chapter 18 Mutation__ Breeding.ppt

1、Chapter 18,Mutation Breeding 突变育种,Introduction 引言 Induced Mutations 诱导突变 Induced versus Spontaneous Mutations诱导vs自发突变 The Nature of Mutations 突变的性质 Mutation Breeding Systems 突变育种系统 Mutations in Vegetatively Propagated Crops营养繁殖作物的突变 Biotechnology and Mutation Breeding 生物技术和突变育种,Contents 主要内容,Definit

2、ion of mutation 突变的定义 A sudden modification in a gene or chromosome基因或染色体的突然改变 The sources of genetic variability for plant breeding植物育种遗传变异的来源,1 Introduction 引言,Classification of mutation 突变的分类 Spontaneous mutations and induced mutation自发突变和诱导突变 Heritable and not heritable可遗传和不可遗传 Desirable and und

3、esirable 优良的和不良的 Spontaneous mutation may not provide variation fast enough to meet the accelerating human needs自发突变不能为人们需求的提供足够快的变异,Mutation breeding突变育种 人为的采用物理、化学的因素，诱发植物产生遗传物质的突变，经选择和培育成为新品种的途径。 目的：突破原有基因变异库的限制 手段：电离辐射、化学诱变 基础：基因突变或染色体结构变异 问题：遗传机制尚不清楚,Significance of mutation breeding 突变育种的意义 育成

4、大量植物新品种 创造新的基因型，丰富作物原有的“基因库” 提高突变频率 缩短育种年限 Characteristic of mutation breeding 突变育种的特点 变异方向和性质的不确定性 适于进行个别性状的改良 亲本选择 有利突变的机率低 突变普通常遵循突变本身的规律,2 Induced Mutations 诱导突变,Physically induced mutations 物理诱变 Mutagens 诱变剂 Ionizing mutagenic agents 电离化诱变剂 None ionizing mutagenic agents 非电离化诱变剂 Space induced m

5、utations 空间诱变,Ionizing mutagenic agents 电离化诱变剂,Neutron 中子,None ionizing mutagenic agents 非电离化诱变剂,Ultraviolet radiation 紫外线,Laser 激光,电离辐射,电磁辐射,不带电粒子,X射线,射线,射线,射线,质子,中子,紫外线,诱变育种中利用的辐射种类,粒子辐射,非电离辐射,带电粒子,激光,Space Induced Mutations 空间诱变,处理方式 外照射 内照射 浸泡法 注射或涂抹法 饲喂法（施肥法） 急性照射 慢性照射 重复照射,Organ applied to ind

6、uced mutation for physical mutagens 用于物理诱变的器官 Seeds 种子 Vegetative organs 营养器官 Pollen 花粉 Plants 生长植株 Ovary 子房 Somatic tissue or cells 营养体组织或细胞,To determine effective dosage rates 确定有效剂量 Different crops react differently to mutagens不同作物对诱变剂的反应不同 Different cultivars react differently to mutagens不同品种对诱变

7、剂的反应不同 For new crops, the half lethal dosage (LD50, killing 50% of the seeds or seedlings) was suggested对于新作物来说，建议使用半致死剂量 The mechanisms of physically induced mutation物理诱变的机理,Chemically induced mutations 化学诱变 Mutagens 诱变剂 烷化剂 烷基磺酸盐和烷基硫酸盐类 亚硝基烷基化合物 次乙亚胺和环氧乙烷类 芥子气类 核酸碱基类似物 其他诱变剂 Sodium azide 叠氮钠 Certa

8、in base substitution nitroso compounds 特定元素被替代的亚硝基化合物,Alkylation mutagens: can induce high ratios of chromosome aberrations and mutations烷化剂：能诱发高频率的染色体缺失和突变 Sodium azide: can induce gene mutations but not chromosomal changes (point mutations)叠氮钠：能诱发基因突变而不致引起染色体变化（点突变） Treatment with chemical mutagen

9、s 化学诱变剂处理 Soaking seeds, buds, roots and dormant cutting in a solution of the chemical mutagens将种子、花芽和休眠插条浸泡在化学诱变剂的溶液中,3 Induced versus spontaneous mutations诱导vs自发突变,Difference 区别 No major detectable differences 无显著差异 Older spontaneous mutants: an evolutionary process of coadaptation through recombi

10、nation and natural selection老自发突变体：通过遗传重组和自然选择经历了一个共适应的进化过程 New spontaneous or induced mutants: not to be shaped into such complexes新自发突变体或诱发突变体：没有经历如此复杂的过程,The value of induced mutations 诱发突变的价值 Desired changes can be incorporated directly into agronomically desirable genotype优良变化可以直接整合到农业性状优良的基因型中

11、 Can produce mutants that have not arisen or have been lost in recent evolutionary history可以产生近代没有出现过的或丢失的突变体 To play an important role in identifying specific genes在鉴定特定基因方面有重要作用,4 The nature of mutations 突变的性质,The process of inducing mutations is random诱导突变的过程是随机的 The direction of mutations are re

12、cessive (A to a) or partially recessive突变的方向是隐性或部分隐性的 The mutation frequencies is uncertain突变频率是不确定的 A mutation is seldom induced in a single gene很少会出现单个基因被诱变的情况 Mutations may occur in both qualitatively and quantita-tively inherited traits质量和数量性状都会被诱变,5 Mutation Breeding Systems 突变育种系统,Requiring la

13、rge plant populations 要求有大的植物群体 Only 10% of induced mutations are useful只有10%的诱导突变是有用的 Minor but useful mutations are difficult to identify by visual means微小但有用的突变很难用肉眼鉴别 Selection methods of M2 and their progeny M2及其后代的选择法 The Pedigree System 系谱选择法 The Bulk Method 集团选择法,6 Mutations in Vegetatively

14、Propagated Crops营养繁殖作物的突变,Success of induced mutations has been rather limited诱发突变所取得的成功非常有限 The difficulty of producing large populations产生较大的群体比较困难 The lack of efficient screening techniques in early stages of development 在培育的早期缺少高效的筛选技术 The long time required to assess clearly the superior genoty

15、pe under field conditions在大田中清楚地评价优良基因需要很长时间 Interfere of chimera 嵌合体的干扰,突变体分离技术 分离繁殖法 短截修剪法 不定芽技术 组织培养法,7 Biotechnology and Mutation Breeding生物技术与突变育种,Application of mutation breeding in biotechnology突变育种在生物技术上的应用 Gene location on a specific chromosome, such as trisomics (2n+1) , monosomics (2n-1), translocation将基因定位于特定染色体上，如三体、单体、易位 Application of biotechnology in mutation breeding生物技术在突变育种上的应用 The use of cell cultures, protoplasts, pollen and callus to induce mutations, such as somatic variation使用细胞培养、原生质体、