Establishing the Salmon method for wheat haploid production

一种普通小麦，具有鲑鱼小麦的1B-1R易位染色体和粗毛山羊草(Aegilopskotschyi)的S^v细胞质。变异体产生单倍体的频率很高。然而，当它们进行染色体加倍时，只获得了雄性不育植株，没有育种价值。在这个项目中，我们的目标是开发一种遗传系统，利用它，当染色体加倍时，我们可以获得产生雄性可育植株的单倍体。已经采取了以下两种方法：(1)诱导从PM到SS=的突变，以使抑制PTG基因的SPQ的功能失活，从而诱导单倍体。(2)对携带1B-LR易位的普通小麦品种进行Rfv1 spg基因的筛选。(1)诱变剂处理普通小麦中突变株ssm至spg的筛选--用0.2-0.6%的EMS处理普通小麦CS的预浸种子，其M_2代与具有S^v型细胞质…的鲑鱼异质系杂交更多(缩写(S^v)--三文鱼。在下一代中，观察单株的种子育性，并检测其后代的单倍体频率。共检测了715个M_2代品系，获得了一些单倍体频率较高的品系。遗憾的是，所有这些材料都表现出很低的育性，我们无法获得任何具有预期基因Rfv1 spg的突变株系。(2)对携带1B-LR易位的小麦品种进行Rfv1 SPQ基因的筛选-共有26个品种以父本为父本与(S^v)-CS杂交，F1代以这些品种为母本回交。在B_1代，每株系的结实率约为15株，其后代的单倍体频率也很高。几乎所有品种都产生了没有单倍体的高育性或单倍体频率高的低育性的毕氏后代。唯一例外的是CIMMYT选育的一个品系XXXXXX，该品系具有高育性和高单倍体频率。我们假设这一特定品系具有我们一直在寻找的Rfvl spg基因。注)CIMMYT品系的名称不会公布。较少

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