Plant Breeding Chapter 15 Synthetic Cultivars in Crossfertilized

Plant Breeding Chapter 15 Synthetic Cultivars in Crossfertilized Crops 异花受精作物的综合品种

Synthetic Cultivars in Cross-fertilized Crops Contents 主要内容 Conception of Synthetic cultivars 综合品种的概念 Breeding system for synthetic cultivar development 培育综合品种的育种系统 Outline of a practical program for developing synthetic cultivar 培育综合品种的操作程序要点 Layout of the polycross in field 田间多系杂交的设计 Performance of Synthetic Cultivars 综合品种的表现 Advantages and Disadvantages of Synthetic Cultivars 综合品种的优点和缺点

Synthetic Cultivars in Cross-fertilized Crops 1 Conception of Synthetic cultivars 综合品种的概念 ① Synthetic cultivars: advanced generations of cross-fertilized seed mixtures of a few selected parents 综合品种：异花受精作物几个入选亲本混合种子的高代后代 ② Open-pollinated cultivar: developed by mass selection, maintained by further mass selection 开放授粉品种：来源于混合选择，可由混合选择保存 ③ Pure-line cultivar: originating from a single plant selection, maintained by self-fertilization 纯系品种：来源于单株选择，可由自交保存

Synthetic Cultivars in Cross-fertilized Crops 2 Breeding system for synthetic cultivar development 培育综合品种的育种系统 A. polycross多系杂交 B. Principle: each clone pollinated by approximately the same pollen sources 原理：利用基本相同的花粉给每个植物授粉 C. By polycross, 50 to 100 plants was selected for producing seed for progeny testing 利用多系杂交时，选择 50 -100个植株生产用于后代测验的种子 D. Superior synthetic cultivar will be gotten by cross-fertilizing 4 to 5 high-combining, superior clones 优良综合品种可以通过4 -5个表现优良、配合力高的品系之间的 多系杂交获得

Synthetic Cultivars in Cross-fertilized Crops 3 Outline of a practical program for developing a synthetic cultivar 培育综合品种操作程序概要 ① Sources of breeding materials for synthetic cultivar 用于综合品种培育的育种材料的来源 A. Old stands, introductions 旧的类群，引进材料 B. Landrace cultivars, synthetics 地方品种，综合品种 C. Hybrid progenies 杂种后代 D. Materials produced in a breeding program 育种中间材料 E. Cultivars with desirable genes 具有优良性状的品种 F. Other source with desirable genes 其它具有优良性状的材料

Synthetic Cultivars in Cross-fertilized Crops ② Program for synthetics with disease resistance 抗病综合品种的选育程序 A. Establishing a source nursery with 5, 000 to 10, 000 individual plants, and screening for disease resistance 建立具有5000 -10000个植株的资源圃，进行抗病性筛选 B. 50 to 150 agronomically desirable plants with satisfactory disease resistance are selected, and have been cross-fertilization 50 -150个抗病性好、农业性状优良的植株入选，并进行 异花受精

Synthetic Cultivars in Cross-fertilized Crops C. D. Testing the GCA of each of the selected plants, and the top of 5 to 12 plants (S 0)will be used to produce a synthetics in a polycross nursery 测定每个植株的GCA，表现最好的5 -12个植株种植于多系 杂交圃用于生产综合品种 The S 0 parents are vegetatively propagated and planted in isolation to cross-fertilize and produce S 1 seed for commercial multiplication S 0亲本利用营养体进行繁殖并隔离种植，以生产S 1商品种子

Synthetic Cultivars in Cross-fertilized Crops 4 Layout of the polycross in field 田间多系杂交的实施 ① Aim and principle of polycross 多系杂交的目的和原则 A. Providing information on the GCA of plant material 为植物材料的GCA测定提供信息 B. Seed produced on each material is pollinated by as many of other material under test as possible 生产种子时每个植株要尽可能多的接受其它待测材 料的花粉 C. Seed of each clone is harvested separately 每棵植物上的种子单独收获

Synthetic Cultivars in Cross-fertilized Crops ② Layout of polycross in field 多系杂交的田间实施 A. For small number of material 当材料数量较少时 a. Propagating each of material into the number of material under test 繁殖每个材料达到测验所需的数目 b. The resulting materials are arranged in a square plot 所获得的材料按方形小区排列

Synthetic Cultivars in Cross-fertilized Crops B. For large number of material (grid system) 当材料数量较多时（格子系统） a. All materials are represented in any one grid 所有材料在任何一个格子中都会出现 b. Material within each grid has two different adjacent material to ensure highly mixed pollination 每个格子中任何材料都与不同的材料相邻，以确保高度 混合授粉

Synthetic Cultivars in Cross-fertilized Crops ③ Advantages of the polycross test method 多系杂交法的优点 A. Sufficient seed can be obtained 能够获得足够多的种子 B. Providing a wide array of cross-combinations and genotypes as additional source material 可以提供大量的杂交组合和基因型作为育种材料 C. A more efficient evaluation of GCA than from a diallel crossing system 对GCA估计的效率要高于双列杂交系统 D. The resulting synthetic cultivars are less likely to suffer genetic shifts during the normal process of seed increase 所获得的综合品种在种子正常扩繁过程中不会发生遗传 漂移

Synthetic Cultivars in Cross-fertilized Crops ④ Disadvantages of the Polycross Test Method 多系测验法的缺点 A. Male parentage may be confounded 父本来源不清 B. Failure to ensure completely random pollination under inadequate replication and isolation 在重复和隔离不足的情况下很难保证完全随机授粉

Synthetic Cultivars in Cross-fertilized Crops 5 Performance of Synthetic Cultivars 综合品种的表现 A. Synthetic cultivars of S 3 and S 4 are not as high in performance as the S 1 generation 综合品种S 3和 S 4代的表现不如S 1 B. Formula to predict the F 2 yield of a group of inbred parents 多个自交系亲本F 2代产量的预测公式 F 2=F 1－(F 1 －P)/n F 2: expected performance of the F 2代的期望值 F 1: mean F 1 performance of combinations of inbred lines 所有自交系杂交组合F 1的平均表现 P: average performance of inbred lines 自交系的平均表现 n: number of inbred lines 自交系数目

Synthetic Cultivars in Cross-fertilized Crops 6 Advantages and Disadvantages of Synthetic Cultivars 综合品种的优缺点 ① Advantage 优点 A. A compromise between maintaining heterosis and economical seed production 兼顾了杂种优势保持和种子大量生产 B. Sources of genetic variation for inbred lines to develop hybrid 为自交系选育提供遗传变异，以培育杂种一代 ② Disadvantage 缺点 A. Tends to lessen the emphasis on choosing parents that show heterosis 在亲本选择方面不及杂种优势育种

Synthetic Cultivars in Cross-fertilized Crops Exercise 思考题 What is the main steps for the production of synthetic cultivar? 生产综合品种的主要步骤是什么？ What is the advantage and disadvantage of synthetic cultivar? 综合品种的优缺点是什么？