玉米的遗传结构 玉米的开花时间
Edward S Buckler1, James B Holland, Peter J Bradbury
1U.S. Department of Agriculture (USDA)-Agricultural Research Service (USDA-ARS), USA. esb33@cornell.edu
概括
玉米的开花时间是由许多小效果定量特征位点 (QTLs) 控制的,而不是单个基因. 一个简单的附加模型准确地预测了Zea mays.中的这个复杂的特征.
科学领域:
- 植物遗传学 植物遗传学
- 定量性质特征遗传学 遗传学
- 玉米 (Zea mays) 的适应性
背景情况:
- 开花时间是植物的关键适应性特征,影响生存和繁殖.
- 了解开花时间的遗传基础是提高作物的关键.
- 齐亚梅斯 (Zea mays) 是一种杂交物种,表现出复杂的开花时间变化.
研究的目的:
- 剖析玉米花期变化的遗传结构.
- 在一大种玉米种群中,确定控制花期的定量特征位点 (QTL).
- 为了比较玉米的开花时间的遗传基础,与米和阿拉比多普西斯等自食物种进行比较.
主要方法:
- 利用了玉米嵌协会映射 (NAM) 种群,包括5000个重组杂交系.
- 在八个不同的环境中测试了近100万种植物.
- 采用定量特征位置 (QTL) 映射来分析遗传变异.
主要成果:
- 没有检测到花期的单一大效应的QTL.
- 发现了许多小效应的QTLs的证据,跨家族共享.
- 基因效应在创始人系之间有所不同,没有显著的地理或史学影响.
- 一个简单的添加模型有效地预测了玉米的开花时间.
结论:
- 玉米的开花时间由多基因架构与众多小效应的QTLs所支配.
- 基变异和添加效应是主要的驱动因素,与同类物种中复杂的相互作用不同.
- 这些发现提供了对玉米适应和育种策略的见解.
相关概念视频
Light Acquisition
In order to produce glucose, plants need to capture sufficient light energy. Many modern plants have evolved leaves specialized for light acquisition. Leaves can be only millimeters in width or tens of meters wide, depending on the environment. Due to competition for sunlight, evolution has driven the evolution of increasingly larger leaves and taller plants, to avoid shading by their neighbors with contaminant elaboration of root architecture and mechanisms to transport water and nutrients.
Biological Clocks and Seasonal Responses
The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod.
Morphogenesis
Plant morphogenesis—the development of a plant’s form and structure—involves several overlapping developmental processes, including growth and cell differentiation. Precursor cells differentiate into specific cell types, which are organized into the tissues and organ systems that make up the functional plant.
Dihybrid Crosses
Overview
Chi-square Analysis
The chi-square test is a statistical hypothesis test. It is used to check whether there is a significant difference between an expected value and an observed value. In the context of genetics, it enables us to either accept or reject a hypothesis, based on how much the observed values deviate from the expected values.
The chi-square test was developed by Pearson in 1990.
The first step of performing a Chi-square analysis is to establish a null hypothesis, which assumes that there is no real...
The chi-square test was developed by Pearson in 1990.
The first step of performing a Chi-square analysis is to establish a null hypothesis, which assumes that there is no real...
Law of Segregation
When crossing pea plants, Mendel noticed that one of the parental traits would sometimes disappear in the first generation of offspring, called the F1 generation, and could reappear in the next generation (F2). He concluded that one of the traits must be dominant over the other, thereby causing masking of one trait in the F1 generation. When he crossed the F1 plants, he found that 75% of the offspring in the F2 generation had the dominant phenotype, while 25% had the recessive phenotype.


