceae, but they are nearer the larger and more complex family Gesneri-