Use of a self-compatible diploid potato for mutagenesis and forward genetic studies.

许多植物的遗传学研究都得益于自然或人工诱导的突变体的使用，在这些突变体中，一个或多个基因的功能已经丢失或改变。诱变可以通过使用诱变化学品或其他手段(例如电离辐射)来实现，当然，所有自然发生的遗传都是由于长时间发生的突变。孟德尔著名的豌豆实验利用了自然产生的突变体，这些突变体在高度可视化的单基因特征上与野生类型不同。许多作物品种本身就是突变体。大麦品种Golden Promise是老品种Maythorpe的突变体。可以对突变进行基因图谱绘制，可以使用各种方法来识别突变基因，提供有用的信息，这些信息可以应用于进一步的研究和植物育种。农作物马铃薯自然是异源繁殖的四倍体，这使得产生在其他农作物中非常有用的那种突变变异变得极其困难。这是因为土豆的每个基因都有四个拷贝，而要培育出任何一个基因的所有四个拷贝都有突变版本的植物几乎是不可能的。同样的情况在二倍体土豆中也是如此，因为二倍体土豆的每个基因只有两个拷贝(二倍体)。由于这一原因和其他原因，马铃薯的遗传研究一直落后于其他植物，遗传分析不得不依赖自然发生的变异，其中大多数表现为连续或非离散的变异。在这个项目中，我们计划通过利用一种土豆(Solanum Verrucosum)来解决这个问题，这种土豆既是二倍体的，又是天然的近亲繁殖者，允许构建“纯合”的基因类型，其中每个基因的两个副本都是相同的。在中试实验中，我们已经证明，利用疣状链霉菌产生突变植株群体是可行的，这些突变植株群体可以极大地促进遗传研究，这将对马铃薯的下游改良产生影响。突变小组将评估与马铃薯育种相关的性状变异：块茎特征、植物结构特征、块茎发芽等，并将选出约100个有趣的突变小组进行进一步研究。在试点实验中，已经确定了几个有趣的突变，这些突变将在这个项目中进行研究。其中一些突变体，包括一个具有明显“矮化”表型的突变体，将被用来测试一种分离突变基因的新方法。这还需要产生用于突变的基因的基因组草稿序列。矮秆突变体还将接受育性测试，以确定在未来的诱变研究中是否可行。该项目的结果将是：(1)建立有史以来第一个马铃薯突变体库。(2)普通茄子‘碱基基因型’基因组草图序列的阐明。(3)对已鉴定的一个或多个突变体进行候选基因和突变等位基因的鉴定。

Studies of the genetics of many plants have benefited greatly from the use of mutants, either spontaneous or artificially induced, in which the function of one or more genes has been lost or modified. Mutagenesis can be achieved by use of mutagenic chemicals or other means (e.g. ionizing radiation), and of course all naturally occurring genetic is due to mutation occurring over long time periods. Mendel's famous experiments with peas utilized naturally occurring mutants differing from the 'wild type' in highly visual, single gene traits. Many crop varieties are themselves mutants. The barley variety Golden Promise is a mutant of an older variety Maythorpe. Mutations can be genetically mapped and various approaches can be used to identify the mutated gene, providing useful information, which can be applied to further research and to plant breeding. The crop plant potato is naturally an outbreeding tetraploid, which makes it extremely difficult to generate the sort of mutational variation that has been so useful in other crop plants. This is because potato has four copies of each gene, and to generate a plant that has a mutated version of all four copies of any one gene is virtually impossible. The same is true to a lesser extent in diploid potatoes which have only two copies of each gene (diploids). For this and other reasons genetic studies in potato have lagged behind other plants, and genetic analysis has had to rely on naturally occurring variation, most of which is manifest as continuous or 'non-discrete' variation. In this project we plan to address this by utilizing a species of potato (Solanum verrucosum) that is both diploid and which is a natural inbreeder, allowing the construction of 'homozygous' genotypes, where both copies of each gene are identical. In pilot experiments we have shown that, using S. verrucosum, it is feasible to generate populations of mutant plants that can greatly benefit genetic studies, which will have downstream impact on potato improvement. The mutant panel will be assessed for variation in traits relevant to potato breeding: tuber characteristics, plant architecture traits, tuber sprouting etc and a panel of ~100 interesting mutants will be selected for further study. In pilot experiments a few interesting mutants have been identified and these will be studied within this project. Some of these mutants including one having a clear 'dwarfing' phenotype will used to test a novel approach for isolating the gene that has been mutated. This will also entail generating a draft genome sequence of the genotype used for the mutagenesis. The dwarf mutant will also be tested for its fertility to see whether it is feasible to use this in future mutagenesis studies.The outcomes of this project will be (1) The establishment of the first ever mutant collection of potato. (2) The elucidation of a draft genome sequence of the 'base genotype' of Solanum verrucosum. (3) The identification of candidate genes and mutated alleles for one or more of the mutants identified.