BREEDING FOR YIELD STABILITY IN UNPREDICTABLE ENVIRONMENTS - SINGLE TRAITS, INTERACTION BETWEEN TRAITS, AND ARCHITECTURE OF GENOTYPES
BREEDING FOR YIELD STABILITY IN UNPREDICTABLE ENVIRONMENTS - SINGLE TRAITS, INTERACTION BETWEEN TRAITS, AND ARCHITECTURE OF GENOTYPES
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DOI：
10.1007/bf00042061
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发表时间：
1991-07-01
期刊：
影响因子：
1.9
通讯作者：
GRANDO, S
中科院分区：
文献类型：
--
作者：
CECCARELLI, S;ACEVEDO, E;GRANDO, S
在作物产量不受胁迫或仅受可预测胁迫影响的环境中，尝试鉴定用作谷物产量的间接测量的个体性状已显示出一定程度的成功。然而，分析育种在以下情况下基本上是不成功的：a）由于许多气候胁迫的频率、时间、持续时间和严重程度的高度可变性，以低产量为特征的胁迫环境，和B）其中主要目标是更大产量稳定性（定义为减少作物歉收频率）的育种计划。实验证据表明，当环境变异性很高，由于不可预测的频率，时间和各种气候压力的严重程度的差异，每次不同的几个特征的组合可能会赋予“抗旱性”。性状间的相互作用决定了作物对各种胁迫的总体反应，在特定的胁迫条件下，性状间的相互作用有时会增强特定性状的重要性。在这种情况下，就很难将“抗旱性”看作是一个在遗传方面具有自身特性的性状。基于等基因系的性状评估和验证往往过于简化性状之间的相互作用，因为这种方法只提供了关于特定性状在特定遗传背景下的影响的信息。在群体组织水平上，选择单个性状和性状的特定组合之间的困境可以转化为选择单个基因型和基因型的特定组合之间的困境。证据表明，自然选择在压力条件下一直无法确定一个单一的性状或一个单一的基因型与给定的“适应”结构的性状，讨论有关种质开发philosphies稳定产量在不可预测的压力环境。
Attempts to identify individual traits to use as an indirect measure for grain yield have shown some degree of success in environments where crop yields are affected by no stress or only by predictable stresses. However, analytical breeding has been largely unsuccessful in the case of a) stressful environments characterized by low yields due to high variability in the frequency, timing, duration and severity of a number of climatic stresses, and b) breeding programs where the major objective is greater yield stability defined as a reduction in the frequency of crop failures. Experimental evidence suggests that, when environmental variability is high due to unpredictable differences in frequency, timing and severity of various climatic stresses, each time different combinations of several traits are likely to confer 'drought resistance'. Interaction among traits in determining overall crop response to variable stresses is expected to occasionally enhance the importance of a specific trait in a specific stress situation. In this context it becomes difficult to consider 'drought resistance' as a character with its own identity in terms of inheritance.Assessment and verification of traits based on the use of isogenic lines tends to oversimplify the interactions between traits, as the approach provides information on the effect of a specific trait only in a specific genetic background.At the population level of organisation, the dilemma between selection for individual traits and specific combinations of traits can be translated into the dilemma between selection for individual genotypes and specific combinations of genotypes. The evidence that natural selection under stress conditions has not been able to identify either a single trait or a single genotype with a given 'adapted' architecture of traits, is discussed in relation to germplasm development philosphies to stabilize yield in unpredictably stressed environments.