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

许多植物的遗传学研究从突变体的使用中受益匪浅，无论是自发的还是人工诱导的，其中一个或多个基因的功能已经丢失或被修改。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与“野生型”不同的自然突变体，这些突变体具有高度视觉性和单基因特征。许多作物品种本身就是突变体。大麦品种黄金承诺是一个突变的老品种梅索普。突变可以被绘制成遗传图谱，并且可以使用各种方法来识别突变基因，为进一步的研究和植物育种提供有用的信息。马铃薯是一种天然的近亲繁殖的四倍体作物，这使得它很难产生在其他作物中非常有用的那种突变变异。这是因为土豆每个基因都有四个拷贝，而要培育出一种具有任何一个基因的所有四个拷贝的突变版本的植物几乎是不可能的。在二倍体土豆中，每个基因只有两个拷贝（二倍体），这种情况在较小程度上也是如此。由于这个和其他原因，马铃薯的遗传研究落后于其他植物，遗传分析不得不依赖于自然发生的变异，其中大多数表现为连续或“非离散”变异。在这个项目中，我们计划利用一种马铃薯（Solanum verrucosum）来解决这个问题，它既是二倍体又是天然近交系，允许构建“纯合”基因型，其中每个基因的两个拷贝都是相同的。在中试试验中，我们已经证明，利用疣状葡萄产生突变植株群体是可行的，这将极大地有利于遗传研究，这将对马铃薯改良产生下游影响。该突变体组将评估与马铃薯育种相关的性状变异：块茎特性、植株结构性状、块茎发芽等，并将选择约100个有趣的突变体组进行进一步研究。在试点实验中，已经发现了一些有趣的突变体，这些突变体将在本项目中进行研究。其中一些突变体，包括一个具有明显“矮化”表型的突变体，将用于测试一种分离突变基因的新方法。这也需要生成用于诱变的基因型的草图基因组序列。该矮突变体还将测试其育性，以确定在未来的诱变研究中是否可行。该项目的成果将是：(1)建立有史以来第一个马铃薯突变体收集。(2)龙葵“碱基型”基因组序列草图的阐明。(3)鉴定一个或多个突变体的候选基因和突变等位基因。

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.