Epigenetic insight into floral transition and seed development in plants.

Seasonal changes are crucial in shifting the developmental stages from the vegetative phase to the reproductive phase in plants, enabling them to flower under optimal conditions. Plants grown at different latitudes sense and interpret these seasonal variations, such as changes in day length (photoperiod) and exposure to cold winter temperatures (vernalization). These environmental factors influence the expression of various genes related to flowering. Plants have evolved to stimulate a rapid response to environmental conditions through genetic and epigenetic mechanisms. Multiple epigenetic regulation systems have emerged in plants to interpret environmental signals. During the transition to the flowering phase, changes in gene expression are facilitated by chromatin remodeling and small RNAs interference, particularly in annual and perennial plants. Key flowering regulators, such as FLOWERING LOCUS C (FLC) and FLOWERING LOCUS T (FT), interact with various factors and undergo chromatin remodeling in response to seasonal cues. The Polycomb silencing complex (PRC) controls the expression of flowering-related genes in photoperiodic flowering regulation. Under vernalization-dependent flowering, FLC acts as a potent flowering suppressor by downregulating the gene expression of various flower-promoting genes. Eventually, PRCs are critically involved in the regulation of FLC and FT locus interacting with several key genes in photoperiod and vernalization. Subsequently, PRCs also regulate Epigenetical events during gametogenesis and seed development as a driving force. Furthermore, DNA methylation in the context of CHG, CG, and CHH methylation plays a critical role in embryogenesis. DNA glycosylase DME (DEMETER) is responsible for demethylation during seed development. Thus, the review briefly discusses flowering regulation through light signaling, day length variation, temperature variation and seed development in plants.

Vernalization Requirement, but Not Post-Vernalization Day Length, Conditions Flowering in Carrot (Daucus carota L.).

Carrots require a certain number of cold hours to become vernalized and proceed to the reproductive stage, and this phenomenon is genotype-dependent. Annual carrots require less cold than biennials to flower; however, quantitative variation within annuals and biennials also exists, defining a gradient for vernalization requirement (VR). The flowering response of carrots to day length, after vernalization has occurred, is controversial. This vegetable has been described both as a long-day and a neutral-day species. The objective of this study was to evaluate flowering time and frequency in response to different cold treatments and photoperiod regimes in various carrot genotypes. To this end, three annual genotypes from India, Brazil, and Pakistan, and a biennial carrot from Japan, were exposed to 7.5 °C during 30, 60, 90, or 120 days, and then transferred to either long day (LD) or short day (SD) conditions. Significant variation (p < 0.05) among the carrot genotypes and among cold treatments were found, with increased flowering rates and earlier onset of flowering being associated with longer cold exposures. No significant differences in response to photoperiod were found, suggesting that post-vernalization day length does not influence carrot flowering. These findings will likely impact carrot breeding and production of both root and seed, helping in the selection of adequate genotypes and sowing dates to manage cold exposure and day-length for different production purposes.

Influence of seed vernalization on production, growth and development of lisianthus / Influência da vernalização de semente na produção, crescimento e desenvolvimento de plantas de lisianthus

Flowering induction and control is a limiting factor when commercially producing cut flowers of lisianthus and seed exposure to low temperatures, a physiological event called vernalization, induces the differentiation of vegetative buds to reproductive buds, contributing to a flowering that is uniform and has quality. The objective of this study was to evaluate the influence of seed vernalization in three cultivars of lisianthus (Excalibur, Echo and Mariachi) for 12, 24, 36 and 48 days at temperatures of 5, 10 and 15C, in the production and quality of buds, making this technology feasible to large-scale production. During cultivation it was observed that the lower the temperature and higher the vernalization period, the lower the cycle and the greater the number of plants induced to flowering for all three cultivars, and those are important features in the context of flower production in a commercial scale. The seeds subjected to vernalization originated plants that produce flower stems within the standards required by the market, showing that vernalization was efficient to induce flowering without affecting the quality of the buds. To produce lisianthus as a cut flower of quality, it is recommended seed vernalization of Mariachi and Echo cultivars for 24 days at 5C and Excalibur for 36 days at 5C.(AU)

A indução e controle do florescimento é fator limitante na produção comercial de flores de corte em lisianthus e ocorre pela exposição das sementes a baixas temperaturas, evento fisiológico denominado vernalização, o qual induz a diferenciação das gemas vegetativas em reprodutivas, contribuindo para uma floração uniforme e de qualidade. Assim, o objetivo deste estudo foi avaliar a influência da vernalização de sementes de três variedades de lisianthus (Excalibur, Echo e Mariachi), por 12, 24, 36 e 48 dias, a temperaturas 5, 10 e 15 C, na produção e qualidade das hastes florais e disponibilizar esta tecnologia ao sistema produtivo. Ao longo do cultivo observou-se que quanto menor a temperatura e maior o período de vernalização, menor foi o ciclo e maior foi o número de plantas induzidas ao florescimento, para as três cultivares, características importantes no contexto da produção de flores em escala comercial. As sementes submetidas à vernalização originaram plantas que produziram hastes florais dentro dos padrões exigidos pelo mercado, mostrando que a vernalização foi eficiente no sentido de indução das plantas ao florescimento sem afetar a qualidade das hastes florais. Para o cultivo de plantas de lisianthus como flor de corte de qualidade recomenda-se vernalizar as sementes das cultivares Mariachi e Echo por 24 dias a 5 C e da Excalibur por 36 dias a 5 C.(AU)

Light and temperature cues: multitasking receptors and transcriptional integrators.

Contents Summary 1029 I. Introduction 1029 II. Convergence at the receptor 1030 III. Convergence at transcriptional hubs 1031 IV. Convergence involving clock components 1033 V. Conclusions 1033 Acknowledgements 1033 References 1033 SUMMARY: The combined information provided by light and temperature cues helps to optimise plant body architecture and physiology. Plants possess elaborate systems to sense and respond to these stimuli. Simultaneous perception of light and temperature by dual receptors such as phytochrome B and phototropin leads to immediate signalling convergence. Conversely, cue asynchronies initiate separate pathways and the information of the earliest cue is stored, awaiting the arrival of the later cue to control transcription. Storage mechanisms can involve changes in the activity of selected clock components or epigenetic modifications, depending on the time delay between cues (hours, days or several months). We propose a conceptual framework in which the mechanisms of integration relate to the timing of cue sensing.

Influence of seed vernalization on production, growth and development of lisianthus / Influência da vernalização de semente na produção, crescimento e desenvolvimento de plantas de lisianthus

Flowering induction and control is a limiting factor when commercially producing cut flowers of lisianthus and seed exposure to low temperatures, a physiological event called vernalization, induces the differentiation of vegetative buds to reproductive buds, contributing to a flowering that is uniform and has quality. The objective of this study was to evaluate the influence of seed vernalization in three cultivars of lisianthus (Excalibur, Echo and Mariachi) for 12, 24, 36 and 48 days at temperatures of 5, 10 and 15C, in the production and quality of buds, making this technology feasible to large-scale production. During cultivation it was observed that the lower the temperature and higher the vernalization period, the lower the cycle and the greater the number of plants induced to flowering for all three cultivars, and those are important features in the context of flower production in a commercial scale. The seeds subjected to vernalization originated plants that produce flower stems within the standards required by the market, showing that vernalization was efficient to induce flowering without affecting the quality of the buds. To produce lisianthus as a cut flower of quality, it is recommended seed vernalization of Mariachi and Echo cultivars for 24 days at 5C and Excalibur for 36 days at 5C.

A indução e controle do florescimento é fator limitante na produção comercial de flores de corte em lisianthus e ocorre pela exposição das sementes a baixas temperaturas, evento fisiológico denominado vernalização, o qual induz a diferenciação das gemas vegetativas em reprodutivas, contribuindo para uma floração uniforme e de qualidade. Assim, o objetivo deste estudo foi avaliar a influência da vernalização de sementes de três variedades de lisianthus (Excalibur, Echo e Mariachi), por 12, 24, 36 e 48 dias, a temperaturas 5, 10 e 15 C, na produção e qualidade das hastes florais e disponibilizar esta tecnologia ao sistema produtivo. Ao longo do cultivo observou-se que quanto menor a temperatura e maior o período de vernalização, menor foi o ciclo e maior foi o número de plantas induzidas ao florescimento, para as três cultivares, características importantes no contexto da produção de flores em escala comercial. As sementes submetidas à vernalização originaram plantas que produziram hastes florais dentro dos padrões exigidos pelo mercado, mostrando que a vernalização foi eficiente no sentido de indução das plantas ao florescimento sem afetar a qualidade das hastes florais. Para o cultivo de plantas de lisianthus como flor de corte de qualidade recomenda-se vernalizar as sementes das cultivares Mariachi e Echo por 24 dias a 5 C e da Excalibur por 36 dias a 5 C.

A single haplotype hyposensitive to light and requiring strong vernalization dominates Arabidopsis thaliana populations in Patagonia, Argentina.

The growing collection of sequenced or genotyped Arabidopsis thaliana accessions includes mostly individuals from the native Eurasian and N. African range and introduced North American populations. Here, we describe the genetic and phenotypic diversity, along with habitats and life history, of A. thaliana plants collected at the southernmost end of its worldwide distribution. Seed samples were harvested from plants growing in four sites within a ~3500-km2 -area in Patagonia, Argentina, and represent the first germplasm to be collected in South America for this species. Whole-genome resequencing revealed that plants from the four sites and a Patagonia herbarium specimen collected in 1967 formed a single haplogroup (Pat), indicating that the phenotypic variation observed in the field reflected plastic responses to the environment. admixture and principal components analyses suggest that the ancestor of the Pat haplogroup either came from Italy or the Balkan/Caucasus regions of Eurasia. In the laboratory, plants from the Pat haplogroup were hyposensitive to continuous red (Rc) and shade light, with corresponding changes in the expression of phytochrome signalling genes. Pat had higher PIF3 and PIF5 and lower HY5 expression under Rc light; and lower expression of PIL1, ATHB2 and HFR1 under shade compared to Col-0. In addition, Pat plants had a strong vernalization requirement associated with high levels of FLC expression. We conclude that including Pat in studies of natural variation and in comparison with other introduced populations will provide additional information for association studies and allow for a more detailed assessment of the demographic events following colonization.

Analysis of VRN1 gene in triticale and common wheat genetic background

In cereals, the transition from the vegetative stage to flowering is controlled in the main by the set of vernalization genes. Within these genes the most important role is played by VRN1, which encodes a MADS-box transcription factor, regulating the transition of shoot apical meristem to the reproductive phase. The level of vernalization requirement is strongly linked to the molecular structure of this gene. In this study we analyzed molecular mechanisms regulating the vernalization requirement in triticale on the basis of comparative analysis of the VRN1 locus between triticale (×Triticosecale Witt.) and common wheat (Triticum aestivum L.) genotypes. We also estimated the influence of VRN genotype on heading time and the winter hardiness of these two species. Molecular markers developed for VRN genotype detection in common wheat were successfully applied to an analysis of triticale genomic DNA. Subsequent analysis of the amplicons nucleotide sequence confirmed full similarity of the products obtained between triticale and common wheat. All winter triticale cultivars tested contained the recessive vrn-A1 allele, whereas all spring genotypes carried the dominant Vrn-A1a allele. Molecular analysis of the Vrn-B1 gene revealed the presence of the dominant Vrn-B1b allele in only one of the triticale genotypes analyzed (Legalo). The major system of determination of the vernalization requirement in triticale was transferred from common wheat without changes and is based on an alteration in the VRN1 gene promoter sequence within the A genome.(AU)

Analysis of VRN1 gene in triticale and common wheat genetic background

In cereals, the transition from the vegetative stage to flowering is controlled in the main by the set of vernalization genes. Within these genes the most important role is played by VRN1, which encodes a MADS-box transcription factor, regulating the transition of shoot apical meristem to the reproductive phase. The level of vernalization requirement is strongly linked to the molecular structure of this gene. In this study we analyzed molecular mechanisms regulating the vernalization requirement in triticale on the basis of comparative analysis of the VRN1 locus between triticale (×Triticosecale Witt.) and common wheat (Triticum aestivum L.) genotypes. We also estimated the influence of VRN genotype on heading time and the winter hardiness of these two species. Molecular markers developed for VRN genotype detection in common wheat were successfully applied to an analysis of triticale genomic DNA. Subsequent analysis of the amplicons nucleotide sequence confirmed full similarity of the products obtained between triticale and common wheat. All winter triticale cultivars tested contained the recessive vrn-A1 allele, whereas all spring genotypes carried the dominant Vrn-A1a allele. Molecular analysis of the Vrn-B1 gene revealed the presence of the dominant Vrn-B1b allele in only one of the triticale genotypes analyzed (Legalo). The major system of determination of the vernalization requirement in triticale was transferred from common wheat without changes and is based on an alteration in the VRN1 gene promoter sequence within the A genome.

Vernalization and cut of apical third of the bulbs in yield and quality of seeds of onion / Vernalização e corte do terço apical dos bulbos na produção e qualidade de sementes de cebola

The onion (Allium cepa L.) belongs to the family Alliaceae, and the second vegetables in economic importance. It horticultural culture of high relevance, in central-south and in the far south, is highlighting the states of Sao Paulo, Rio Grande do Sul, Santa Catarina and Parana. The bulbificacion only begins when the combination of the determinants of bulbificacion (photoperiod and temperature) of each cultivar is reached. It Can be grown in tropical regions with the use of vernalization of the bulbs. The objective of this study is to identify the efficiency in the production of seed, onion depending on the cut or not the bulb before the period of vernalization. The analysis of the variables consisted: humidity; number of seeds; mass of seeds for umbel; umbels number; number of seeds for umbel; total number of flowers and of fecundated flowers; number of seeds for capsule; total mass of seeds; emergency percentage; vigor percentage; index of emergency speed and mass of 100 seeds humidity; number of seeds; mass of seeds for umbel; umbels number; number of seeds for umbel; total number of flowers and of fecundated flowers; number of seeds for capsule; total mass of seeds; emergency percentage; vigor percentage; index of emergency speed and mass of 100 seeds, using the cultivars Baia Periforme and Texas Grano. The experimental design was randomized blocks with four replicates, the

A cebola (Allium cepa L.) pertence à família Alliaceae, sendo a segunda hortaliça em importância econômica. É cultura oleracea de alta relevância no centro-sul e no extremo sul, destacando-se os estados de São Paulo, Rio Grande do Sul, Santa Catarina e Paraná. A bulbificação apenas se inicia quando a combinação dos fatores determinantes (fotoperíodo e temperatura) de cada cultivar é atingida. Contudo, pode ser cultivada em regiões tropicais com o uso da vernalização dos bulbos. O objetivo deste trabalho é identificar a eficiência na produção de semente de cebola em função do corte ou não dos bulbos submetidos a vernalização. As análises consistiram das variáveis: umidade; número de sementes; massa de sementes por umbela; número de umbelas; número de sementes por umbela; número total de flores e de flores fecundadas; número de sementes por cápsula; massa total de sementes; porcentagem de emergência de plântulas; primeira contagem do teste de germinação, índice de velocidade de emergência e massa de 100 sementes, utilizando as cultivares Baia Periforme e Texas Grano. O delineamento experimental foi de blocos casualizados com quatro repetições, constando 80 plantas por repetição, cada parcela foi conduzida com 20 plantas distribuídas em 4 linhas com 5 plantas com espaçamento de 20cm entre plantas e entre linhas as quais foram avaliadas as 6 plantas centrais. A produção de sementes

Vernalization and cut of apical third of the bulbs in yield and quality of seeds of onion / Vernalização e corte do terço apical dos bulbos na produção e qualidade de sementes de cebola

The onion (Allium cepa L.) belongs to the family Alliaceae, and the second vegetables in economic importance. It horticultural culture of high relevance, in central-south and in the far south, is highlighting the states of Sao Paulo, Rio Grande do Sul, Santa Catarina and Parana. The bulbificacion only begins when the combination of the determinants of bulbificacion (photoperiod and temperature) of each cultivar is reached. It Can be grown in tropical regions with the use of vernalization of the bulbs. The objective of this study is to identify the efficiency in the production of seed, onion depending on the cut or not the bulb before the period of vernalization. The analysis of the variables consisted: humidity; number of seeds; mass of seeds for umbel; umbels number; number of seeds for umbel; total number of flowers and of fecundated flowers; number of seeds for capsule; total mass of seeds; emergency percentage; vigor percentage; index of emergency speed and mass of 100 seeds humidity; number of seeds; mass of seeds for umbel; umbels number; number of seeds for umbel; total number of flowers and of fecundated flowers; number of seeds for capsule; total mass of seeds; emergency percentage; vigor percentage; index of emergency speed and mass of 100 seeds, using the cultivars Baia Periforme and Texas Grano. The experimental design was randomized blocks with four replicates, the

A cebola (Allium cepa L.) pertence à família Alliaceae, sendo a segunda hortaliça em importância econômica. É cultura oleracea de alta relevância no centro-sul e no extremo sul, destacando-se os estados de São Paulo, Rio Grande do Sul, Santa Catarina e Paraná. A bulbificação apenas se inicia quando a combinação dos fatores determinantes (fotoperíodo e temperatura) de cada cultivar é atingida. Contudo, pode ser cultivada em regiões tropicais com o uso da vernalização dos bulbos. O objetivo deste trabalho é identificar a eficiência na produção de semente de cebola em função do corte ou não dos bulbos submetidos a vernalização. As análises consistiram das variáveis: umidade; número de sementes; massa de sementes por umbela; número de umbelas; número de sementes por umbela; número total de flores e de flores fecundadas; número de sementes por cápsula; massa total de sementes; porcentagem de emergência de plântulas; primeira contagem do teste de germinação, índice de velocidade de emergência e massa de 100 sementes, utilizando as cultivares Baia Periforme e Texas Grano. O delineamento experimental foi de blocos casualizados com quatro repetições, constando 80 plantas por repetição, cada parcela foi conduzida com 20 plantas distribuídas em 4 linhas com 5 plantas com espaçamento de 20cm entre plantas e entre linhas as quais foram avaliadas as 6 plantas centrais. A produção de sementes

Produtividade de alho vernalizado em função de fontes e doses de fósforo / Productivity of vernalized garlic in function of sources and doses of phosphorous

Objetivou-se com este trabalho verificar a influência de fontes e doses de fósforo na produtividade do alho vernalizado (cv. 'Roxo Pérola de Caçador') em solo com baixo teor de fósforo. O experimento foi conduzido em condições de campo no Setor de Olericultura da Universidade Federal de Lavras. Foram avaliadas três fontes de P (superfosfato simples, com 18 por cento de P2O5; superfosfato triplo, com 41 por cento de P2O5 e termofosfato magnesiano, com 17 por cento de P2O5), três doses (200, 400 e 600kg ha-1 de P2O5) e um tratamento adicional, que não recebeu adubação fosfatada. A aplicação de 200kg ha-1 de P2O5, utilizando como fonte o superfosfato triplo, proporcionou maior ganho em fitomassa total de plantas e melhores resultados com relação à produtividade de bulbos comerciais.

The objective of this research was to verify the influence of sources and doses of phosphorus in the productivity of vernalized garlic in soil with low phosphorus content. The experiment was carried out in field conditions in the Horticulture Sector at the Universidade Federal de Lavras. Three sources (simple superphosphate, with 18 percent of P2O5; triple superphosphate, with 41 percent of P2O5 and magnesium term phosphate, with 17 percent of P2O5), three doses (200, 400 e 600kg ha-1 de P2O5), and one additional treatment, that didn't receive manuring with phosphorus were tested. The application of 200kg ha-1 of P2O5, using triple superphosphate provides the best profit in total mass of plants and productivity of commercial bulbs.

Allelic variation at the Vrn-A1, Vrn-B1, Vrn-D1, Vrn-B3 and Ppd-D1a loci of Pakistani spring wheat cultivars

Flowering time in bread wheat (Triticum aestivum L.) is controlled by vernalization and photoperiod response, and earliness per se genes. The genetic basis of flowering time has not been investigated in Pakistani bread wheat. This study was, therefore, conducted to determine the allelic composition at Vrn-A1, Vrn-B1, Vrn-D1, Vrn-B3 and Ppd-D1a loci of 59 Pakistani spring bread wheat cultivars. These cultivars, along with 4 isogenic lines for vernalization genes were characterized with previously reported DNA markers designed for detecting allelic variation at 4 Vrn (Vernalization) and 1 Ppd (Photoperiod) loci. Spring habit Vrn-A1a allele was found in 36 percent cultivars either alone or with spring habit Vrn-B1 and Vrn-D1 alleles. Two wheat cultivars had the dominant Vrn-A1c allele, whereas none of the cultivars had Vrn-A1b. Spring habit Vrn-B1 was the most frequent allele (64 percent) present either alone or with Vrn-A1a, Vrn-A1c and Vrn-D1. Spring habit Vrn-D1 was found in 61 percent cultivars. Vrn-D1 was singly found in 25 percent cultivars and along with Vrn-B1 in 29 percent cultivars. Dominant Vrn-B3 was absent in all cultivars studied. All cultivars except Era had the photoperiod insensitive allele Ppd-D1a. We did not find any association between the flowering time and Vrn allelic composition of the studied cultivars. This indicated that the partial vernalization requirement of cultivars with Vrn-B1 and Vrn-D1 alleles is probably fulfilled during Pakistani growing season. Earliness per se and the photoperiod sensitive loci other than Ppd-D1 need to be investigated to further understand the genetic basis of flowering time in Pakistani wheat.

Produtividade de alho vernalizado em função de fontes e doses de fósforo

The objective of this research was to verify the influence of sources and doses of phosphorus in the productivity of vernalized garlic in soil with low phosphorus content. The experiment was carried out in field conditions in the Horticulture Sector at the Universidade Federal de Lavras. Three sources (simple superphosphate, with 18% of P2O5; triple superphosphate, with 41% of P2O5 and magnesium term phosphate, with 17% of P2O5), three doses (200, 400 e 600kg ha-1 de P2O5), and one additional treatment, that didn't receive manuring with phosphorus were tested. The application of 200kg ha-1 of P2O5, using triple superphosphate provides the best profit in total mass of plants and productivity of commercial bulbs.

Objetivou-se com este trabalho verificar a influência de fontes e doses de fósforo na produtividade do alho vernalizado (cv. 'Roxo Pérola de Caçador') em solo com baixo teor de fósforo. O experimento foi conduzido em condições de campo no Setor de Olericultura da Universidade Federal de Lavras. Foram avaliadas três fontes de P (superfosfato simples, com 18% de P2O5; superfosfato triplo, com 41% de P2O5 e termofosfato magnesiano, com 17% de P2O5), três doses (200, 400 e 600kg ha-1 de P2O5) e um tratamento adicional, que não recebeu adubação fosfatada. A aplicação de 200kg ha-1 de P2O5, utilizando como fonte o superfosfato triplo, proporcionou maior ganho em fitomassa total de plantas e melhores resultados com relação à produtividade de bulbos comerciais.

Produtividade de alho vernalizado em função de fontes e doses de fósforo

The objective of this research was to verify the influence of sources and doses of phosphorus in the productivity of vernalized garlic in soil with low phosphorus content. The experiment was carried out in field conditions in the Horticulture Sector at the Universidade Federal de Lavras. Three sources (simple superphosphate, with 18% of P2O5; triple superphosphate, with 41% of P2O5 and magnesium term phosphate, with 17% of P2O5), three doses (200, 400 e 600kg ha-1 de P2O5), and one additional treatment, that didn't receive manuring with phosphorus were tested. The application of 200kg ha-1 of P2O5, using triple superphosphate provides the best profit in total mass of plants and productivity of commercial bulbs.

Objetivou-se com este trabalho verificar a influência de fontes e doses de fósforo na produtividade do alho vernalizado (cv. 'Roxo Pérola de Caçador') em solo com baixo teor de fósforo. O experimento foi conduzido em condições de campo no Setor de Olericultura da Universidade Federal de Lavras. Foram avaliadas três fontes de P (superfosfato simples, com 18% de P2O5; superfosfato triplo, com 41% de P2O5 e termofosfato magnesiano, com 17% de P2O5), três doses (200, 400 e 600kg ha-1 de P2O5) e um tratamento adicional, que não recebeu adubação fosfatada. A aplicação de 200kg ha-1 de P2O5, utilizando como fonte o superfosfato triplo, proporcionou maior ganho em fitomassa total de plantas e melhores resultados com relação à produtividade de bulbos comerciais.

Vernalização afeta a mobilização de reservas de açúcares e nitrogênio e a emergência de plantas de lírio (Lilium longiflorum thunb.) ‘snow queen

In order to evaluate the response of effective vernalization days on the soluble sugar and total nitrogen contents and the emergence of Lilium longiflorum plant shoots, cv ‘Snow Queen bulbs were kept under different vernalization temperatures and periods of treatment under vernalizing temperatures, and cultivated in a plastic greenhouse after the vernalization. The experiment was carried out at the Universidade Federal de Santa Maria, RS, in two seasons: from 03/20/02 to 11/05/02 and from 12/05/02 to 05/15/03. The treatments were 0, 9, 11, 14, 19, 23, 28, 29, 34, 38, 42, 45 and 56 effective vernalization days, calculated with a beta response function to temperature. The soluble sugar and total nitrogen contents, and the duration of the planting-emergence (P-M) phase were determined. The vernalization promoted the mobilization of sugar and nitrogen reserves, which is important for the nutrition of the emergence of the shoot. The increasing number of the effective vernalization days reduced the duration of the P-E phase. Bulbs treated under temperatures of 10ºC for 6 to 8 weeks of storage (34 and 45DV), had the shortest duration of the P-E phase.

Com o objetivo de avaliar a resposta dos dias efetivos de vernalização do lírio sobre o conteúdo de açúcares solúveis e nitrogênio total e a emergência de plantas, bulbos de Lilium longiflorum, cv ‘Snow Queen foram submetidos a diferentes temperaturas de vernalização e períodos de exposição à temperaturas vernalizantes e cultivados em estufa plástica. O experimento foi conduzido na Universidade Federal de Santa Maria, Santa Maria (RS), em duas épocas de plantio dos bulbos: de 20/03/02 a 05/11/02 e 05/12/02 a 15/05/03. Os tratamentos foram 0, 9, 11, 14, 19, 23, 28, 29, 34, 38, 42, 45 e 56 dias efetivos de vernalização (DV), calculados a partir de uma função beta de resposta da vernalização à temperatura. Determinaram-se o conteúdo de açúcares solúveis e nitrogênio total e a duração do subperíodo de plantio dos bulbos-emergência das plantas (P-E). A vernalização promoveu a mobilização de reservas de açúcares e nitrogênio, o que é importante para nutrição da planta em emergência. O aumento do número de dias efetivos de vernalização reduziu a duração do subperíodo P-E. Bulbos tratados em temperaturas de 10ºC por 6 e 8 semanas de armazenamento (34 e 45DV), apresentaram uma menor duração do subperíodo P-E.

Vernalização afeta a mobilização de reservas de açúcares e nitrogênio e a emergência de plantas de lírio (Lilium longiflorum thunb.) ‘snow queen’

In order to evaluate the response of effective vernalization days on the soluble sugar and total nitrogen contents and the emergence of Lilium longiflorum plant shoots, cv ‘Snow Queen’ bulbs were kept under different vernalization temperatures and periods of treatment under vernalizing temperatures, and cultivated in a plastic greenhouse after the vernalization. The experiment was carried out at the Universidade Federal de Santa Maria, RS, in two seasons: from 03/20/02 to 11/05/02 and from 12/05/02 to 05/15/03. The treatments were 0, 9, 11, 14, 19, 23, 28, 29, 34, 38, 42, 45 and 56 effective vernalization days, calculated with a beta response function to temperature. The soluble sugar and total nitrogen contents, and the duration of the planting-emergence (P-M) phase were determined. The vernalization promoted the mobilization of sugar and nitrogen reserves, which is important for the nutrition of the emergence of the shoot. The increasing number of the effective vernalization days reduced the duration of the P-E phase. Bulbs treated under temperatures of 10ºC for 6 to 8 weeks of storage (34 and 45DV), had the shortest duration of the P-E phase.

Com o objetivo de avaliar a resposta dos dias efetivos de vernalização do lírio sobre o conteúdo de açúcares solúveis e nitrogênio total e a emergência de plantas, bulbos de Lilium longiflorum, cv ‘Snow Queen’ foram submetidos a diferentes temperaturas de vernalização e períodos de exposição à temperaturas vernalizantes e cultivados em estufa plástica. O experimento foi conduzido na Universidade Federal de Santa Maria, Santa Maria (RS), em duas épocas de plantio dos bulbos: de 20/03/02 a 05/11/02 e 05/12/02 a 15/05/03. Os tratamentos foram 0, 9, 11, 14, 19, 23, 28, 29, 34, 38, 42, 45 e 56 dias efetivos de vernalização (DV), calculados a partir de uma função beta de resposta da vernalização à temperatura. Determinaram-se o conteúdo de açúcares solúveis e nitrogênio total e a duração do subperíodo de plantio dos bulbos-emergência das plantas (P-E). A vernalização promoveu a mobilização de reservas de açúcares e nitrogênio, o que é importante para nutrição da planta em emergência. O aumento do número de dias efetivos de vernalização reduziu a duração do subperíodo P-E. Bulbos tratados em temperaturas de 10ºC por 6 e 8 semanas de armazenamento (34 e 45DV), apresentaram uma menor duração do subperíodo P-E.