scholarly journals Simultaneous selection on vegetative and reproductive phenology in a perennial herb

Author(s):  
Elsa Fogelström ◽  
Giulia Zacchello ◽  
Johan Ehrlen

The timing of different life history events are often correlated, and selection might only rarely be exerted independently on the timing of a single event. In plants, phenotypic selection has often been shown to favour earlier flowering. However, little is known about to what extent this selection acts directly vs. indirectly via vegetative phenology, and if selection on the two traits is correlational. We estimated direct, indirect and correlational phenotypic selection on vegetative and reproductive phenology over three years for the perennial herb Lathyrus vernus. Direct selection favoured earlier flowering and shorter timespans between leaf-out and flowering in all years. However, early flowering was associated with early leaf-out, and the direction of selection on leaf-out day varied among years. As a result, selection on leaf-out weakened selection for early flowering in one of the study years. We found no evidence of correlational selection. Our results highlight the importance of including temporally correlated traits when exploring selection on the phenology of seasonal events.

2018 ◽  
Vol 151 (2) ◽  
pp. 209-218 ◽  
Author(s):  
Michael R. Sekor ◽  
Steven J. Franks

Background and aims – Despite the importance of selection in driving evolution, little is known about the consistency of selection, particularly in the early stages of colonization of novel environments. This study examines the targets and consistency of selection on an experimentally introduced population of the annual plant, Brassica rapa L., in its first three years following introduction to a novel environment. Methods – Phenotypic selection analyses were conducted on a variety of traits collected during the first three years following introduction from California to New York, and the consistency of the strength and direction of selection was examined. Key results – The introduced population experienced direct selection for increased overall size and earlier flowering in 2011 and 2012, and increased height, earlier flowering, and longer duration of flowering in 2013. While the direction of selection only varied for height, inter-annual variation in the strength of selection was observed for a variety of traits, possibly due to changing weather patterns in the introduced environment. Conclusions – The results suggest that selection is dynamic and can fluctuate over time. Thus multi-year assessments of selection are useful for predicting evolutionary responses, particularly in the early stages of colonization of a novel environment.


HortScience ◽  
2020 ◽  
Vol 55 (4) ◽  
pp. 400-402
Author(s):  
Felipe Barrera Sánchez ◽  
Larissa Pereira Ribeiro ◽  
Mayara Fávero Cotrim ◽  
Carlos Antonio da Silva Junior ◽  
Leonardo Lopes Bhering ◽  
...  

This study aimed to estimate the predicted genetic gains with the simultaneous selection of yield traits and soluble solids content in cherry tomato hybrids. Twenty cherry tomato hybrids were evaluated in hydroponic cultivation in randomized block design with three replicates. The following traits were evaluated: number of clusters per plant, number of flowers per cluster, number of fruits per cluster, number of fruits per plant, fruit weight, fruit yield per plant, and total soluble solids content. The parameters of heritability, experimental cv, and genotypic cv were estimated. Subsequently, selection gains by direct selection and Mulamba and Mock index were estimated. Direct selection of cherry tomato hybrids for fruit yield and soluble solids content is inefficient because selection based on one of these traits will provide undesirable gains in the other. However, simultaneous selection for yield and taste quality is possible based on the Mulamba and Mock index because the methodology provided high selection gains for both yield and soluble solids content.


HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 967B-967
Author(s):  
Matthew D. Robbins ◽  
Jack E. Staub

Four cucumber (Cucumus sativus L.) inbred lines were intermated then bulked maternally to create four base populations denoted as cycle 0 (i.e., Pop.1 C0, Pop.2 C0, Pop.3 C0, Pop.4 C0). Each of these populations underwent phenotypic selection (PHE; open-field evaluations), selection by marker (MAS; genotyping at 20 marker loci), and random mating (RAN; no selection) for three cycles. The four traits under selection, multiple lateral branching (MLB), gynoecious sex expression (GYN), earliness (EAR), and fruit length to diameter ratio (L:D), are quantitatively inherited, controlled by relatively few (two to six) QTL per trait and are directly related to yield. Using the same C0 populations and selection scheme allowed a direct comparison of the effectiveness of MAS and PHE. Because each C0 population varied for any given trait, the response to MAS and PHE was not the same for each population. In general, C0 populations that were inferior for a trait either responded favorably to selection or remained constant, while those with superior trait values either did not change or decreased. Both MAS and PHE provided improvements in all traits under selection in at least one population, with the exception of MAS for EAR. MAS and PHE were equally effective at improving MLB and L:D, but PHE was generally more effective than MAS for GYN and EAR. When considering all traits, responses to PHE were superior in three of the four populations. The population for which MAS was superior, however, showed the only increase in yield (fruit per plant), which was not under direct selection. These results indicate that both MAS and PHE are useful for multi-trait improvement in cucumber, but their effectiveness depends on the traits and populations under selection.


Confectionery sunflower - a special area of use of sunflower, which requires the creation of marketable seeds quality features. One of the possible ways to create large-fruited sunflower is to create production hybrids and lines. Objective: to evaluate the created new large-fruited sunflower lines by a complex of morphological characters and determine the best lines for use as large-seeds hybrids as parent components or source material. In 2016-2019 years on the basis of the Institute of Oilseed Crops NAAS a study was conducted to assess the economic characteristics of large-fruited sunflower lines. We studied a collection of 27 lines of large-seeds sources. The lines were created by direct selection or crossing and sampling: Reyny of Argentinean origin, Zaporizhzhya confectionery variety, confectionery hybrid with striped pericarp color of Israeli origin, white seed of Turkish origin, synthetic population - donor of complex resistance. To study from the collection, lines were drawn that went through at least 7 generations with selection for seed size. Experience has shown that the shortest growing season for lines 174d and KP11 was 99 days, and the longest for lines I2K670 was 109 days. In the studied collection, the greatest mass of 1000 seeds has the KP11-146.47g line, which is the mother component and does not have branching. The second by weight of 1000 seeds (109 g) stood out line 168v, which also had branches and pollen fertility restoration genes and will be used as the paternal form. The third largest is also one basket line ZKN51-100. The collection included lines originating from the same combination, but with a different morphotype for the presence and absence of branching. So, based on the combination of KP11 x Zaporizhzhya Confectionery, three lines were obtained. A mass of 1000 seeds was observed in 98-86 g, with the branching line having the largest mass of 1000 seeds. The lines created with one combination VK678 x ZKN32: with a branch 168a had a mass of 1000 seeds 95g, and a line 168b - without a branch 109 g. Of the two lines obtained from the descendants of the combination KP11 x the striped hybrid both had branches, but the seeds were much smaller (weight of 1000 seeds 59 and 79 g). The collection also studied samples created on the basis of varieties and populations 160c, 174, 175b, the mass of 1000 seeds of which turned out to be more acceptable for large-fruited use from 83 to 99 g. Summing up the results of studying the collection of newly created lines, we can highlight the lines 162d, 168v, 175b, KP11 that are potentially promising for use in hybrids. The selections showed that large-fruited lines can be obtained from large-fruited varieties, self-pollination of large-fruited hybrids and crossing lines with hybrids and varieties. Self-pollination and selection of large-fruited lines in several generations does not provide the necessary variability for positive changes in selections. The result of the selection by weight of 1000 seeds in the offspring from crosses and from populations creates opportunities for new large-seeds sunflower.


Crop Science ◽  
1986 ◽  
Vol 26 (3) ◽  
pp. 533-536 ◽  
Author(s):  
Clyde C. Berg ◽  
Robert T. Sherwood ◽  
Kenneth E. Zeiders

Sign in / Sign up

Export Citation Format

Share Document