scholarly journals Efficiency of selection in early generations of potato families with a view toward heat tolerance

2015 ◽  
Vol 15 (4) ◽  
pp. 210-217 ◽  
Author(s):  
Izabel Cristina Rodrigues de Figueiredo ◽  
César Augusto Brasil Pereira Pinto ◽  
Guilherme Henrique Martins Rodrigues Ribeiro ◽  
Leandro de Oliveira Lino ◽  
Danilo Hottis Lyra ◽  
...  
Keyword(s):  
Heat Tolerance ◽  
Tuber Shape ◽  
Family Selection ◽  
Clonal Generation ◽  
Seedling Generation ◽  
The Mean ◽  
Selection For ◽  
Efficiency Of Selection ◽  
Tuber Specific Gravity ◽  
Selection Of

Abstract The aim of this study was to evaluate the efficiency of selection of potato families in early generations for heat tolerance. Thirty families were evaluated in the seedling generation (SG), first clonal generation (FCG) in the field and greenhouse under high temperature conditions, and second clonal generation (SCG) under mild temperatures. The mean of the families was obtained in each generation. The 16 most productive families in FCG were selected, and the clones of these families were evaluated in experiments in the winter and rainy crop seasons. The results showed that family selection for tuber shape may be applied as of the SG. It was also observed that family selection in the FCG and SCG for yield and tuber specific gravity contributed to identification of clones tolerant to heat and responsive to environmental improvement.

scholarly journals Expected response to early-generation selection for yield and tuber appearance traits in potatoes

2016 ◽  
Vol 37 (5) ◽  
pp. 2849 ◽  
Author(s):  
Vicenti Gonçalves Ney ◽  
Laerte Reis Terres ◽  
Giovani Olegário da Silva ◽  
Arione Da Silva Pereira
Keyword(s):  
Tuber Yield ◽  
High Heritability ◽  
Clonal Generation ◽  
Seedling Generation ◽  
Selection For ◽  
Group 2 ◽  
Selection Of ◽  
Made In ◽  
Eye Depth ◽  
Group 1

The aim of this study was to evaluate the performance of potato clonal families, and to estimate genetic variance, heritability and the expected response to selection of tuber yield and appearance traits in early generations. Twelve potato families were obtained from crosses between two groups of randomly-selected genotypes, including Eliza, C1730-7-94, and C-1742-8-95 in group 1; and Shepody, Asterix, Caesar, and White Lady in group 2. The crosses were made in factorial design (3 genotypes x4 genotypes), and each family consisted of 75 genotypes. Experiments were conducted in the fall of 2010, with a seedling generation under greenhouse conditions, and in the fall of 2011, with a clonal generation under field condition. High heritability estimates suggest that mild to moderate selection can be applied in the seedling generation to eye depth, eyebrow prominence, tuber curvature, flattening and shape uniformity. The C1742-8-95/White Lady stood out as a superior cross, as did all other crosses with White Lady, regarding tuber appearance and yield traits.

scholarly journals Repeatability of family means in early generations of potato under heat stress

2011 ◽  
Vol 11 (4) ◽  
pp. 330-337 ◽  
Author(s):  
César Augusto Ticona Benavente ◽  
César Augusto Brasil Pereira Pinto ◽  
Izabel Cristina Rodrigues de Figueiredo ◽  
Guilherme Henrique Martins Rodrigues Ribeiro
Keyword(s):  
Specific Gravity ◽  
Tuber Yield ◽  
Warm Season ◽  
Family Selection ◽  
Adjusted Means ◽  
The Family ◽  
Family Level ◽  
Clonal Generation ◽  
Seedling Generation ◽  
Selection Of

The selection of potato clones for yield is usually effective from the second clonal generation. It would however be ideal to select from the seedling generation (SG) or the first clonal generation (FCG). The aim of this study was to evaluate the repeatability of selection at the family level performed in the early generations with the subsequent generations, for tuber yield and specific gravity in the warm season. Thirty families were evaluated in the SG, FCG and the second, third and fourth clonal generation, without any selection. In this way, adjusted means of the 30 families were obtained for each generation. Selections were simulated independently in the different family generations, and then the repeatability of these families among generations verified, using the same selection intensity. The results showed that the family selection in the SG and FCG for specific gravity and in the FCG for tuber yield is efficient, at mild as well as warm temperatures.

Introduction of helical computed tomography affects patient selection for V/Q lung scan

2002 ◽  
Vol 41 (02) ◽  
pp. 91-94 ◽  
Author(s):  
G. Zettinig ◽  
S. Baudrexel ◽  
Th. Leitha
Keyword(s):  
Computed Tomography ◽  
Helical Computed Tomography ◽  
Lung Scan ◽  
The Mean ◽  
Low Probability ◽  
Selection For ◽  
Lung Scanning ◽  
Selection Of Patients ◽  
Selection Of

Summary Aim: Retrospective analysis for determination of the effect of helical computed tomography (HCT) on utilization of V/Q lung scanning to diagnose pulmonary embolism (PE) in a large general hospital. Methods: A total number of 2676 V/Q scans of in- and out-patients referred to our department between March 1992 and December 1998 and between April 1997 and December 1998 were analyzed by an identical group of nuclear physicians. Results: Neither the total number of annually performed V/Q scans (446 ± 135) nor the mean age of patients (56 years ± 17) changed significantly since the introduction of HCT. However, the referral pattern was different. The percentage of patients with high and intermediate probability for PE decreased significantly from 15.2% to 9.4% (p < 0.01) and from 10.2% to 7.3% (p < 0.05), respectively. Low probability scans significantly increased from 37.8% to 42.7% (p < 0.05). The percentage of normal scans did not change significantly, however, there was a highly significant increase summarizing patients with normal and low probability scans (74.6% to 83.3%; p < 0.01). Conclusion: The introduction of HCT affected the selection of patients referred for V/Q lung scanning since V/Q scanning was primarily used to exclude rather to confirm PE.

scholarly journals Genetic gains for heat tolerance in potato in three cycles of recurrent selection

2011 ◽  
Vol 11 (2) ◽  
pp. 133-140 ◽  
Author(s):  
Flávio Rodrigo Gandolfi Benites ◽  
César Augusto Brasil Pereira Pinto
Keyword(s):  
Heat Tolerance ◽  
Recurrent Selection ◽  
Base Population ◽  
Genetic Gains ◽  
Growing Seasons ◽  
Second Growth ◽  
Tropical Conditions ◽  
Tuber Traits ◽  
Selection For ◽  
Tuber Specific Gravity

Practically all potato cultivars grown in Brazil are native to Europe and not fully adapted to the tropical conditions. The purpose of this study was to estimate the genetic gains of three cycles of recurrent selection for heat tolerance in potato. The base population in this study consisted of five Brazilian and five heat-tolerant clones. In the winter of 2006 and rainy growing season of 2007 103 clones were evaluated (eight clones of the base population, 29 of the first cycle, 32 and 30 of the second and third recurrent selection cycle, respectively, and four control cultivars). The genetic gains for tuber traits in both growing seasons were 37.8 % (yield), 13.0 % (weight), 32.4 % (percent of large tubers), 0.8 % (tuber specific gravity) and 16.6 % (general tuber appearance). The percentage of physiological disorders (second-growth tubers and cracking) was also reduced by selection.

Selection of extremes

1972 ◽  
Vol 14 (1) ◽  
pp. 11-15 ◽  
Author(s):  
Hans Abplanalp
Keyword(s):  
Selection For ◽  
Selection Intensities ◽  
Efficiency Of Selection ◽  
Culling Level ◽  
Selection Of

SUMMARYA method of selection for two or more traits is investigated, where the selected individuals have to be the highest performing for any one trait, but not necessarily for several traits. The efficiency of selection of extremes is contrasted with the methods of culling levels and tandem selection. It is shown to be superior to culling level selection when the proportion of individuals retained for breeding exceeds 0·5. At higher selection intensities, the effectiveness of selection of extremes falls between that of culling levels and tandem selection.

EARLY GENERATION SELECTION FOR PROTEIN IN Glycine max × G. soja CROSSES

1981 ◽  
Vol 61 (4) ◽  
pp. 901-908 ◽  
Author(s):  
L. R. ERICKSON ◽  
W. D. BEVERSDORF ◽  
H. D. VOLDENG
Keyword(s):  
Protein Content ◽  
Seed Protein ◽  
Glycine Soja ◽  
Mass Selection ◽  
Seed Protein Content ◽  
Family Selection ◽  
Early Generation ◽  
Early Generation Selection ◽  
The Mean ◽  
Selection For

Early generation selection for high seed-protein content would be desirable in breeding programs attempting to combine high yield and high protein content in soybeans (Gycine max (L.) Merr.). The heritability of seed-protein content in the F2 and F3 was measured in four crosses and mass and family selection for protein were compared in the F3 of these crosses. Glycine soja Sieb. and Zucc., a putative wild ancestor of the soybean, was the male parent in all crosses and selection intensity was at 10%. The heritability of protein in the F2, calculated by parent-offspring regression, was 27%. The broad-sense heritability of protein in F3 families grown over two locations in one season was 78%. Mean protein content for every selected population was greater (P ≤ 0.01) than the mean for the non-selected control population (45.3%). Mean protein contents of the F4 populations resulting from these selection methods were: mass selection in the F2 and F3, 48.0%; mass selection in the F3 following one generation of single seed descent, 48.8%; selection among F3 families, 47.6%; selection among and within F3 families, 47.5%. Either method of mass selection was superior to either method of family selection at the 0.01 level. Although early selection (mass or family) raised the mean protein content of a population, segregation continued to give rise to low-protein genotypes thereby requiring further selection.

The challenge of genetic selection for heat tolerance: the dairy cattle example

2016 ◽  
Vol 7 (2) ◽  
pp. 218-222 ◽  
Author(s):  
M. J. Carabaño
Keyword(s):  
Milk Production ◽  
Heat Tolerance ◽  
Genetic Selection ◽  
High Heat ◽  
Temperate Climate ◽  
Environment Interaction ◽  
Heat Tolerant ◽  
Selection For ◽  
Heat Loads ◽  
Selection Of

Exposure of livestock to high heat loads negatively affects animal’s productivity. Genetic selection for heat tolerance using quantitative approaches has been developed by making use of the milk recording information merged with the meteorological information in the test date. The main conclusions of the studies following this approach have been that there is genetic variability in the response to heat stress (HS), that a genotype by environment interaction between thermal comfort and HS conditions exists and that there is a genetic antagonism between HS tolerance and high milk production. This approach has the advantage of adding no extra costs to the existing milk recording schemes, but it has some disadvantages. Current milk recording information does not seem to fully capture the productive response to high heat loads. Moreover, the antagonism between heat tolerance and high milk production may offset the benefits of selection for this trait if heat-tolerant animals are less productive. The use of new tools from phenomics, genomics and transcriptomics can help in achieving an accurate selection of heat-tolerant animals without damaging progress in milk production. New phenotypes for this selection are measure of body temperature and respiration rates together with measures of indicators of heat tolerance in milk, through the use of mid IR spectroscopy. The use of commercial DNA chips to perform genome wide association studies or comparison of whole genome DNA sequence of animals of heat adapted and temperate climate breeds could also provide useful genomic information. Finally, RNA sequencing together with the recent discovery of the possibility to use the milk transcriptome instead of tissue biopsies could help to discover differentially expressed genes under HS and thermoneutrality. The existence of powerful tools to achieve better phenotypes to identify tolerantv. susceptible animals and to gain insights about the genetic mechanisms underlying HS response to be able to disentangle the genetic puzzle of heat tolerance may make possible the selection of heat-tolerant and still productive animals.

scholarly journals Selection intensities of families and clones in potato breeding

2012 ◽  
Vol 36 (1) ◽  
pp. 60-68 ◽  
Author(s):  
César Augusto Ticona Benavente ◽  
César Augusto Brasil Pereira Pinto
Keyword(s):  
Specific Gravity ◽  
Tuber Yield ◽  
Clonal Selection ◽  
Family Selection ◽  
Temperature Conditions ◽  
Sequential Selection ◽  
Clonal Generation ◽  
Selection Intensities ◽  
The Individual ◽  
Selection Of

Families selection has not been recommended as a selection method for vegetative propagated species. To verify its utility for potato improvement a series of experiments were carried out under warm temperatures (rainy season). Thirty clonal families originated from heat tolerant parents were evaluated for tuber yield and specific gravity. After obtaining the seedling generation (SG) and the first clonal generation (FCG) individual clones from a further two generations were assessed. Simulations were conducted with different intensities of family selection in SG and FCG and intensities of clonal selection in subsequent generations. The results show that family selection intensities between 50% and 60% allowed the greatest gains. Estimates of h² at the families level were always higher than at the clones level and corroborate for the more effective selection of families in early generations. The selection of families for tuber specific gravity can be made in the early generations (SG and FCG) regardless of the temperature conditions where the individual clones will be selected. The sequential selection of families with intensities of 60% (SG) and 60% (FCG) would promote greater efficiency for the selection of clones in second or third clonal generation. In the case of applying stronger selection intensities for a higher efficiency with sequential selection (SG and FCG) weaker intensities should be applied in the SG and stronger intensity in FCG . Family selection for tuber yield could be practiced in the FCG as long as the selection of clones was not held in contrasting temperature conditions.

scholarly journals Combinative breeding for large seeds in soybean

2020 ◽  
Vol 115 (2) ◽  
pp. 349
Author(s):  
Galina NAYDENOVA ◽  
Mariana RADKOVA ◽  
Anelia IANTCHEVA
Keyword(s):  
Seed Mass ◽  
Genotypic Diversity ◽  
High Yield ◽  
Additive Variance ◽  
Selection For ◽  
Efficiency Of Selection ◽  
High Degree ◽  
Transgressive Segregations ◽  
Very High ◽  
Selection Of

<p> Technological qualities of the seeds, including their mass, play an important role in the purposeful use of soybean for food production. The purpose of this study is to determine the potential of specific crosses and recombinant lines in the combinative breeding of high yielding large-seeded soybean varieties. During the period of 2018-2019 the F3 and F4 hybride generations of crosses with participation of the ultra-early mature and large-seeded cultivar Romantica were studied. Data were used to evaluate: presence and extent of positive transgressive forms by absolute seed mass in F3 family crosses; genotypic diversity and additive variance at specific crosses; the effectiveness of selection of the trait large seed in F3. According to the results, transgressive selection can be successfully used to reach the goal large seeds in soybean. The efficiency of selection of transgressive forms in F3 generation is high. The genetic potential to combine a high specific mass of seeds with a high yield of seeds per plant has been established for the Romantica cross with the Bulgarian standard variety Srebrina. Recombinant lines suitable for intensive selection for the trait lage seed were obtained from the ‘Romantica’ x ‘Oria’ combination. The ‘Saikai 20’ x ‘Romantica’ cross possess a very high degree of transgressive segregations.</p>

scholarly journals Implications of early selection for resistance to anthracnose in genetic breeding of common bean

2015 ◽  
Vol 15 (3) ◽  
pp. 169-174 ◽  
Author(s):  
José Maria Villela Pádua ◽  
Magno Antonio Patto Ramalho ◽  
Ângela de Fátima Barbosa Abreu
Keyword(s):  
Grain Yield ◽  
Common Bean ◽  
Colletotrichum Lindemuthianum ◽  
Early Selection ◽  
Common Beans ◽  
Selection For ◽  
Pathogen Occurrence ◽  
Efficiency Of Selection ◽  
Segregating Population ◽  
Selection Of

It is questionable if early selection for resistance to Colletotrichum lindemuthianum reduces the efficiency of selection for grain yield in common beans. For this, it was used the segregating population of the cross between two common bean lines: CI107 (susceptible) x BRSMG Madrepérola (resistant). Selection for resistance was carried out in F2and F3, obtaining three types of progenies: not selected (A), selected only in F2(B), and selected in F2and F3(C). The progenies obtained were evaluated for grain yield and pathogen occurrence in experiments. In F3:5, it was used 289 treatments (96 progenies A, 96 B, 95 C and 2 checks (T)); in F3:6, 196 treatments (64 A, 64 B, 64 C and 4 T); in F3:7, 81 treatments (26 A, 26 B, 26 C and 3 T). Selection of plants resistant to anthracnose in early generations increases the successful selection for grain yield in later generations.

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