Establishing the Salmon method for wheat haploid production

一种普通小麦，具有鲑鱼小麦的1B-1 R易位染色体和山羊草或山羊草的S^v细胞质。variabilis以高频率产生单倍体。然而，当它们被染色体加倍时，仅获得没有育种价值的麦芽糖植物。本项目旨在建立一个染色体加倍的遗传系统，使染色体加倍后的植株产生单倍体。采用了以下两种方法：（1）诱导PM突变为SS，以消除Spq抑制Ptg基因诱导单倍体的功能。(2)在染色体上携带1B-IR易位的普通小麦品种中筛选Rfvl spg基因型。结果如下：（1）诱变处理小麦中SSM突变体的筛选--用0.2- 0.6%EMS处理普通小麦CS的预浸种子，其M_2代与S_（v）型Salmon异源细胞质系杂交 关于我们 （焦v.（S^v）-Salmon）.在下一代中，观察个体植物的种子育性，并测试其后代中的单倍体频率。共检测了715个M_2代株系，获得了一些高单倍体频率的株系。不幸的是，所有这些品系都显示出非常低的育性，并且我们不能得到具有预期基因型Rfvl spg的任何突变品系。(2)1B-1 R易位系小麦品种中Rfvl spq基因型的筛选--以26个小麦品种为父本与（S_（v））-CS杂交，F_1代以这些品种为母本回交。在B1代中，观察到每系约15株植物的种子育性和其后代中的单倍体频率。几乎所有的品种都产生了高育性而无单倍体或低育性而高单倍体频率的Bi后代。唯一的例外是CIMMYT培育的XXXXL系，其产生具有高育性和高单倍体频率的B1系。我们假设这一特定品系具有我们一直在寻找的基因型Rfvl spg。注）CIMMYT品系的名称将不会公布。少

A common wheat having the 1B-1R translocation chromosome of Salmon wheat and an S^v cytoplasm of Aegilops kotschyi or Ae. variabilis produces haploids at a high frequency. However, when they are chromosome-doubled, only malesterile plants are obtained, which have no breeding value. In this project we aimed to develop a genetic system with which we can get haploids producing male-fertile plants when chromosome-doubled. The following two approaches have been undertaken : (1) Induction of a mutation from PM to SS= to inactivate the function of Spq suppressing the Ptg gene for haploid induction. (2) Screening of the Rfvl spg genotype among common wheat cultivars carrying a 1B-lR translocation@hromosome. The results obtained are as follows :(1) Screening of the mutation, SSM to spg, among mutagen-treated common wheat --- Presoaked seeds of a common wheat CS were treated with 0.2-0.6% EMS, and their M_2 offspring were crossed as male to alloplasmic lines of Salmon with an S^v type cytoplasm … More (abbrev. (S^v)-Salmon). In the next generation seed fertility of the individual plants were observed and haploid frequency in their offspring was tested. In total, 715 M_2 lines were tested, and some lines showing high haploid frequency were obtained. Unfortunately, all these lines showed very low fertility, and we could not get any mutant line having the expected genotype, Rfvl spg.(2) Screening the Rfvl spq genotype among wheat cultivars carrying a 1B-lR translocation --- In total 26 cultivars were crossed as male to (S^v)-CS, and Fl hybrids were backcrossed to those cultivars as female parent. In the Bl generation seed fertility of about 15 plants per line and haploid frequency in their offspring were observed. Almost all cultivars produced the Bi offspring of high fertility with no haploids or low fertility with high haploid frequency. Only exception was a line XXXXXX bred by CIMMYT, that gave the Bl line with high fertility and high haploid frequency. We assume this particular line has the genotype, Rfvl spg, that we have been looking for.Note) The name of the CIMMYT line will not be publicized. Less