Production of gene map using chromosome deletions in common wheat

本研究的主要目的是在普通小麦品种中国春中建立一系列的缺失砧木，1990 - 1991年的研究基本完成了这一目的。通过C-分带的细胞学选择，在几个自花授粉世代中，共鉴定并分离出382条缺失染色体。其中263个为结构纯合型，存在一对临界缺失，无相应的正常同源物。这些缺失储备物可以按原样用于缺失作图。然而，对于剩余的缺失，既没有获得纯合植物，也没有获得能育的植物。因此，大多数杂合缺失群体，其中有一个关键缺失和一个相应的正常同源物，与中国春缺体-四体群体，其中缺乏一桶染色体，有两对同源染色体。从这些F1中，可以选择其中存在一个关键缺失而没有相应同源物的半合子植物用于缺失作图。由于缺乏合适的缺体四体，2A染色体和4 B染色体短臂的缺失一直保持在杂合状态，纯合体不育，利用已产生的缺失原种，对雄性育性基因和育性恢复基因进行了对异源细胞质的缺失定位，结果已发表或即将发表。其他有关同工酶基因和DNA标记的缺失图谱正在进行中。

The main purpose of this research was to produce a series of deletion stocks in a common wheat cultivar Chinese Spring, and it was mostly fulfilled by the study conducted from 1990 to 1991. A total of 382 deletion chromosomes were identified and isolated through the cytological selection by C-banding during several self-pollinated generations. 263 of them were in structually homozyhgous condition, in which there are a pair of a critical deletion and no corresponding normal homologue. These deletion stocks can be used for deletion mapping as they are. For the remaining deletions, however, homozygous plants were neither obtained nor fertile. Therefore, most of these heterozygous deletion stocks, in which there are one critical deletion and one corresponding normal homologue, were crossed with Chinese Spring nullisomic-tetrasomic stocks, which lack a pail, of chromosomes and have two pairs of a homoeologous chromosomes. From these Fl's, hemizygous plants, in which there is one critical deletion and no corresponding homologue, can be selected for deletion mapping. The deletions in the short arms of chromosome 2A and chromosoem 4B, whose homozygotes were sterile, have been maintained in heterozygou condition because no appropriate nullisomic-tetrasomics are available.Using the deletion stocks so far produced, deletion mappings with male-fertility gene and fertility-restoring gene against alien cytoplasm were conducted and the results wei, e published, or will be published soon. Other deletion mapping concerning some isozyrne genes and DNA markers are in progress.