Germination temperatures affect the physiological quality of seeds of lettuce cultivars

Almeida, Fernandes Antônio de; Silva-Mann, Renata; Santos, Heloísa Oliveira dos; Pereira, Rucyan Walace; Blank, Arie Fitzgerald

doi:10.14393/bj-v35n4a2019-42196

Cited by 4 publications

(1 citation statement)

References 19 publications

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“…Sowing was performed in April and harvest in October. Seeds of the Everglades cultivar considered tolerant to thermoinhibition (Almeida et al, 2019), 'Verônica'', considered sensitive to thermoinhibition (Kano et al, 2011;Villela et al, 2010) and 'Luisa', which shows intermediate tolerance to thermoinhibition (Catão et al, 2014;Villela et al, 2010) were sown in polypropylene trays filled with commercial substrate for vegetables to obtain the seedlings.…”

Section: Methodsmentioning

confidence: 99%

Enviromental temperature and age of seeds in tolerance to thermoinhibition in lettuce genotypes1

et al. 2023

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Lettuce seeds usually show germination problems that can be related to dormancy and or thermoinhibition, as well as to the genotype constitution. The knowledge of the temperature at which the thermoinhibition process begins, as well as the influence of the age of the seed on its germination, is extremely important to establish more suitable parameters for the selection of higher genotypes in breeding programs. The objective of this work was to evaluate the seed germination of three lettuce cultivars according to the enviromental temperature and the age of the seeds. The cultivars Everglades (tolerant to thermoinhibition), Luisa (medium tolerant) and Verônica (sensitive) were used. Seeds of each cultivar were evaluated by the standard germination test, first count test, germination speed index and germination test of remaining seeds. The analyses were performed at four environmental temperatures and in seven storage periods after harvest. None of the cultivars showed primary dormancy. The tolerance to thermoinhibition showed by cultivars Everglades and Luisa and the sensitivity of cultivar Verônica were confirmed. The most suitable temperature for differentiating tolerant and sensitive thermoinhibition genotypes occurred from 30.5 ºC and 260 days after harvest.

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Section: Methodsmentioning

confidence: 99%

Enviromental temperature and age of seeds in tolerance to thermoinhibition in lettuce genotypes1

et al. 2023

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Artificial neural networks discriminate lettuce seeds with different levels of thermoinhibition

et al. 2023

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The thermoinhibition of lettuce seed germination causes important losses for producers, who do not have thermotolerant commercial cultivars. One of the obstacles has been the scarcity of optimizing techniques capable of efficiently discriminating thermotolerant and thermosensitive cultivars. The aim of this work was to evaluate the use of neural networks to discriminate different levels of thermoinhibition in lettuce seeds. Seeds of 18 cultivars were evaluated for thermoinhibition considering the characteristics of the first and last germination count and germination speed index, in seeds subjected to temperatures of 20, 25, 30 and 35 °C. The remaining seeds, which did not germinate, were subjected to the tetrazolium test. Analyses were performed immediately after seed harvesting and repeated after six months of storage. Discriminant analysis was performed and the Kohonen’s Self-Organizing Map (SOM) was created using Artificial Neural Networks (ANNs). Neural networks discriminate lettuce cultivars and organizes them in terms of seed thermoinhibition tolerance through Kohonen’s Self-Organizing Map. Discriminant analysis consistently identifies the Everglades and Luiza genotypes as tolerant to thermoinhibition.

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Endo-β-mannanase and superoxide dismutase as enzymatic markers for lettuce seeds thermotolerance

Cavasin,

Santos,

Oliveira

et al. 2023

J. Seed Sci.

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At higher temperatures, lettuce seeds may not germinate, resulting in problems for crop establishment in the field and production. This study aimed to evaluate the maternal effect for thermotolerance on lettuce seeds and find enzymatic markers. We used the thermoinhibition tolerant cultivar ‘Everglades’, the sensitive ‘Verônica’, their reciprocal hybrids, F1 and F2 generation. Seeds were submitted to germination and enzymatic tests (catalase, superoxide dismutase, ascorbate peroxidase, and endo- β-mannanase). Germination (first and final counting) and speed index were compared through Tukey’s test. ‘Everglades’ and its reciprocal hybrids, have not been influenced by temperature regarding germination compared to the other treatments. Also, the maternal effect was observed for the F1 generation. Higher temperatures interfere with the activity of all enzymes evaluated, consequently in the physiological parameters. However, superoxide dismutase and endo- β-mannanase have shown direct and more expressive correlation with changes on the physiological parameters compared to the other enzymes. Thus, it is possible to conclude that those enzymes can be used as markers for thermotolerant genotype selection.

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Germination temperatures affect the physiological quality of seeds of lettuce cultivars

Cited by 4 publications

References 19 publications

Enviromental temperature and age of seeds in tolerance to thermoinhibition in lettuce genotypes1

Enviromental temperature and age of seeds in tolerance to thermoinhibition in lettuce genotypes1

Artificial neural networks discriminate lettuce seeds with different levels of thermoinhibition

Endo-β-mannanase and superoxide dismutase as enzymatic markers for lettuce seeds thermotolerance

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