Genetic markers and the selection of quantitative traits in forage grasses

Euphytica ◽  
1994 ◽  
Vol 77 (3) ◽  
pp. 269-275 ◽  
Author(s):  
M. D. Hayward ◽  
N. J. Mcadam ◽  
J. G. Jones ◽  
C. Evans ◽  
G. M. Evans ◽  
...  
Author(s):  
M. D. Hayward ◽  
N. J. McAdam ◽  
J. G. Jones ◽  
C. Evans ◽  
G. M. Evans ◽  
...  

Author(s):  
Bruce Walsh ◽  
Michael Lynch

Quantitative traits—be they morphological or physiological characters, aspects of behavior, or genome-level features such as the amount of RNA or protein expression for a specific gene—usually show considerable variation within and among populations. Quantitative genetics, also referred to as the genetics of complex traits, is the study of such characters and is based on mathematical models of evolution in which many genes influence the trait and in which non-genetic factors may also be important. Evolution and Selection of Quantitative Traits presents a holistic treatment of the subject, showing the interplay between theory and data with extensive discussions on statistical issues relating to the estimation of the biologically relevant parameters for these models. Quantitative genetics is viewed as the bridge between complex mathematical models of trait evolution and real-world data, and the authors have clearly framed their treatment as such. This is the second volume in a planned trilogy that summarizes the modern field of quantitative genetics, informed by empirical observations from wide-ranging fields (agriculture, evolution, ecology, and human biology) as well as population genetics, statistical theory, mathematical modeling, genetics, and genomics. Whilst volume 1 (1998) dealt with the genetics of such traits, the main focus of volume 2 is on their evolution, with a special emphasis on detecting selection (ranging from the use of genomic and historical data through to ecological field data) and examining its consequences. This extensive work of reference is suitable for graduate level students as well as professional researchers (both empiricists and theoreticians) in the fields of evolutionary biology, genetics, and genomics. It will also be of particular relevance and use to plant and animal breeders, human geneticists, and statisticians.


Genetika ◽  
2014 ◽  
Vol 46 (2) ◽  
pp. 545-559 ◽  
Author(s):  
Mirjana Jankulovska ◽  
Sonja Ivanovska ◽  
Ana Marjanovic-Jeromela ◽  
Snjezana Bolaric ◽  
Ljupcho Jankuloski ◽  
...  

In this study, the use of different multivariate approaches to classify rapeseed genotypes based on quantitative traits has been presented. Tree regression analysis, PCA analysis and two-way cluster analysis were applied in order todescribe and understand the extent of genetic variability in spring rapeseed genotype by trait data. The traits which highly influenced seed and oil yield in rapeseed were successfully identified by the tree regression analysis. Principal predictor for both response variables was number of pods per plant (NP). NP and 1000 seed weight could help in the selection of high yielding genotypes. High values for both traits and oil content could lead to high oil yielding genotypes. These traits may serve as indirect selection criteria and can lead to improvement of seed and oil yield in rapeseed. Quantitative traits that explained most of the variability in the studied germplasm were classified using principal component analysis. In this data set, five PCs were identified, out of which the first three PCs explained 63% of the total variance. It helped in facilitating the choice of variables based on which the genotypes? clustering could be performed. The two-way cluster analysissimultaneously clustered genotypes and quantitative traits. The final number of clusters was determined using bootstrapping technique. This approach provided clear overview on the variability of the analyzed genotypes. The genotypes that have similar performance regarding the traits included in this study can be easily detected on the heatmap. Genotypes grouped in the clusters 1 and 8 had high values for seed and oil yield, and relatively short vegetative growth duration period and those in cluster 9, combined moderate to low values for vegetative growth duration and moderate to high seed and oil yield. These genotypes should be further exploited and implemented in the rapeseed breeding program. The combined application of these multivariate methods can assist in deciding how, and based on which traits to select the genotypes, especially in early generations, at the beginning of a breeding program.


Trees ◽  
2020 ◽  
Vol 34 (5) ◽  
pp. 1323-1334
Author(s):  
Niu Yu ◽  
Qiongqiong Li ◽  
Jinchang Yang ◽  
Guangtian Yin ◽  
Rongsheng Li ◽  
...  

Key message Geography and tree diameter were the major factors in determining oleoresin yield in Sindora glabra. The tangential diameter and area of secretory canals are reliable indicators of the oleoresin amount. Abstract Sindora glabra is a native tropical plant of China that exudes copious amounts of oleoresin from wounds on the stem. Elucidation of the mechanism affecting the oleoresin yield is of particular importance for development and selection of superior germplasm. In this study, the variation in oleoresin yield and anatomical traits of the stem of S. glabra were investigated in four main natural populations in Hainan. The results showed that annual oleoresin yield varied considerably among populations. The oleoresin yield exhibited an increasing trend with the increment of tree stem diameter until the diameter was over 80 cm. Moreover, oleoresin production in the wet season was higher than in dry season. The analysis of oleoresin chemical composition indicated that the four populations belong to the same chemotype despite the amount of four types of sesquiterpenes varying greatly among areas. Anatomical analysis revealed that quantitative traits of secretory canals including tangential diameter, area, density and frequency were significantly different among populations and tree diameters. Furthermore, the tangential diameter and area of secretory canals were positively correlated with oleoresin yield. These results suggested that the tangential diameter and area of secretory canals are reliable indicators of the oleoresin amount and can be used for selection purposes in S. glabra.


2010 ◽  
Vol 11 (2) ◽  
pp. 36
Author(s):  
D. Swerdlow ◽  
R. Sofat ◽  
T. Shah ◽  
K. Kuchenbaecker ◽  
J. Mindell ◽  
...  

Genome ◽  
1993 ◽  
Vol 36 (1) ◽  
pp. 1-7 ◽  
Author(s):  
R. A. Morton

The impact of insecticide resistance is well documented. It includes the toxic effects of pesticides on the environment and the cost of the increased amounts of insecticides required to effectively control resistant insects. Resistance evolves by the selection of genes that confer tolerance to insecticides. Several resistance genes have been identified and cloned in Drosophila, including genes for mutant target molecules and genes that increase insecticide degradation. Drosophila is a useful system to understand the evolution of quantitative traits in general as well as the population genetics of insecticide resistance. Through it, we may hope to understand the relationship between discrete genetic change and continuously varying characters. In addition, molecular genetic techniques developed using Drosophila can eventually be transferred to other insects in order to help control pest populations.Key words: insecticide resistance, evolution of tolerance, selection of resistant genes, molecular genetics, Drosophila.


2018 ◽  
pp. 53-59
Author(s):  
Oleksandr Drozd ◽  
Yevhen Zaika ◽  
T Pyvovar

In the first and second generation of hybrids revealed different character of inheritance of basic qualitative and quantitative traits – dominance, heterosis, over-domination and intermediate inheritance, which allows to assume high efficiency of individual selections in the following generations, with the selection of transgressive forms. The actual ratio of distribution groups in F2 hybrids and the genetic control of these traits in parental forms by weight of 1000 seeds were determined. The source material and the perspective hybrid combinations in the breeding nursery were studied and the perspective numbers were distinguished according to the complex of features.


Author(s):  
M. Samuel Jeberson ◽  
K. S. Shashidhar ◽  
Amit Kumar Singh

Analysis of genetic variability, heritability, correlation, path analysis, principal component and cluster analysis was carried for 25 blackgram genotypes grown in the foothills of Manipur. The results showed that phenotypic coefficients of variability recorded were higher than the genotypic coefficients of variability, irrespective of traits, demonstrating the effect of environment thereon. The present study revealed that the heritability (bs) estimates were maximum (>50%) for the traits such as days taken to attain the 50% flowering, number of clusters/plant, number of pods/plant and 100 seed weight. The correlation and path analysis proved the selection of the yield attributes in blackgram based on the characters, viz., number of pods/plant and number of cluster/plants. The first three principal components, having the Eigen values more than 1, contributed 84.52% towards variability among the 25 genotypes screened for quantitative traits. Based on the average linkage, 25 genotypes were grouped into five (5) clusters.


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