Institute of Agronomy and Plant Breeding, University of Göttingen, von-Siebold-Straße 8, D-3400, Göttingen, Federal Republic of Germany.
Theor Appl Genet. 1984 Mar;67(5):457-61. doi: 10.1007/BF00263412.
In five genetically different inbred lines of rye and in the seven 'Chinese Spring'/'Imperial' wheatrye addition lines, chiasma distribution in rye chromosomes was studied with respect to the amount and position of constitutive heterochromatin (Giemsa C-bands). In all inbred lines, rye chromosomes with one primary terminal band were more frequently found as univalents than those with primary bands on both telomeres. These chromosomes were most probably 5R and/or 6R. In the addition lines a highly significant reduction in the number of arms bound by chiasmata was found for rye chromosomes 5R and 6R. Because of the similar chiasma distribution in the inbred lines and in the rye chromosomes of the addition lines, no effect of the wheat genome on the number of chiasmata in the rye chromosomes can be ascertained. However, a relationship between chiasma frequency and chromosome arm length seems to exist, since under reduced chiasma conditions the two shortest arms of the rye complement, those of chromosomes 5R and 6R, frequently fail to form a chiasma. No effect of the large blocks of constitutive heterochromatin in the telomeres of the rye chromosomes on the position of chiasmata within a bivalent could be established.
在五种遗传上不同的近交系黑麦和 7 个“中国春”/“帝王”小麦黑麦添加系中，研究了与组成型异染色质（吉姆萨 C-带）数量和位置有关的黑麦染色体的交叉分布。在所有近交系中，具有一个初级末端带的黑麦染色体比具有两个末端带的初级带的黑麦染色体更频繁地作为单价体出现。这些染色体很可能是 5R 和/或 6R。在添加系中，发现 5R 和 6R 黑麦染色体的着丝粒结合臂的数量显著减少。由于近交系和添加系黑麦染色体的交叉分布相似，因此不能确定小麦基因组对黑麦染色体交叉数的影响。然而，似乎存在着交叉频率和染色体臂长度之间的关系，因为在交叉减少的情况下，黑麦染色体的两个最短臂，即 5R 和 6R 的染色体臂，经常不能形成交叉。在黑麦染色体末端的大的组成型异染色质块对二价体内部的交叉位置没有影响。
