A CYTOLOGICAL STUDY IN THE GRAMINEAE
A CYTOLOGICAL STUDY IN THE GRAMINEAE
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DOI：
10.1002/j.1537-2197.1948.tb08097.x
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发表时间：
1948-07
影响因子：
3
通讯作者：
W. Brown
中科院分区：
文献类型：
--
作者：
W. Brown
许多细胞学研究（Stiihlin, 1929; Avdulow, 1931; Armstrong, 1937; Flovik, 1938； Stebbins和Love， 1941）都是用原产于欧洲、北美和亚洲地区，特别是温带地区的草进行的。因此，在温带的部落中，已知几十个属的数百种的染色体数目，如在细胞学上研究过的Aveneae有16个属，hordae有12个属，agrostidae有27个属，Festuceae有32个属。与这些温带部落相反的是热带和暖温带的Paniceae，这是草科中最大的部落之一。在这个有60余属1400余种的科中，仅有11属72种的生态学研究。本文主要是关于美国东南部panicae的细胞学研究。此外，还研究了Oryzeae、Zizaneae和Hordeae部落中某些属的若干种。我们特别努力在尽可能多的分类区段中研究了尽可能多的种，特别是在双anthelium亚属中。这个亚属是一个由大约80种密切相关的物种组成的群，形成了一个非常均匀和分类困难的群，在美国东南部物种最集中。本研究试图从细胞学上的证据来确定禾本科的种、属和部落之间的某些相互关系。由于所研究的物种和变种数量众多，共计115种，故将结果描述和分组讨论结合起来。在草属和草属中，许多与讨论有关的物种在结果描述中没有提到，但它们都列在表1中。材料和方法。-所有被研究的panicae植物均收集于美国东南部，除了来自科罗拉多州的Panicum obtusum。尽可能在田间收集根尖，或盆栽，在温室生长一段时间后收集根尖。同样的收集方法也适用于在美国东部从新罕布什尔州到北卡罗莱纳州收集的加拿大羊草、维延地羊草、维延地羊草、帕特拉羊蹄草、紫茎草和卡罗来纳水藻。所有其他种类的羊草和西塔尼乌斯都是由美国农业部土壤保持局提供的种子培育而成的。所有的根茎提示都在Navashin的1 Received发表于1948年2月2日。作者希望对Lewis E. Anderson博士在整个研究过程中所给予的激励性指导表示深深的感谢。衷心感谢有帮助的批评和建议，也延伸到(e) L.丘奇博士和卡尔·萨克斯博士。固定液包埋石蜡，碘结晶紫法切片染色。在田间收集水藻（Zizania aquatica）、水藻（Zizaniopsis milicea）和三种Leersia的减数分裂研究材料，在绝对乙酸（70%无水乙醇和30%冰醋酸）中固定，然后涂上醋酸胭脂红。在可能的情况下，原始收藏被作为植物标本室标本保存下来，这些标本存放在德克萨斯大学的植物标本室。所有的panicae都是由杜克大学的H. L. Blomquist博士验证或确定的。希区柯克（1935）的命名法在整部作品中都有使用，除了：Elymus Wiegandii Fernald (1933)；《世界恐慌》（1936）；Panicum bennettense Brown（1942）。图纸以不同的放大倍率绘制，并以1850倍的倍率复制了Paniceae，以1360倍的倍率复制了所有其他的。结果描述。-获得的染色体数目如表1所示。除了从美国农业部提供的种子中获得的植物外，作者的细胞学检查收集的收集编号也被列出，在这种情况下，使用他们的加入编号。在许多情况下，根尖是从多个植物收集到的，这些植物在特定物种的收集编号下列出。在少数情况下，在一个群体中从几个形态上难以区分的植物中获得根尖，然而，不幸的是，只有一株植物从这个群体中被保留下来作为植物标本室标本。这就解释了在相同的马地黄根尖和金合欢根尖上报道的多于一个染色体数目。列出的2n个数字表明检查了根尖；研究减数分裂的n个数。在引用先前记录的数目时，只列出一个参考文献，通常是该物种染色体数目的第一次报告。如果一个物种报告了一个以上的编号，则可以列出两个或两个以上的参考文献。以前报道的物种的染色体数目不列出，除非作者研究的是同一物种。一个例外是在Panicurn亚属Dicanthelium的情况下，其中列出了迄今为止报道的所有物种。Hordeae。-从细胞学上讲，榆草属是Hordeae部落的典型，具有较大的染色体，具有广泛的多倍体，包括许多细胞遗传菌株，并且根据Stebbins等人（1946）的说法，具有相当大的属间杂交。在调查的15个种和变种中，14个是多倍体。原产于苏联Kasakstan地区的E. junceus，有2n - 14条染色体，是唯一发现的二倍体种。这是本属报道的第二个二倍体种。根据
NUMEROUS CYTOLOGICAL studies (Stiihlin, 1929; Avdulow, 1931; Armstrong, 1937; Flovik, 1938; Stebbins and Love, 1941) have been made of grasses native to regions of Europe, North America, and Asia, especially those of temperate zones. As a result the chromosome numbers of many hundreds of species in dozens of genera are known in such temperate zone tribes as Aveneae with sixteen genera studied cytologically, Hordeae, twelve genera, Agrostideae, twenty-seven genera, and Festuceae, thirty-two genera. In contrast to these temperate zone tribes is the tropical and warm temperate Paniceae, one of the largest tribes in the grass family. In this tribe of over 60 genera and 1400 species only 72 species in 11 genera have been studied cvtologically. The present paper is primarily concerned with a cytological study of the Paniceae of the southeastern United States. In addition, a number of species in certain genera of the tribes Oryzeae, Zizaneae and Hordeae were studied. A special effort was made to study as many species in as many taxonomic sections of the genus Panicum as possible, especially in the subgenus Dicanthelium. This subgenus is a group of some eighty closely related species forming a very homogeneous and taxonomically difficult group with the greatest concentration of species in the southeastern United States. The present study was made in an attempt to determine certain interrelationships of species, genera and tribes of the family Gramineae from evidence offered by cytology. Because of the large number of species and varieties studied, these totalling 115, the description of results and discussion of groups are combined. In the genera Elymus and Panicum many species pertinent to the discussion are not mentioned in the description of results but they are all listed in table 1. MATERIALS AND METHODS.-All plants studied in the Paniceae were collected in the southeastern United States except Panicum obtusum from Colorado. Root tips were collected in the field when possible or the plants were potted and tips collected after a period of growth in the greenhouse. The same collecting method applies to Elymus canadensis, E. Wieyandii, E. virginicus, Hystrix patula, Zizaniopsis miliacea and Hydrochloa carolinensis which were collected in the eastern United States from New Hampshire to North Carolina. All other species of Elymus as well as Sitanion hystrix were grown from seed furnished by the U. S. Dept. of Agriculture, Soil Conservation Service. All root tips were fixed in Navashin's 1 Received for publication February 2, 1948. The writer wishes to express his deep appreciation of the stimulating guidance received from Dr. Lewis E. Anderson throughout the course of this research. Sincere thanks for helpful criticism and advice are also extended to Dr. (eor(e L. Church and Dr. Karl Sax. fixative, embedded in paraffin, sectioned and stained with the iodine-crystal-violet method. Material for the meiotic studies of Zizania aquatica, Zizaniopsis milicea and the three species of Leersia was collected in the field, fixed in absolute-acetic (70 per cent absolute ethyl alcohol and 30 per cent glacial acetic acid), and smeared in aceto-carmine. When possible, the original collections were retained as herbarium specimens and these are deposited in the University of Texas herbarium. All Paniceae were verified or determined by Dr. H. L. Blomquist of Duke University. The nomenclature of Hitchcock (1935) is used throughout this work except for: Elymus Wiegandii Fernald (1933); Panicum mundum Fernald (1936); and Panicum bennettense Brown (1942). Drawings were made at various magnifications and reproduced at 1,850 X for Paniceae and 1,360 X for all others. DESCRIPTION OF RESULTS.-Table 1 lists the chromosome numbers obtained. The author's collection numbers of the collections examined cytologically are also listed except for plants obtained from seed furnished by the U. S. Dept. of Agriculture in which case their accession numbers are used. In many cases root tips were collected from more than the one plant listed under the collection number for the particular species. In a few cases root tips were obtained from several morphologicallv indistinguishable plants in a single colony, yet, unfortunately, only a single plant from the colony was retained for an herbarium specimen. This accounts for more than one chromosome number being reported for the same collection of root tips of Digitaria sanguinalis and of Panicum virgatum. The listing of 2n numbers indicates that root tips were examined; that of the n number that meiosis was studied. In citing references for previously recorded numbers, one reference only, usually the first report of the chromosome number for the species, is listed. In cases where more than one number has been reported for a species, two or more references may be listed. Chromosome numbers of species previously reported are not listed unless the same species was studied by the author. An exception is made in the case of Panicurn subgenus Dicanthelium in which all species so far reported are listed. Hordeae.-The genus Elymus is cytologically typical of the tribe Hordeae with its large chromosomes, with a wide range of polyploidy including numerous cytogenetic strains and, according to Stebbins et al. (1946), with considerable intergeneric hybridization. Of the fifteen species and varieties investigated fourteen are polyploid. E. junceus, 2n 14 chromosomes, a species native to the Kasakstan region of the U. S. S. R., is the only diploid species found. This is the second diploid species reported in this genus. According