EARLY GENERATION SELECTION UNDER DIFFERENT ENVIRONMENTS AS IT INFLUENCES ADAPTATION OF BARLEY

1967 ◽  
Vol 47 (5) ◽  
pp. 507-517 ◽  
Author(s):  
C. A. St-Pierre ◽  
H. R. Klinck ◽  
F. M. Gauthier
Keyword(s):  
Environmental Conditions ◽  
Early Generation ◽  
Early Generation Selection ◽  
Wide Adaptation ◽  
Segregating Population ◽  
Yield Trials ◽  
Selection Of

Selections, from F2 to F5 inclusive, were made from a segregating population of barley under the environmental conditions of Macdonald College and La Pocatière. In each generation, seed from the selected plants was divided into two parts and subsequently seeded at the two locations. This yearly exchange of material provided 16 selection pathways, that is, groups of different environmental conditions, under which selection was performed. The adaptability of the selected strains was estimated from yield trials conducted at the two stations during F7 and F8. Strains selected at La Pocatière in F4 possessed a better adaptation than those selected at Macdonald College. Strains selected at alternate locations in successive years, starting at La Pocatière in F2, possessed the widest adaptation.Yield trials indicated that the adaptability of the selected strains was dependent upon the selection pathway involved. Selection of barley varieties with wide adaptation could be enhanced by paying attention to the environmental conditions under which the selection is made.

Early generation selection of insect resistance in potato

1984 ◽  
Vol 61 (7) ◽  
pp. 405-418 ◽  
Author(s):  
L. L. Sanford ◽  
T. L. Ladd ◽  
S. L. Sinden ◽  
W. W. Cantelo
Keyword(s):  
Insect Resistance ◽  
Early Generation ◽  
Early Generation Selection ◽  
Selection Of

scholarly journals Aerial High-Throughput Phenotyping Enabling Indirect Selection for Grain Yield at the Early-generation Seed-limited Stages in Breeding Programs

2020 ◽  
Author(s):  
Margaret R. Krause ◽  
Suchismita Mondal ◽  
José Crossa ◽  
Ravi P. Singh ◽  
Francisco Pinto ◽  
...  
Keyword(s):  
Grain Yield ◽  
High Throughput ◽  
Vegetation Indices ◽  
Early Generation ◽  
Breeding Programs ◽  
Breeding Lines ◽  
High Throughput Phenotyping ◽  
Seed Increase ◽  
Yield Trials ◽  
Selection Of

ABSTRACTBreeding programs for wheat and many other crops require one or more generations of seed increase before replicated yield trials can be sown. Extensive phenotyping at this stage of the breeding cycle is challenging due to the small plot size and large number of lines under evaluation. Therefore, breeders typically rely on visual selection of small, unreplicated seed increase plots for the promotion of breeding lines to replicated yield trials. With the development of aerial high-throughput phenotyping technologies, breeders now have the ability to rapidly phenotype thousands of breeding lines for traits that may be useful for indirect selection of grain yield. We evaluated early generation material in the irrigated bread wheat (Triticum aestivum L.) breeding program at the International Maize and Wheat Improvement Center to determine if aerial measurements of vegetation indices assessed on small, unreplicated plots were predictive of grain yield. To test this approach, two sets of 1,008 breeding lines were sown both as replicated yield trials and as small, unreplicated plots during two breeding cycles. Vegetation indices collected with an unmanned aerial vehicle in the small plots were observed to be heritable and moderately correlated with grain yield assessed in replicated yield trials. Furthermore, vegetation indices were more predictive of grain yield than univariate genomic selection, while multi-trait genomic selection approaches that combined genomic information with the aerial phenotypes were found to have the highest predictive abilities overall. A related experiment showed that selection approaches for grain yield based on vegetation indices could be more effective than visual selection; however, selection on the vegetation indices alone would have also driven a directional response in phenology due to confounding between those traits. A restricted selection index was proposed for improving grain yield without affecting the distribution of phenology in the breeding population. The results of these experiments provide a promising outlook for the use of aerial high-throughput phenotyping traits to improve selection at the early-generation seed-limited stage of wheat breeding programs.

Early-Generation Yield Trials of Peanuts1

1974 ◽  
Vol 1 (1) ◽  
pp. 3-6 ◽  
Author(s):  
Terry A. Coffelt ◽  
Ray O. Hammons
Keyword(s):  
Arachis Hypogaea ◽  
Seed Weight ◽  
Breeding Program ◽  
Early Generation ◽  
Breeding Lines ◽  
Early Testing ◽  
Yield Trials ◽  
Selection Of

Abstract In 1969, a large number of F2 lines developed from reciprocal infraspecific crosses between the varieties ‘Argentine’ and ‘Early Runner’ was available for use in the peanut (Arachis hypogaea) breeding program at Tifton, Georgia. These lines were used to make preliminary observations on the possible use of early-generation yield trials in developing superior peanut varieties. High yielding F2 lines were tested consecutively in F3, F4, F5 and F6 yield trials. Lines not out-yielding the parental cultivars were discarded after each test. Lines were placed in F5 and F6 Spanish and Runner yield trials on the basis of seed weight/100 seed. Eight commercial checks were used in the F5 yield trials and five in the F6 yield trials. Yield and shelling grade data from the F5 and F6 yield trials were evaluated statistically. Nine of the twelve breeding lines in the F5 yield trials outylelded the parents. Seven yielded more than the highest yielding commercial check. Two of the five breeding lines in the F6 yield trials did not yield significantly less than the highest yielding commercial check. The remaining three did not yield significantly less than the parental cultivars. Based on these results, early testing in yield trials may be an acceptable breeding procedure for evaluation and selection of peanut varieties.

A rapid method for early generation selection of dwarf genotypes in wheat

Euphytica ◽  
1977 ◽  
Vol 26 (3) ◽  
pp. 733-738 ◽  
Author(s):  
Michael D. Gale ◽  
Richard S. Gregory
Keyword(s):  
Rapid Method ◽  
Early Generation ◽  
Early Generation Selection ◽  
Selection Of

Optimal Offloading Configuration of Spread-Moored FPSOs

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Steven M. Wilkerson ◽  
Satish Nagarajaiah
Keyword(s):  
Environmental Conditions ◽  
Main Tool ◽  
Design Parameters ◽  
Optimization Approach ◽  
Analysis Model ◽  
Simple Analysis ◽  
Formal Approach ◽  
Fine Tune ◽  
Formal Optimization ◽  
Selection Of

As the oil offloading operations of floating production storage and offloading (FPSO) units become more routine, the desire grows to increase the availability for offloading and thus decrease production downtime. Experience with these operations is the main tool available to increase the efficiency of this aspect of deepwater production. However, it is clear that a formal optimization approach can help to fine tune design parameters so that not only is availability increased but the significance of each design parameter can be better understood. The key issue is to define the environmental conditions under which the vessels involved in offloading are able to maintain position. By this, we reduce the notion of availability to a set of operating criteria, which can or cannot be met for a particular set of environmental conditions. The actual operating criteria such as relative vessel heading depend on selection of design parameters, such as the direction and magnitude of external force applied by thrusters or tugs. In the earliest offloading operations, engineering judgment was used to determine the feasibility of offloading at a particular time. For example, if wind and current were not expected to exceed a 1year return period, offloading may be considered safe. This approach can be both conservative and unconservative, depending on the nuances of the particular environmental conditions. This study will propose a formal approach to choosing the design parameters that optimize the availability of a FPSO for offloading. A simple analysis model will be employed so that optimization can be performed quickly using a robust second order method. The proposed analysis model will be compared to model test data to demonstrate its agreement with the more complex system.

scholarly journals Isolated individuals and groups show opposite preferences toward humidity

2018 ◽  
Author(s):  
Mariano Calvo Martín ◽  
Stamatios C. Nicolis ◽  
Isaac Planas-Sitjà ◽  
Jean-Christophe de Biseau ◽  
Jean-Louis Deneubourg
Keyword(s):  
Relative Humidity ◽  
Environmental Conditions ◽  
Group Level ◽  
Individual Level ◽  
Negative Effect ◽  
Multi Level ◽  
The Individual ◽  
Shed Light ◽  
Selection Of

AbstractCockroaches, like most social arthropods, are led to choose collectively among different alternative resting places. These decisions are modulated by different factors, such as environmental conditions (temperature, relative humidity) and sociality (groups size, nature of communications). The aim of this study is to establish the interplay between environmental conditions and the modulation of the interactions between individuals within a group leading to an inversion of preferences. We show that the preferences of isolated cockroaches and groups of 16 individuals, on the selection of the relative humidity of a shelter are inversed and shed light on the mechanisms involved. We suggest that the relative humidity has a multi-level influence on cockroaches, manifested as an attractant effect at the individual level and as a negative effect at the group level, modulating the interactions.

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