Hochelaga lettuce

2008 ◽  
Vol 88 (3) ◽  
pp. 551-553 ◽  
Author(s):  
Sylvie Jenni ◽  
George C Emery
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Organic Soil ◽  
Organic Soils ◽  
Physiological Disorder ◽  
Long Day ◽  
Lactuca Sativa L ◽  
Lettuce Breeding ◽  
Growing Conditions ◽  
Horticultural Research

Hochelaga is an early and heavy crisphead lettuce highly tolerant to bolting under long-day growing conditions (more than 13-h). Hochelaga is the first variety released by the Horticultural Research and Development Centre (HRDC) lettuce breeding program of Agriculture and Agri-Food Canada (AAFC), Saint-Jean-sur-Richelieu, Quebec. Very similar in appearance to Ithaca, the regional standard, Hochelaga is well adapted to organic soils. Hochelaga is more tolerant than Ithaca to rib discoloration, a physiological disorder caused by high-temperature growing conditions. Key words: Lactuca sativa L., crisphead lettuce, rib discoloration, bolting, heat stress, organic soil

scholarly journals Estival lettuce

2009 ◽  
Vol 89 (1) ◽  
pp. 99-101 ◽  
Author(s):  
Sylvie Jenni ◽  
George C Emery
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Research And Development ◽  
Organic Soil ◽  
Organic Soils ◽  
Physiological Disorder ◽  
Long Day ◽  
Lettuce Breeding ◽  
Growing Conditions ◽  
Horticultural Research

Estival is a heavy crisphead lettuce highly tolerant to bolting under long day growing conditions (more than 13 h). Estival is the first Vanguard-type lettuce released by the Horticultural Research and Development Centre (HRDC) lettuce breeding program of Agriculture and Agri-Food Canada (AAFC), Saint-Jean-sur-Richelieu, Quebec. Very similar in appearance to Summertime, Estival is well adapted to organic soils. Estival is more tolerant than Ithaca (the regional standard) or Summertime to rib discoloration, a physiological disorder caused by high-temperature growing conditions. Key words: Lactuca sativa, crisphead lettuce, rib discoloration, bolting, tipburn, heat stress, organic soil

scholarly journals Protein and Starch Content of 20 Wheat (Triticum aestivum L.) Genotypes Exposed to High Temperature Under Late Sowing Conditions

2012 ◽  
Vol 4 (2) ◽  
pp. 477 ◽  
Author(s):  
M. A. Hakim ◽  
A. Hossain ◽  
Jaime A. Teixeira da Silva ◽  
V. P. Zvolinsky ◽  
M. M. Khan
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Starch Content ◽  
High Temperature Stress ◽  
Yield Reduction ◽  
Days To Heading ◽  
Growing Conditions ◽  
Genotype E ◽  
Late Sowing ◽  
Percentage Protein

A total of 20 spring wheat genotypes were evaluated under three growing conditions (optimum, late and very late) at the research farm of the Wheat Research Center, Bangladesh to assess the variation in grain yield, protein and starch content under heat stress. All genotypes were significantly affected by high temperature stress in late and very late sowing conditions, resulting in a decrease in days to heading and maturity, ultimately affecting yield, protein and starch content. Considering yield performance, genotype ‘E-8’ was best under optimum (6245 kg ha-1), late (5220 kg ha-1) and very late sowing (4657 kg ha-1) conditions while ‘E-40’ was the worst. With respect to yield reduction, genotype ‘E-72’ was heat-tolerant (13% yield reduction) while ‘Prodip’ (49% yield reduction) was heat-susceptible. On the other hand, it was found that the percentage protein increased as heat stress increased. Under heat stress, genotype ‘E-65’ and ‘E-60’ had the highest and lowest protein content (15.5% and 12%), respectively. With respect to starch content, ‘Prodip’ and ‘E-37’ had the highest while ‘E-14’ and ‘E-72’ had the lowest content (64.8% vs. 62.9%), respectively in all sowing conditions. Keywords: Yield; Protein; Starch; Wheat. © 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v4i2.8679 J. Sci. Res. 4 (2), 477-489 (2012)

scholarly journals Response of Tomato Genotypes under Different High Temperatures in Field and Greenhouse Conditions

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 449
Author(s):  
Sophoanrith Ro ◽  
Leangsrun Chea ◽  
Sreymey Ngoun ◽  
Zachary P. Stewart ◽  
Siranet Roeurn ◽  
...  
Keyword(s):  
Temperature Field ◽  
Heat Stress ◽  
High Temperature ◽  
Heat Tolerance ◽  
Fruit Yield ◽  
Growth And Yield ◽  
Optimal Temperature ◽  
Fruit Setting ◽  
Growing Conditions ◽  
Tomato Genotypes

Heat stress is one of the production constraints for tomato (Solanum lycopersicum L.) due to unfavorable, above optimum temperatures. This research was undertaken to evaluate growth and fruit yield of tomato genotypes under three contrasting growing conditions (i.e., optimal temperature in field-, high temperature in field- and high temperature in greenhouse conditions) to determine their relative heat tolerance. Eleven tomato genotypes, including two local check varieties, were evaluated, and data on growth and yield were measured and analyzed. The interactions between the genotypes and growing conditions for all yield traits were significant. In general, the performance of tomato under optimal temperature field conditions was better than under high temperature field- and greenhouse conditions. Genotypes CLN1621L, CLN2026D, CLN3212C, and KK1 had consistently greater fruit yield per plant in all growing conditions. Although the local genotype, Neang Tamm, had lower yield under optimal conditions, it performed moderately well under high temperature field- and high temperature greenhouse conditions, and yield decrease under high temperature condition was minimal. Genotype CLN1621L had stable fruit setting compared to other genotypes under high temperature conditions. Since fruit setting and yield are important traits for heat tolerance, genotypes CLN1621L and Neang Tamm are potential candidates for breeding programs focused on improved yield and heat stress tolerance.

Effect of Irradiance Level and Paclobutrazol on Reducation of Leaf Damage in Begonia × cheimantha

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 446d-446
Author(s):  
Beyounghan Yoon ◽  
Harvey J. Lang
Keyword(s):  
Day Treatment ◽  
Leaf Damage ◽  
Growth Retardants ◽  
Damage Development ◽  
Long Day ◽  
Leaf Chlorosis ◽  
Shade Cloth ◽  
Growing Conditions ◽  
Reduced Light ◽  
Shade Plants

Begonia × cheimantha (Christmas or Lorraine begonia) is a popular holiday crop in Europe, with certain cultivars having outstanding postharvest characteristics. Its commercial production in the southern United States has been limited by the occurrence of mottled leaf chlorosis and necrosis, apparently due to environmental stress. In this study, B. × cheimantha `Emma' was grown in the fall in a glass greenhouse at College Station, Texas, under either 0%, 60%, or 87% polyethylene shade cloth. Leaf chlorosis and necrosis was very severe on plants grown in full sun (≈650 mol·m–2·s–1), with slight chlorosis on plants under 60% shade. Plants under full sun, however, were more compact, flowered earlier, and had shorter peduncles with more flowers than those grown under shade. Reducing the vegetative long-day treatment period from 7 to 4 weeks had no effect on leaf damage development. Plants treated with paclobutrazol were shorter and had less leaf damage than untreated plants. Leaves of treated plants had a relatively higher concentration of soluble protein, chlorophyll, and enhanced activities of ascorbate peroxidase (AsA), dehydroascorbate (DHA) reductase, and monodehydro-ascorbate (MDHA) reductase than untreated plants. For Texas growing conditions, these preliminary studies indicate that B. × cheimantha should be grown under reduced light intensities, with excessive height and leaf damage being controlled with growth retardants such as paclobutrazol.

scholarly journals GERMINATION AND VIGOUR IN SEEDS OF THE COWPEA IN RESPONSE TO SALT AND HEAT STRESS

2019 ◽  
Vol 32 (1) ◽  
pp. 143-151 ◽  
Author(s):  
Luma Rayane de Lima Nunes ◽  
Paloma Rayane Pinheiro ◽  
Charles Lobo Pinheiro ◽  
Kelly Andressa Peres Lima ◽  
Alek Sandro Dutra
Keyword(s):  
Salt Stress ◽  
Heat Stress ◽  
High Temperature ◽  
Low Temperature ◽  
Vigna Unguiculata ◽  
Salt Concentration ◽  
Dry Weight ◽  
Germination Percentage ◽  
Different Types ◽  
Different Temperatures

ABSTRACT Salinity is prejudicial to plant development, causing different types of damage to species, or even between genotypes of the same species, with the effects being aggravated when combined with other types of stress, such as heat stress. The aim of this study was to evaluate the tolerance of cowpea genotypes (Vigna unguiculata L. Walp.) to salt stress at different temperatures. Seeds of the Pujante, Epace 10 and Marataoã genotypes were placed on paper rolls (Germitest®) moistened with different salt concentrations of 0.0 (control), 1.5, 3.0, 4.5 and 6.0 dS m-1, and placed in a germination chamber (BOD) at temperatures of 20, 25, 30 and 35°C. The experiment was conducted in a completely randomised design, in a 3 × 4 × 5 scheme of subdivided plots, with four replications per treatment. The variables under analysis were germination percentage, first germination count, shoot and root length, and total seedling dry weight. At temperatures of 30 and 35°C, increases in the salt concentration were more damaging to germination in the Epace 10 and Pujante genotypes, while for the Marataoã genotype, damage occurred at the temperature of 20°C. At 25°C, germination and vigour in the genotypes were higher, with the Pujante genotype proving to be more tolerant to salt stress, whereas Epace 10 and Marataoã were more tolerant to high temperatures. Germination in the cowpea genotypes was more sensitive to salt stress when subjected to heat stress caused by the low temperature of 20°C or high temperature of 35°C.

scholarly journals Wheat (Triticum aestivum L.) TaHMW1D Transcript Variants Are Highly Expressed in Response to Heat Stress and in Grains Located in Distal Part of the Spike

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 687
Author(s):  
Chan Seop Ko ◽  
Jin-Baek Kim ◽  
Min Jeong Hong ◽  
Yong Weon Seo
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Temperature Stress ◽  
Storage Proteins ◽  
Seed Storage ◽  
Seed Storage Proteins ◽  
Grain Filling ◽  
High Temperature Stress ◽  
Two Dimensional Gel Electrophoresis ◽  
Transcript Variants

High-temperature stress during the grain filling stage has a deleterious effect on grain yield and end-use quality. Plants undergo various transcriptional events of protein complexity as defensive responses to various stressors. The “Keumgang” wheat cultivar was subjected to high-temperature stress for 6 and 10 days beginning 9 days after anthesis, then two-dimensional gel electrophoresis (2DE) and peptide analyses were performed. Spots showing decreased contents in stressed plants were shown to have strong similarities with a high-molecular glutenin gene, TraesCS1D02G317301 (TaHMW1D). QRT-PCR results confirmed that TaHMW1D was expressed in its full form and in the form of four different transcript variants. These events always occurred between repetitive regions at specific deletion sites (5′-CAA (Glutamine) GG/TG (Glycine) or (Valine)-3′, 5′-GGG (Glycine) CAA (Glutamine) -3′) in an exonic region. Heat stress led to a significant increase in the expression of the transcript variants. This was most evident in the distal parts of the spike. Considering the importance of high-molecular weight glutenin subunits of seed storage proteins, stressed plants might choose shorter polypeptides while retaining glutenin function, thus maintaining the expression of glutenin motifs and conserved sites.

RELATIONSHIPS BETWEEN SOME PROPERTIES OF ORGANIC SOILS FROM THE SOUTHERN CANADIAN SHIELD

1990 ◽  
Vol 70 (3) ◽  
pp. 363-377 ◽  
Author(s):  
D. ANN BROWN ◽  
S. P. MATHUR ◽  
ANTON BROWN ◽  
D. J. KUSHNER
Keyword(s):  
Principal Component Analysis ◽  
Acid Leaching ◽  
Principal Component ◽  
Organic Soil ◽  
Component Analysis ◽  
Soil Types ◽  
Organic Soils ◽  
Mining Districts ◽  
Two Populations ◽  
Inorganic Components

Different numerical methods used to distinguish between organic soil types are evaluated. The research was initiated by the suggestion that acid leaching from mining wastes could be prevented by capping the tailings with a self-renewing methane-producing muskeg bog, in order to prevent the penetration of oxygen to the wastes. Thirty organic soils from bogs in the mining districts of Elliot Lake, Sudbury, and Timmins, Ontario, and Noranda, Quebec, were sampled and 28 soil characteristics were measured. These characteristics, whose values are normally or lognormally distributed, were analyzed by several different statistical methods. Some characteristics indicate the existence of two populations, and others are bivariantly correlated. Canonical discriminant analysis was more successful than cluster analysis in separating the bogs into well-defined geographical groups. However, principal component analysis proved best at grouping the organic soils according to their organic and inorganic components, and we suggest that this is a suitable method for the general discrimination of organic soil types. Methane was present in all the 17 bogs tested for it, and in two very wet bogs more than 2 mmol of methane per liter were extracted. Key words: Muskeg bog, organic soils, soil characterization, principal component analysis

Pre-anthesis high-temperature acclimation alleviates damage to the flag leaf caused by post-anthesis heat stress in wheat

2011 ◽  
Vol 168 (6) ◽  
pp. 585-593 ◽  
Author(s):  
Xiao Wang ◽  
Jian Cai ◽  
Dong Jiang ◽  
Fulai Liu ◽  
Tingbo Dai ◽  
...  
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Flag Leaf ◽  
Temperature Acclimation

Host choice, settling and folding leaf behaviors of the larval rice leaf folder under heat stress

2016 ◽  
Vol 106 (6) ◽  
pp. 809-817 ◽  
Author(s):  
M.A. Bodlah ◽  
A.-X. Zhu ◽  
X.-D. Liu
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Host Choice ◽  
Cnaphalocrocis Medinalis ◽  
Behavioral Traits ◽  
The Third ◽  
Rice Leaf ◽  
Rice Leaf Folder ◽  
Extreme High Temperature ◽  
Third Instar Larvae

AbstractExtreme high-temperature events are the key factor to determine population dynamics of the rice leaf folder,Cnaphalocrocis medinalis(Guenée), in summer. Although we know that adult of this insect can migrate to avoid heat stress, the behavioral response of larva to high temperature is still unclear. Therefore, impacts of high temperature on behavioral traits ofC. medinalisincluding host choice, settling and folding leaf were observed. The results revealed that these behavioral traits were clearly influenced by high temperature. The larvae preferred maize leaves rather than rice and wheat at normal temperature of 27°C, but larvae experienced a higher temperature of 37 or 40°C for 4 h preferred rice leaves rather than maize and wheat. Capacity of young larvae to find host leaves or settle on the upper surface of leaves significantly reduced when they were treated by high temperature. High temperature of 40°C reduced the leaf-folding capacity of the third instar larvae, but no effects were observed on the fourth and fifth instar larvae. Short-term heat acclimation could not improve the capacity of the third instar larvae to make leaf fold under 40°C.

scholarly journals High temperatures during microsporogenesis fatally shorten pollen lifespan

2021 ◽  
Author(s):  
Maurizio Iovane ◽  
Giovanna Aronne
Keyword(s):  
Experimental Data ◽  
Heat Treatment ◽  
Heat Stress ◽  
High Temperature ◽  
Male Gametophyte ◽  
Crop Productivity ◽  
Anther Dehiscence ◽  
Optimal Temperature ◽  
Drastic Reduction ◽  
Crop Species

AbstractMany crop species are cultivated to produce seeds and/or fruits and therefore need reproductive success to occur. Previous studies proved that high temperature on mature pollen at anther dehiscence reduce viability and germinability therefore decreasing crop productivity. We hypothesized that high temperature might affect pollen functionality even if the heat treatment is exerted only during the microsporogenesis. Experimental data on Solanum lycopersicum ‘Micro-Tom’ confirmed our hypothesis. Microsporogenesis successfully occurred at both high (30 °C) and optimal (22 °C) temperature. After the anthesis, viability and germinability of the pollen developed at optimal temperature gradually decreased and the reduction was slightly higher when pollen was incubated at 30 °C. Conversely, temperature effect was eagerly enhanced in pollen developed at high temperature. In this case, a drastic reduction of viability and a drop-off to zero of germinability occurred not only when pollen was incubated at 30 °C but also at 22 °C. Further ontogenetic analyses disclosed that high temperature significantly speeded-up the microsporogenesis and the early microgametogenesis (from vacuolated stage to bi-cellular pollen); therefore, gametophytes result already senescent at flower anthesis. Our work contributes to unravel the effects of heat stress on pollen revealing that high temperature conditions during microsporogenesis prime a fatal shortening of the male gametophyte lifespan.

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