scholarly journals Estimates of genetic selection gain in irrigated F3 rice families

Científica ◽  
2020 ◽  
Vol 48 (2) ◽  
pp. 139
Author(s):  
Gabriela De Magalhães da Fonseca ◽  
Maicon Nardino ◽  
Marina De Magalhães da Fonseca ◽  
Viviane Koop Da Luz ◽  
Ariano Martins de Magalhães Júnior ◽  
...  
2006 ◽  
Vol 54 (3) ◽  
pp. 343-350 ◽  
Author(s):  
C. F. H. Longin ◽  
H. F. Utz ◽  
A. E. Melchinger ◽  
J.C. Reif

The optimum allocation of breeding resources is crucial for the efficiency of breeding programmes. The objectives were to (i) compare selection gain ΔGk for finite and infinite sample sizes, (ii) compare ΔGk and the probability of identifying superior hybrids (Pk), and (iii) determine the optimum allocation of the number of hybrids and test locations in hybrid maize breeding using doubled haploids. Infinite compared to finite sample sizes led to almost identical optimum allocation of test resources, but to an inflation of ΔGk. This inflation decreased as the budget and the number of finally selected hybrids increased. A reasonable Pk was reached for hybrids belonging to the q = 1% best of the population. The optimum allocations for Pk(q) and ΔGkwere similar, indicating that Pk(q) is promising for optimizing breeding programmes.


Peanuts are plants of the tropical zone, therefore, for its growth and development, high temperature indicators are needed during a fairly long growing season. The climatic parameters of the south of Ukraine correspond to the needs of this culture, and today there is positive experience in growing peanuts in this region. In order to increase the efficiency of growing peanuts in the conditions of the Steppe zone, it is necessary to carry out genetic selection work to study and select a more adapted source material in order to create highly productive Ukrainian varieties adapted to the arid zone conditions. At the initial stage of this work, it is necessary to have clear signs and characteristics for evaluating the studied genotypes, and the existing methods for describing the characters and conducting an examination for distinctness, uniformity, and stability are incomplete and do not meet the requirements for in-depth work on private genetics and culture breeding. For our work, we used 18 peanut genotypes as a material, which make up the collection of the Institute of Oilseeds of NAASU. Studies were carried out in 2018 and 2019, in different weather conditions. All measurements, observations and statistical processing in the study of samples were carried out in accordance with generally accepted methods. When conducting a comparative analysis of the two methods for describing the signs of underground peanuts, it was found that one of the methods contains 23 signs and the other 17. The signs of the vegetative part of plants that characterize the habit and structure of the leaf predominate in both methods. We have identified and proposed for description 9 new characters in peanut plants: 2 - leaf characters (additional leaves and pubescence); 1 - the structure of beans (weight 100 beans); 1 - an economically valuable trait (the presence of nodules on the roots); 5 - flower features (size and color of the flower and border). In terms of plant habitat, Ukrainian Stepnyak and Krasnodar 13 varieties were distinguished, which had the highest height (43.8 cm) and the largest number of branches (9.3 pcs.). In addition to morphological identification features for the description and examination of distinctness, uniformity and stability, we have also studied the quantitative characteristics of underground peanuts. It was established that the height of peanut plants in the field conditions of the south of Ukraine ranged from 14 to 44 cm. The highest variety was the Ukrainian Stepnyak variety, and the shortest one was Pink large. The largest number of branches is 9.3 pcs. noted in the variety Krasnodar 13, and the smallest 4.62 pcs. - at L3. And the largest flower of 1.91 cm stood out White-pink 3. The quantitative traits we studied are characterized by continuous variability, which is due to the interaction between genes and the environment. Thus, to identify varietal variability in underground peanuts, it is necessary to use both existing methods, and in the near future, work should be done to combine them with the inclusion of new identified characters to more clearly identify the genotypes of this new valuable oilseed crop.


2019 ◽  
Author(s):  
Marta Soniewicka ◽  
Wojciech Lewandowski
Keyword(s):  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Simone Savoia ◽  
Andrea Albera ◽  
Alberto Brugiapaglia ◽  
Liliana Di Stasio ◽  
Alessio Cecchinato ◽  
...  

Abstract Background The possibility of assessing meat quality traits over the meat chain is strongly limited, especially in the context of selective breeding which requires a large number of phenotypes. The main objective of this study was to investigate the suitability of portable infrared spectrometers for phenotyping beef cattle aiming to genetically improving the quality of their meat. Meat quality traits (pH, color, water holding capacity, tenderness) were appraised on rib eye muscle samples of 1,327 Piemontese young bulls using traditional (i.e., reference/gold standard) laboratory analyses; the same traits were also predicted from spectra acquired at the abattoir on the intact muscle surface of the same animals 1 d after slaughtering. Genetic parameters were estimated for both laboratory measures of meat quality traits and their spectra-based predictions. Results The prediction performances of the calibration equations, assessed through external validation, were satisfactory for color traits (R2 from 0.52 to 0.80), low for pH and purge losses (R2 around 0.30), and very poor for cooking losses and tenderness (R2 below 0.20). Except for lightness and purge losses, the heritability estimates of most of the predicted traits were lower than those of the measured traits while the genetic correlations between measured and predicted traits were high (average value 0.81). Conclusions Results showed that NIRS predictions of color traits, pH, and purge losses could be used as indicator traits for the indirect genetic selection of the reference quality phenotypes. Results for cooking losses were less effective, while the NIR predictions of tenderness were affected by a relatively high uncertainty of estimate. Overall, genetic selection of some meat quality traits, whose direct phenotyping is difficult, can benefit of the application of infrared spectrometers technology.


Genus ◽  
2020 ◽  
Vol 76 (1) ◽  
Author(s):  
Jacques Vallin

Abstract Many more cases of supercentenarians are observed in the French Départements d’Outre-Mer (DOM) than in metropolitan France. A first possible explanation is that the standard French protocol for validating age does not sufficiently cover DOMs. However, if additional checks can confirm the verity of this phenomenon, forming explanatory hypotheses can be relevant and quite interesting. Thanks to an INED research funding, a special protocol of deep age checking has been established to be applied to the two DOMs where the phenomenon is the most pronounced: Guadeloupe and Martinique. First results not only show that combining several additional checks does not leave much room for further doubting the ages of supercentenarians but they also support some arguments in favor of a possible fundamental explanation: genetic selection due to the extreme severity of mortality inflicted on their slave ancestors.


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