Detecção molecular e análise filogenética da sequência parcial do gene da proteína do capsídeo do vírus da faixa das nervuras do morangueiro

O morango cultivado (Fragaria x ananassa Duch. (Rosaceae) é um híbrido originado pelo cruzamento das espécies americanas Fragaria chiloensis e Fragaria virginiana e pertence à família Rosaceae. O morangueiro possui reprodução vegetativa e, por isso, é comum o acúmulo de viroses e outras doenças de difícil controle. Uma das quatro viroses mais importantes na cultura do morango é causada pelo vírus da faixa das nervuras (Strawberry vein banding virus – SVBV), que é transmitido no campo por afídeos, de maneira semipersistente. Para melhorar o conhecimento genômico, são recomendadas técnicas moleculares e a classificação de isolados de SVBV. Um dos determinantes primários da transmissibilidade e especificidade por afídeos é a proteína do capsídeo, que possui importância crítica para o estabelecimento da infecção. Neste trabalho, foi sequenciada parcialmente a proteína do capsídeo do gene do SVBV de um isolado alemão, inoculado em morangueiros e mantido em casa de vegetação no Brasil, por mais de dez anos. Foi realizada a análise filogenética comparando as sequências contidas no GenBank com o objetivo de elucidar as relações evolutivas nesta espécie. As análises filogenéticas mostraram que a sequência do isolado está mais próxima dos isolados dos EUA e Egito. Estes resultados contribuem para a melhor elucidação dos mecanismos de evolução do vírus e do patossistema em questão.

Молекулярно-генетический анализ отборных и элитных форм земляники по генам резистентности Rpf1 и Rca2

Исследования проведены в 2019 – 2020 гг. в Тамбовской области. В качестве биологических объектов использованы перспективные отборные и элитные формы земляники садовой селекции Федерального научного центра им. И. В. Мичурина. Показаны результаты молекулярно-генетического анализа отборных и элитных форм земляники по генам устойчивости к фитофторозному увяданию Rpf1 и антракнозу Rca2. Маркер SCAR-R1A, сцепленный с геном Rpf1, выявлен у форм 62-41 (Былинная × Фейерверк), 69-29 (Фейерверк × Былинная) (предполагаемый генотип по гену устойчивости — Rpf1rpf1). Маркер STS-Rca2_240, сцепленный с геном Rca2, выявлен у отборной формы 933-4 (Fragaria virginiana Duch. ssp. platypetala × Рубиновый кулон) (предполагаемый генотип по гену устойчивости — Rca2rca2). У остальных изученных генотипов земляники маркеры SCAR-R1A и STS-Rca2_240 не выявлены (предполагаемый генотип по локусам устойчивости — rpf1rpf1rca2rca2). Для получения перспективных форм земляники садовой, совмещающих в генотипе гены устойчивости к антракнозной чёрной гнили (Rca2) и фитофторозному увяданию (Rpf1), необходимо дальнейшее проведение целенаправленной селекционной работы с привлечением в гибридизацию идентифицированных источников целевых аллелей генов резистентности.

Evaluation of Various Sources of Viral Infection in Strawberry Fields of Quebec, Canada

The decline of cultivated strawberry (Fragaria × ananassa Duchesne ex Rozier; Rosaceae) observed in the province of Quebec, Canada, between 2012 and 2014 was mostly caused by persistent viruses: strawberry mild yellow edge virus (SMYEV) (Potexvirus; Alphaflexiviridae) and strawberry crinkle virus (SCV) (Cytorhabdovirus; Rhabdoviridae); and semi-persistent viruses: strawberry mottle virus (SmoV) (Secoviridae), strawberry vein banding virus (SVBV) (Caulimovirus; Caulimoviridae), and strawberry pallidosis virus (SPaV) (Crinivirus: Closteroviridae) transmitted by insect vectors. The objective of this study was to determine the sources of viral contamination in commercial strawberry fields in Quebec. Specifically, we wished to 1) determine the prevalence of persistent viruses in winged strawberry aphid Chaetosiphon fragaefolii (Cockerell) (Hemiptera: Aphididae) specimens captured; 2) determine the prevalence of all viruses in wild strawberry Fragaria virginiana Miller plants near commercial plantings; and 3) evaluate the viral contamination of strawberry transplants obtained from nurseries and tested before and after planting in commercial strawberry fields. Results indicated high percentage (38%) of the aphids (n = 205) and high percentage (67%) of F. virginiana patches (n = 12) were infected by strawberry viruses. Ultimately, our results showed a low percentage (5%) of the plants from various nurseries (n = 56) were infected before planting, whereas a third (29%) of the healthy exposed plants in the fields (n = 96) became rapidly infected by insect vectors within a year of having been planted. This study provides significant insights on the relative importance of the various sources of contamination in Quebec strawberry fields: C. fragaefolii versus F. virginiana versus nurseries versus post-nursery infections through exposure to virus-carrying insects.

QUALITY AND ACCEPTANCE OF SOFT CHEESE MADE OF FRIES HOLLAND MILK WITH ADDED STRAWBERRY (Fragaria virginiana) PASTA DURING 2 WEEKS OF STORAGE

This research aimed to evaluate the effect of added strawberry (Fragaria virginiana) in soft cheese on quality of dry matter), Total Plate Count (TPC) and acceptance of consumer during storage of 2 weeks. This research was conducted in Merch- April 2017 in Animal Science Laboratory and Ilmu Hama dan Penyakit Tanaman (IHPT) Laboratory, Faculty of Agriculture, University of Bengkulu. There were 4 treatments and 4 replication, P0: cheese with 0% strawberry pasta, P1: cheese with 1% strawberry pasta, P2: cheese with 3% strawberry pasta, P3: cheese with 5% strawberry pasta. Variables evaluated were quality and acceptance. Results showed that added strawberry (Fragaria virginiana) pasta showed no significant (P>0.05) effects during storage of 2- 4 weeks on dry matter, the highest TPC was found in cheese with 0% strawberry pasta; while, organoleptic test showed very significant effects (P<0.001) on color, aroma and taste of the cheese, however, it was no significant effects (P>0.05) on texture and acceptance.Keywords :

Identifying Resistance to Crown Rot Caused by Colletotrichum gloeosporioides in Strawberry

Resistance to Colletotrichum crown rot (CCR, caused by Colletotrichum gloeosporioides) among commercial strawberry cultivars is variable, and increasing host resistance is a goal of the strawberry breeding program at the University of Florida. Twenty-eight accessions of Fragaria virginiana and F. chiloensis, the progenitor species of the cultivated strawberry (F. × ananassa), were evaluated for CCR resistance on artificially inoculated plants in a field trial, along with cultivars and breeding selections. Accessions PI 612320, PI 612323, and PI 551736 and selections FL 10-128 and FL 10-129 had no mortality in either of two seasons. The most susceptible genotypes had mortality between 75 and 100%. In a separate growth-chamber evaluation, seven genotypes were inoculated by spraying a spore suspension onto the crown or by injecting the suspension directly into the crown tissues. Mortality was higher using the injection method but the ranking of the genotypes was similar for both methods, indicating that resistance is expressed within crown tissues. Among the seven genotypes, selections FL 10-128 and FL 10-129 had the lowest mortality regardless of inoculation method, illustrating that a high level of resistance can be found within the cultivated germplasm.

Characterization of Fragaria virginiana and F. chiloensis in a Minimal-chill, Winter Annual Production System

Wild Fragaria supercore accessions from the U.S. Department of Agriculture (USDA) National Plant Germplasm System collection have been evaluated in temperate climates; however, there have been no characterizations of supercore accessions in non-temperate climates or in annualized production systems. Because Florida can serve as a model system for annualized winter and spring production worldwide, the objective of this study was to characterize an elite group of wild strawberry accessions under field and high tunnel production systems for mortality and the phenological responses of flowering and runner production. The wild accessions along with cultivars were planted in open-field and high tunnel production environments in a randomized complete block design within each environment with raised beds serving as blocks. Four replications of five-plant plots were planted in each of two environments in 2 separate years. With the exception of Darrow 72, F. chiloensis accessions did not perform well in the minimum-chill annualized winter production system. The accessions of this species generally did not flower and were prolific instead in runner production. The F. virginiana accessions performed better with F. virginiana subsps. grayana and virginiana accessions appearing more adapted for minimum-chill winter production because they flowered well and had few runners. We conclude that NC 96-48-1 (PI 612324), NC 95-21-1 (PI 612569), Darrow 72 (PI 236579), and RH 30 (PI 612499) would be attractive for inclusion in germplasm development in a minimal-chill, winter annual production system. In addition to producing many flowers and few runners, these accessions had low mortality.