Russell B W, Mills D
Department of Botany and Plant Pathology, Oregon State University, Corvallis 97331-2902.
Mol Plant Microbe Interact. 1993 Jan-Feb;6(1):66-74. doi: 10.1094/mpmi-6-066.
Electrophoretic karyotypes were obtained from intact sporidia and mycelia of Tilletia controversa and T. caries, and hybrid progeny were obtained by crossing these pathogens. The chromosomes typically ranged from approximately 850 to 4,490 kilobases (kb) for all strains, and they were variable in number with 19 or 20 for strains of T. controversa, 14-20 for T. caries, and from 19 to 22 for the hybrid progeny. The estimated genome size varied from 28 to 42 megabases (Mb) for these strains. Radiolabeled probes made of single copy DNA fragments and a heterologous actin gene identified four linkage groups among all strains that exhibited maximum chromosome length polymorphisms of 14% or less. The chromosomes carrying the rDNA genes, representing a fifth linkage group, exhibited length polymorphisms of approximately 40%. The actin gene and a rDNA probe hybridized with one or more bands in these strains, suggesting that some of the variability in chromosome number may result from aneuploidy. The karyotypes of the hybrid progeny revealed chromosome numbers and genome sizes essentially identical to each parental strain, clearly indicating that the reduction division stage of meiosis had occurred. These data and other corroborative genetic data provide substantial evidence that T. controversa and T. caries are not different species, but variants of a single species.
从网腥黑粉菌和小麦光腥黑粉菌的完整担孢子和菌丝体中获得了电泳核型，并通过杂交这些病原菌获得了杂交后代。所有菌株的染色体长度通常在约850至4490千碱基（kb）之间，数量各不相同，网腥黑粉菌菌株有19或20条染色体，小麦光腥黑粉菌有14 - 20条，杂交后代有19至22条。这些菌株的估计基因组大小在28至42兆碱基（Mb）之间。由单拷贝DNA片段和异源肌动蛋白基因制成的放射性标记探针在所有菌株中鉴定出四个连锁群，这些连锁群表现出最大14%或更低的染色体长度多态性。携带rDNA基因的染色体代表第五个连锁群，表现出约40%的长度多态性。肌动蛋白基因和rDNA探针与这些菌株中的一条或多条带杂交，表明染色体数量的一些变异性可能是由非整倍性引起的。杂交后代的核型显示染色体数量和基因组大小与每个亲本菌株基本相同，清楚地表明减数分裂的减数分裂阶段已经发生。这些数据和其他确凿的遗传数据提供了大量证据，表明网腥黑粉菌和小麦光腥黑粉菌不是不同的物种，而是单一物种的变体。
