Screening of melon genotypes for resistance to vegetable leafminer and your phenotypic correlations with colorimetry.

Melon is one of the most important vegetable crops in the world. With short cycle in a system of phased planting, phytosanitary control is compromised, and a great volume of agricultural chemicals is used to control vegetable leafminer. Genetic control is an ideal alternative to avoid the damage caused by this insect. Thus, the aim of this study was to evaluate Cucumis accessions in regard to resistance to leafminer and correlate the variables analyzed. Fifty-four accessions and four commercial hybrids of melon were tested. The study was divided into two experiments: with and with no choice. The following characteristics were evaluated: with choice, in field - subjective score based on the infestation and the number of mines per leaf; and with no choice, in cage - number of mines per leaf, chlorophyll content, and leaf colorimetry. The results showed variability among the accessions and some genotypes showed favorable results for resistance in both experiments. There was correlation between the two variables in the experiment in the field. The accessions CNPH 11-282, CNPH 06-1047, and CNPH 11-1077 are the most recommended for future breeding programs with aim on introgression of resistance to vegetable leafminer in melon.

Screening of melon genotypes for resistance to vegetable leafminer and your phenotypic correlations with colorimetry

ABSTRACT Melon is one of the most important vegetable crops in the world. With short cycle in a system of phased planting, phytosanitary control is compromised, and a great volume of agricultural chemicals is used to control vegetable leafminer. Genetic control is an ideal alternative to avoid the damage caused by this insect. Thus, the aim of this study was to evaluate Cucumis accessions in regard to resistance to leafminer and correlate the variables analyzed. Fifty-four accessions and four commercial hybrids of melon were tested. The study was divided into two experiments: with and with no choice. The following characteristics were evaluated: with choice, in field - subjective score based on the infestation and the number of mines per leaf; and with no choice, in cage - number of mines per leaf, chlorophyll content, and leaf colorimetry. The results showed variability among the accessions and some genotypes showed favorable results for resistance in both experiments. There was correlation between the two variables in the experiment in the field. The accessions CNPH 11-282, CNPH 06-1047, and CNPH 11-1077 are the most recommended for future breeding programs with aim on introgression of resistance to vegetable leafminer in melon.

Seed reserve composition and mobilization during germination and early seedling establishment of Cereus jamacaru D.C. ssp. jamacaru (Cactaceae).

Cereus jamacaru, a Cactaceae found throughout northeast Brazil, is widely used as cattle food and as an ornamental and medicinal plant. However, there has been little information about the physiological and biochemical aspects involved in its germination. The aim of this study was to investigate its reserve mobilization during germination and early seedling growth. For this, C. jamacaru seeds were germinated in a growth chamber and collected at 0, 2, 4, 5, 6, 8 and 12 days after imbibition for morphological and biochemical analyses. Dry seeds had wrinkled seed coats and large, curved embryos. Lipids were the most abundant reserve, comprising approximately 55% and 65% of the dry mass for cotyledons and the hypocotylradicle axis, respectively. Soluble sugars and starch were the minor reserves, corresponding to approximately 2.2% of the cotyledons' dry mass, although their levels showed significant changes during germination. Soluble proteins corresponded to 40% of the cotyledons' dry mass, which was reduced by 81% at the final period of germination compared to dry seeds. C. jamacaru seed can be classified as an oil seed due to its high lipid content. Moreover, lipids were the main reserve mobilized during germination because their levels were strongly reduced after seed germination, while proteins were the second most utilized reserve in this process.

Cereus jamacaru seed germination and initial seedling establishment as a function of light and temperature conditions

Cereus jamacaru is a widespread Cactaceae of northeast Brazil, largely used as cattle food, and as ornamental and medicinal plant. Despite its distinguished importance, until now, there has been little information about the physiological aspects involved on its germination. The objective of this study was to evaluate the effect of light and temperature interaction on the seed germination and seedling establishment of this plant. The evaluated variables were germination percentage at 7 (% G7) and at 14 days after imbibition (% G14), germination average time index (GSI), germination average time (GAT), germination accumulated frequency (GAF), seedling dry mass and height. The highest % G14 and GSI were at 25 ºC in white light, whereas the highest GAT values were in darkness for all evaluated temperatures. On the other hand, % G14, GSI and GAF had the lowest values in darkness. Seeds germinated even in darkness, being however stimulated by the presence of light. The combination of white light and temperature of 25 or 30 °C is the most appropriate condition for seed germination tests.

Cereus jamacaru seed germination and initial seedling establishment as a function of light and temperature conditions

Cereus jamacaru is a widespread Cactaceae of northeast Brazil, largely used as cattle food, and as ornamental and medicinal plant. Despite its distinguished importance, until now, there has been little information about the physiological aspects involved on its germination. The objective of this study was to evaluate the effect of light and temperature interaction on the seed germination and seedling establishment of this plant. The evaluated variables were germination percentage at 7 (% G7) and at 14 days after imbibition (% G14), germination average time index (GSI), germination average time (GAT), germination accumulated frequency (GAF), seedling dry mass and height. The highest % G14 and GSI were at 25 ºC in white light, whereas the highest GAT values were in darkness for all evaluated temperatures. On the other hand, % G14, GSI and GAF had the lowest values in darkness. Seeds germinated even in darkness, being however stimulated by the presence of light. The combination of white light and temperature of 25 or 30 °C is the most appropriate condition for seed germination tests.

Influence of season, harvest time and drying on Java citronella (Cymbopogon winterianus Jowitt) volatile oil

Java citronella (Cymbopogon winterianus Jowitt) is member of the Poaceae family. Java citronella volatile oil has been reported to be among the volatile oils, showing repellent, antimycotic, and acaricide activities. It has been known that agronomical factors have a great effect on both the quality and quantity of essential metabolites. For this reason, it is necessary to determine optimum levels of agronomical factors affecting plant growth and production. Harvest time and drying are very important agronomical factors. This study has been conducted in the Research farm of the " Universidade Federal de Sergipe" , Agronomical Engineering Department along 2002-2003 on the base of factorial experiment in randomized complete block design with three replications. Java citronella was cultivated in a 60 x 60 cm space. Early, midday, and late harvest at 9:00 h, 12:00 h, and 15:00 h were conducted on four different seasons. Fresh and dried leaves were used on the experiments. In order to study the effects of harvest time and drying, yields of dry and fresh herbage (kg/ha), moisture content ( percent), volatile oil content ( percent) and yield (L/ha), and chemical composition of the volatile oil were measured. Seasonal changes had significant effect on yield of fresh herbage, yield and volatile oil content. Maximum volatile oil yields were observed at 9:00 during summer, winter, and spring. Volatile oil content was influenced by season and drying, but not influenced by harvest time.

Citronela de Java (Cymbopogon winterianus Jowitt) pertence à família Poaceae. Óleo volátil de citronela de Java apresenta atividade repelente, antimicrobiana e acaricida. Sabe-se que fatores agronômicos têm grande efeito sobre a qualidade e quantidade de metabólitos essenciais. Por isso é importante a determinação dos níveis ótimos dos fatores agronômicos que afetem o crescimento e a produção. Horário de colheita e secagem são fatores agronômicos muito importantes. O presente estudo foi conduzido na Fazenda Experimental do Departamento de Engenharia Agronômica da Universidade Federal de Sergipe, no período de 2002-2003, usando o delineamento de blocos casualizados e um experimento em esquema fatorial com três repetições. O capim citronela foi cultivado usando espaçamento de 60 cm entre linhas e 60 cm entre plantas. Realizaram-se colheitas de manhã, meio dia e à tarde, às 9:00 h, 12:00 h e 15:00 h, nas quatro estações do ano. Usaram-se folhas frescas e secas no experimento. Para estudar os efeitos do horário de colheita e secagem avaliaram-se as seguintes características: rendimento de biomassa seca e fresca (kg/ha), umidade ( por cento), teor ( por cento) e rendimento (L/ha) de óleo essencial, e a composição química do óleo essencial. Mudanças sazonais apresentaram efeito significativo sobre o rendimento de biomassa fresca e seca, e teor e rendimento de óleo. Rendimentos máximos de óleo essencial foram observados às 9:00 h durante o verão, inverno e primavera. O teor de óleo essencial foi influenciado pela estação doa ano e secagem, mas não foi influenciado pelo horário de colheita.

EFEITO DE CITOCININA E AUXINAS SOBRE O ESTABELECIMEMTO IN VITRO DE Gerbera jamesonii Bolus ex Hook cv. Appelbloesem A PARTIR DE CAPÍTULOS JOVENS

An in vitro method was developed for the establishment and regeneration of larger numbers of uniform plants from the basal parts of the flower of Gerbera jamesonii. The culture medium was MS (MURASHIGE & SKOOG, 1962) solidified with 0.7% agar and supplemented with adenine (80mg/l), tyrosine (100mg/l) and different concentrations and combinations of BAP (6-benzylaminopurine) with IAA (indoleacetic acid), and IAA with 2.4-D (2.4-dichlorophenoxyacetic). Multiple shoot buds formation is observed from capitulum on MS medium incorporate with 3, 6, and 9mg/l of BAP. At 3mg/l of BAP two shoot bud formation per explant are regenerate, at 6mg/l of BAP three shoots and at 9mg/l of BAP just one. 2.4-D is not necessary at this stage of culture establishment.

Na obtenção de plântulas in vitro da cv. Appelbloesem, foram utilizados capítulos jovens como explantes iniciais sendo culturados em meio MS (MURASHIGE & SKOOG, 1962) solidificado com 0,7% de ágar e suplementado com adenina (80mg/l), tirosina (100mg/l) e diferentes concentrações e combinações de BAP (6-benzilaminopurina) com AIA (ácido indole-3-acético) e AIA com 2,4-D (ácido 2,4-diclorofenoxiacético). A avaliação foi feita levando-se em consideração o número de brotos adventícios regenerados por explante, formação de calos e desenvolvimento dos capítulos estabelecidos in vitro. Conseguiu-se melhores resultados com os níveis de 3, 6 e 9mg/l de BAP, sendo que para o nível de 3mg/l de BAP regenerou-se em média, duas brotações por explante, para o nível de 6mg/l de BAP, três brotações e para o nível de 9mg/l, uma brotação. O uso do 2,4-D induz maior formação de calos para a fase de estabelecimento da cultura.

EFEITO DE CITOCININA E AUXINAS SOBRE O ESTABELECIMEMTO IN VITRO DE Gerbera jamesonii Bolus ex Hook cv. Appelbloesem A PARTIR DE CAPÍTULOS JOVENS

An in vitro method was developed for the establishment and regeneration of larger numbers of uniform plants from the basal parts of the flower of Gerbera jamesonii. The culture medium was MS (MURASHIGE & SKOOG, 1962) solidified with 0.7% agar and supplemented with adenine (80mg/l), tyrosine (100mg/l) and different concentrations and combinations of BAP (6-benzylaminopurine) with IAA (indoleacetic acid), and IAA with 2.4-D (2.4-dichlorophenoxyacetic). Multiple shoot buds formation is observed from capitulum on MS medium incorporate with 3, 6, and 9mg/l of BAP. At 3mg/l of BAP two shoot bud formation per explant are regenerate, at 6mg/l of BAP three shoots and at 9mg/l of BAP just one. 2.4-D is not necessary at this stage of culture establishment.

Na obtenção de plântulas in vitro da cv. Appelbloesem, foram utilizados capítulos jovens como explantes iniciais sendo culturados em meio MS (MURASHIGE & SKOOG, 1962) solidificado com 0,7% de ágar e suplementado com adenina (80mg/l), tirosina (100mg/l) e diferentes concentrações e combinações de BAP (6-benzilaminopurina) com AIA (ácido indole-3-acético) e AIA com 2,4-D (ácido 2,4-diclorofenoxiacético). A avaliação foi feita levando-se em consideração o número de brotos adventícios regenerados por explante, formação de calos e desenvolvimento dos capítulos estabelecidos in vitro. Conseguiu-se melhores resultados com os níveis de 3, 6 e 9mg/l de BAP, sendo que para o nível de 3mg/l de BAP regenerou-se em média, duas brotações por explante, para o nível de 6mg/l de BAP, três brotações e para o nível de 9mg/l, uma brotação. O uso do 2,4-D induz maior formação de calos para a fase de estabelecimento da cultura.