scholarly journals Selection of Heat Tolerant Lettuce (Lactuca sativa L.) Cultivars Grown in Deep Water Culture and Their Marketability

Horticulturae ◽  
2019 ◽  
Vol 5 (3) ◽  
pp. 50 ◽  
Author(s):  
Sydney C. Holmes ◽  
Daniel E. Wells ◽  
Jeremy M. Pickens ◽  
Joseph M. Kemble
Keyword(s):  
Monte Carlo ◽  
Deep Water ◽  
Strongly Correlated ◽  
Warm Climate ◽  
Cool Season ◽  
Water Culture ◽  
Excessive Heat ◽  
Lactuca Sativa L ◽  
Protective Structures ◽  
Selection Of

Lettuce is a cool season vegetable often produced in greenhouses and other protective structures to meet market demands. Greenhouses are being increasingly adopted in warm climate zones where excessive heat often leads to physiological disorders of lettuce, such as tipburn and premature bolting. Greenhouse lettuce growers in warm climates need cultivar recommendations that can help improve production without ignoring marketability. In the current study, eighteen lettuce cultivars were grown in deep water culture and evaluated for growth, bolting, and tipburn in a greenhouse in Auburn, AL, starting on 30 June and 19 August 2016. Based on the severity of bolting and tipburn, nine cultivars were then selected and evaluated on 17 November 2016 for sensory attributes and marketability by 50 untrained consumer panelists. Cultivars ‘Adriana’, ‘Aerostar’, ‘Monte Carlo’, ‘Nevada’, ‘Parris Island’, ‘Salvius’, ‘Skyphos’, and ‘Sparx’ were selected as having higher heat tolerance than cultivars ‘Bambi’, ‘Buttercrunch’ ‘Coastal Star’, ‘Flashy Trout Back’, ‘Green Forest’, ‘Green Towers’, ‘Jericho’, ‘Magenta’, and ‘Truchas’. Higher crispness, lower bitterness, higher overall texture, and higher overall flavor each correlated to higher marketability, regardless of cultivar, but the strongest predictor of marketability was overall flavor. Overall flavor and overall texture were more strongly correlated to marketability than bitterness and crispness, respectively, suggesting that broader sensory categories may better capture human sensory perceptions of lettuce than narrower categories. Cultivars ‘Aerostar’, ‘Monte Carlo’, ‘Nevada’, ‘Parris Island’, ‘Rex’, ‘Salvius’, and ‘Sparx’ performed well in a hot greenhouse and were preferred by consumers. This step-wise experiment could be an adaptable tool for determining highest performing cultivars under any given production constraint, without ignoring marketability.

scholarly journals A look-ahead Monte Carlo simulation method for improving parental selection in trait introgression

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saba Moeinizade ◽  
Ye Han ◽  
Hieu Pham ◽  
Guiping Hu ◽  
Lizhi Wang
Keyword(s):  
Monte Carlo ◽  
State Of The Art ◽  
Simulation Method ◽  
Multiple Trait ◽  
Look Ahead ◽  
Probability Of Success ◽  
Genetic Distribution ◽  
Selection Of ◽  
Trait Introgression

AbstractMultiple trait introgression is the process by which multiple desirable traits are converted from a donor to a recipient cultivar through backcrossing and selfing. The goal of this procedure is to recover all the attributes of the recipient cultivar, with the addition of the specified desirable traits. A crucial step in this process is the selection of parents to form new crosses. In this study, we propose a new selection approach that estimates the genetic distribution of the progeny of backcrosses after multiple generations using information of recombination events. Our objective is to select the most promising individuals for further backcrossing or selfing. To demonstrate the effectiveness of the proposed method, a case study has been conducted using maize data where our method is compared with state-of-the-art approaches. Simulation results suggest that the proposed method, look-ahead Monte Carlo, achieves higher probability of success than existing approaches. Our proposed selection method can assist breeders to efficiently design trait introgression projects.

Aspects of the Use of Den Trees by Arboreal and Scansorial Marsupials Inhabiting Montane Ash Forests in Victoria

1991 ◽  
Vol 39 (1) ◽  
pp. 57 ◽  
Author(s):  
DB Lindenmayer ◽  
RB Cunningham ◽  
MT Tanton ◽  
HA Nix
Keyword(s):  
Metabolic Rate ◽  
Standard Metabolic Rate ◽  
The Body ◽  
Large Species ◽  
Strongly Correlated ◽  
Emergence Time ◽  
Significant Preference ◽  
Field Metabolic Rate ◽  
Arboreal Marsupials ◽  
Selection Of

The time and height of emergence from den trees occupied by various species of arboreal marsupials inhabiting the montane ash forests of the Central Highlands of Victoria, in south-east Australia, were recorded from September 1988 to January 1989. There were significant differences in emergence time among most species of arboreal marsupials. Emergence time was strongly correlated with published values of body weight, field metabolic rate and standard metabolic rate. The entrance to the nest was higher in gliding species than those which are non-volant. Small species exhibited a significant preference for den sites with a hole as the entrance. The entrance of a den occupied by large species was typically a hole in a hollow branch or spout. The selection of den sites was related to the body size of the occupant. Differences in the type and height of the entrance to the nest, together with the time of emergence from the den, indicate partitioning of the nest tree resource between the various species inhabiting montane ash forests.

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