Ivan dos Santos Pereira

Validation of reference genes for accurate normalization of gene expression for real time-quantitative PCR in strawberry fruits using different cultivars and osmotic stresses☆

The increasing demand of strawberry (Fragaria×ananassa Duch) fruits is associated mainly with their sensorial characteristics and the content of antioxidant compounds. Nevertheless, the strawberry production has been hampered due to its sensitivity to abiotic stresses. Therefore, to understand the molecular mechanisms highlighting stress response is of great importance to enable genetic engineering approaches aiming to improve strawberry tolerance. However, the study of expression of genes in strawberry requires the use of suitable reference genes. In the present study, seven traditional and novel candidate reference genes were evaluated for transcript normalization in fruits of ten strawberry cultivars and two abiotic stresses, using RefFinder, which integrates the four major currently available software programs: geNorm, NormFinder, BestKeeper and the comparative delta-Ct method. The results indicate that the expression stability is dependent on the experimental conditions. The candidate reference gene DBP (DNA binding protein) was considered the most suitable to normalize expression data in samples of strawberry cultivars and under drought stress condition, and the candidate reference gene HISTH4 (histone H4) was the most stable under osmotic stresses and salt stress. The traditional genes GAPDH (glyceraldehyde-3-phosphate dehydrogenase) and 18S (18S ribosomal RNA) were considered the most unstable genes in all conditions. The expression of phenylalanine ammonia lyase (PAL) and 9-cis epoxycarotenoid dioxygenase (NCED1) genes were used to further confirm the validated candidate reference genes, showing that the use of an inappropriate reference gene may induce erroneous results. This study is the first survey on the stability of reference genes in strawberry cultivars and osmotic stresses and provides guidelines to obtain more accurate RT-qPCR results for future breeding efforts.

Produção de amoreira-preta no Brasil

The cultivation of blackberry has grown so intense in recent years. A fact attributed to the increased demand is attributed to several factors, from the economic to the social, which also occurs due to their phytochemical qualities that can bring health benefits, beginning for looking a healthier diet. Moreover, it is a culture whose features, making it a viable option for small properties. The objective of this study was to perform an update article of literature on the culture of blackberry, trying to verify the key management technologies, as well as the needs of the production system and the scenario for the next few years in Brazil.

Bud flower thinning on the reduction of abortion in pear (Pyrus pyrifolia) in Pelotas region

The commercial exploration of the pear culture in Brazil has little expression, due to the low productivity of the plants, being the internal consumption supplied by imports. The lack of adaptation and flower bud abortion, are the main problems for the development of this crop. This work had the objective to evaluate the effect of flower buds thinning on the reduction of the abortion, in Asian cultivars Nijisseiki and Shinseiki. Flower abortion was evaluated at three different times: beginning of the winter (June), spring (September) and end of spring (November) during the year of 2003. The experiment was carried out in a randomized block design with three replicates. The parameter evaluated was the percentage of flower bud abortion. Although the bud thinning has not reduced the abortion indexes in the cultivars, new studies will must be done, being able to, constitute in a cultural practice, trying to reduce the bud floral abortion which intensifies in the winter and in the beginning of the spring, in areas where the chilling hours is insufficient.

Quebra de dormência e cultivo protegidona produção de plantas de mirtileiro

O objetivo deste trabalho foi avaliar o efeito da epoca de aplicacao da cianamida hidrogenada (CH) em tunel baixo e campo aberto, na producao e no desenvolvimento de plantas de mirtileiro. O experimento consistiu na aplicacao de cianamida hidrogenada em quatro epocas (29-06-12, 09-07-12, 19-07-12, 30-07-12) e dois sistemas de cultivo (tunel baixo e campo aberto), alem de um tratamento adicional ou testemunha (sem aplicacao de CH). O delineamento experimental foi em blocos ao acaso, com tres repeticoes, sendo a cultivar utilizada a Powderblue. As variaveis analisadas foram: inicio da floracao, porcentagem de brotacao, comprimento de ramo, massa seca das folhas, teor de clorofila, producao, massa media de frutos, diâmetro medio de frutos, solidos soluveis. A aplicacao de CH em 29-06 e 09-07 antecipou a floracao e a producao. Ja a brotacao foi antecipada quando a CH foi aplicada em 09-07 e 19-07. Em relacao aos sistemas de cultivo, observou-se que o tunel baixo antecipou a floracao e aumentou a producao. Conclui-se que a aplicacao de cianamida hidrogenada, no final de junho/inicio de julho, antecipa o inicio da floracao, da brotacao e da producao, bem como o uso do tunel baixo que antecipa a floracao e aumenta a producao.

Vegetative propagation of raspberry from leafy cuttings

1Agronomist, PhD Student in Agronomy, Plant Breeding, PPGA UFPel. Pelotas-RS, Brazil. E-mail: priscilammarchi@yahoo.com.br 2Agronomist, Dr. in Agronomy, Researcher, Embrapa Temperate Agriculture.Pelotas-RS, Brazil. E-mail: luis.antunes@embrapa.br 3Agronomist, Dr. in Agronomy, Postdoc in Embrapa Temperate Agriculture.Pelotas-RS, Brazil. E-mal: ivanspereira@gmail.com 4Agronomist, PhD student in Agronomy – UFPel. Pelotas-RS, Brazil. E-mail: dani.hohn.sc@gmail.com 5Agronomist, MSc., Researcher, Embrapa Temperate Agriculture.Pelotas-RS, Brazil. E-mail: ricardo.valgas@embrapa.br Abstract The study aimed to evaluate rooting of raspberry cultivars from leafy cuttings in two seasons, autumn and winter. The cultivars Schöenmann, Willamette, Heritage, Polana, Indian Summer, Fall Gold, Golden Bliss and Bababerry were evaluated. Assessments were done 90 days after the installation for both seasons, evaluating the following traits: percentage of cuttings with callus; rooted and live cuttings; the longest root length; and dry mass of roots and sprouting. The results showed that is possible to obtain good rooting rates from leafy cuttings of raspberry cultivars in autumn, and regular in winter. The cultivars Bababerry, Schoenmann and Golden Bliss had higher rooting percentage, followed by Heritage, Polana, Willamette and Fallgold. The cultivar Indian Summer had the lower rooting percentage in autumn and winter.

Genotypic differences in cyanogenic glycosides levels of compatible Prunus persica P. persica and incompatible P. persica P. mume combinations

We acknowledge the Coordination for the Improvement of Higher Education Personnel (CAPES) for their financial support.

Controle do crescimento de mudas de morangueiro Camarosa cultivadas em substrato comercial pela aplicação de Proexadione cálcio

O objetivo do trabalho foi avaliar o efeito do proexadione calcio (ProCa) no controle do crescimento de mudas de morangueiro para producao em substrato comercial. O experimento foi realizado em casa de vegetacao com mudas da cultivar Camarosa produzidas por enraizamento de estoloes e mantidas em bandejas de 72 celulas. Os tratamentos consistiram de sete concentracoes do regulador de crescimento vegetal ProCa (0, 25, 50, 100, 200, 400 e 800 mg L-1). Sendo realizadas avaliacoes de crescimento vegetativo e resposta fisiologica. O delineamento foi inteiramente casualizado com quatro repeticoes de 12 plantas. Observou-se que aplicacoes de doses de ProCa a partir de 200 mg L-1 (200, 400 e 800 mg L-1), reduzem o crescimento vegetativo, assim como, aumentam a concentracao de clorofila e a atividade fotossintetica de mudas de morangueiro ‘Camarosa’