ISOZYMIC EVIDENCE BEARING ON THE ORIGIN OF NICOTIANA TABACUM L.
ISOZYMIC EVIDENCE BEARING ON THE ORIGIN OF NICOTIANA TABACUM L.
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关于烟草起源的同工证据。
DOI：
10.1111/j.1558-5646.1972.tb00181.x
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发表时间：
1972
期刊：
影响因子：
3.3
通讯作者：
S. J. Sheen
中科院分区：
文献类型：
--
作者：
S. J. Sheen
植物器官和组织的同工酶模式是特定基因在特定生长和分化阶段运作的直接反映。基因-酶系统在进化过程中影响生存和适应，因此可以为系统发育关系的研究提供有用的信息。最近的文献报道了同工酶模式在植物生物系统学中的应用（West和Garber, 1967; Sheen, 1970）。烟叶属已成为高等植物遗传和进化研究的有利材料。目前已知的有64种（Smith, 1968），其中异源多倍体N. tabacum是世界上唯一栽培的品种。从形态学、生态学、遗传学和细胞遗传学的研究中推断了烟草的起源和进化。一般认为，种间杂交以及随后的两倍性和基因重组在其进化过程中发挥了重要作用。然而，烟草N. tabacum在自然界中没有发现（Goodspeed, 1954），特别是在假定的祖先物种分布重叠的地理区域。因此，烟草的起源多年来一直是一个有争议的话题。1928年Clausen提出，N = 24的烟叶N. tabacum起源于N. sylvestris （N = 12）和N. tomentosa （N = 12）染色体加倍后的种间杂交。这一假设后来在关于毛毛科的祖先种方面被改变了。关于烟草的起源，目前有两种公认的假说。假设1由Clausen（1932）和Kostoff（1938）提出，他们认为N. tomentosiformis （N = 12）是祖先之一。相比之下，Goodspeed（1954）认为N. otophora (N = 12)（假设II）是现代烟草的近亲。两种假说都一致认为N. sylvestris的一个祖先是另一个祖先。最近，Cameron（1965）增加了证据，证明N. sylvestris为烟草N. tabacum的进化提供了细胞质。如果能通过实验杂交和两倍性合成该物种，将有助于阐明该物种的进化过程。Kostoff（1938）通过将N. sylvestris与N. tomentosiformis （2N = 24）的F1杂交体先回交给N. sylvestris，然后再回交给N. tomentosiformis来重建各自的基因组，进行了这样的实验。他获得了两个双二倍体（2N = 48），它们在分类上与烟草无法区分，并且很容易与烟草品种杂交。然而，两二倍体的某些形态特征与烟叶稻与绒毛稻的杂交后代相似。Greenleaf（1942）从F1杂交种的愈伤组织中获得了类似的两二倍体。与Kostoff双二倍体的自育性不同，愈伤组织诱导的双二倍体是完全雌性不育的，但具有高度的雄性可育性。秋水仙碱处理产生的两性二倍体表现出相同的雌性不育特征(D. U. Gerstel, pers。通讯)。本研究由肯塔基州列克星敦市肯塔基大学农学系提供。经署长批准，以第1号文件公布。（703-161）期刊系列，肯塔基农业实验站。
Isozyme patterns of plant organs and tissues are a direct reflection of particular genes that are operating at a given stage of growth and differentiation. Gene-enzyme systems affect survival and fitness in the course of evolution and consequently may provide useful information for studies of phylogenetic relationship. The application of isozyme patterns for biosystematics in plants has been reported in the recent literature (West and Garber, 1967; Sheen, 1970). The genus Nicotiana has been a favored material for studies on inheritance and evolution in higher plants. It comprises 64 presently recognized species (Smith, 1968), among which N. tabacum, an allopolyploid, is the only species cultivated around the world. The origin and evolution of N. tabacum has been deduced from morphological, ecological, genetic, and cytogenetic investigations. It is generally believed that interspecific hybridization, with subsequent amphiploidy as well as gene recombination, has played an important role in its evolution. However, N. tabacum is not found in nature (Goodspeed, 1954), particularly in the geographic area where the putative progenitor species overlap in their distribution. The origin of N. tabacum has, therefore, been a debatable subject for many years. In 1928 Clausen hypothesized that N. tabacum (N = 24) had originated from an interspecific hybrid between N. sylvestris (N = 12) and N. tomentosa (N = 12) after chromosome doubling. This hypothesis was later changed with regard to the progenitor species from the Tomentosae section. There are two currently recognized hypotheses regarding the origin of tobacco. Hypothesis I was proposed by Clausen (1932) and Kostoff (1938) who believed that N. tomentosiformis (N = 12) was one of the progenitors. In contrast, Goodspeed (1954) favored N. otophora (N = 12) (hypothesis II) as the closer relative of modern tobacco. Both hypotheses agreed that an ancestor of N. sylvestris was the other progenitor. Recently, Cameron (1965) added evidence that N. sylvestris contributed cytoplasm to the hybrid from which N. tabacum was evolved. The evolutionary process of N. tabacum may be clarified if synthesis of this species can be achieved through experimental hybridization and amphiploidy. Kostoff (1938) has conducted such experiments by backcrossing the F1 hybrid of N. sylvestris X N. tomentosiformis (2N = 24) first to N. sylvestris and then to N. tomentosiformis to reconstitute the respective genomes. He obtained two amphidiploids (2N = 48) which were taxonomically indistinguishable from N. tabacum and readily crossable with tobacco cultivars. However, some morphological features of the amphidiploids resembled the hybrids of a N. tabacum x (N. sylvestris x N. tomentosiformis) cross. Greenleaf (1942) produced similar amphidiploid from callus of the F1 hybrid. In contrast to Kostoff's amphidiploid which was self-fertile, the callus-induced one was completely female sterile but highly male fertile. Amphidiploids produced by colchicine treatments showed the same character of female sterility (D. U. Gerstel, pers. comm.). The present investigation was designed 1 Contribution from the Department of Agronomy, University of Kentucky, Lexington, Kentucky. Published with the approval of the Director as Paper No. (70-3-161) Journal series, Kentucky Agricultural Experiment Station.