A new economical storage technique for strawberry (Fragaria × ananassa Duch.) in vitro

Strawberry plants grown in vitro are typically stored and maintained on agar containing Murashige and Skoog (MS) media and sucrose as a carbohydrate source. This method of storing strawberry plants in vitro is expensive and time consuming, requiring sub-culturing onto fresh media every 2 to 3 mo. This study aimed to establish the viability of using a substrate alternative as an economical replacement for MS media, for both long-term storage in vitro and ease of transfer (ex vitro). A protocol was developed for strawberry in vitro using commercially available sterilized peat pellets (Jiffy-7® pellets), to optimize culture conditions and tissue culture practices. Suitability of the peat substrate was measured by the plant’s overall response to culture in vitro and subsequent health and survival ex vitro following deflasking. Included in this study was a comparison of the use of vented vs non-vented tissue culture vessels for their effect on plant development and survival in vitro and ex vitro. The results show that strawberry plants can be grown and stored under in vitro conditions in vented vessels without sub-culturing for up to 3 yr or more. This equates to an approximately eightfold more efficient technique, significantly decreasing cost of storing and maintaining strawberry plants in vitro. Furthermore, plants grown in the peat substrate did not multiply, and had more established secondary roots than those grown in the conventional MS media

An Examination of Middle School Students’ Attitudes Toward Science

For more than 40 years, researchers have been studying the persistent underrepresentation of women in science. Today, the gender gap has narrowed in some, but not all, disciplines of science. To better understand the impetus of this continuing problem, the attitudes of middle school students toward science were examined using a causal-comparative design based on biological sex across four attitude constructs: attitudes toward school science, desire to become a scientist, value of science to society, and perceptions of scientists. A sample of 450 sixth-, seventh-, and eighth-grade science students located in suburban, central New Jersey responded to Likert-type items on the My Attitudes Toward Science (MATS) survey during their regularly scheduled science class periods. Data analysis was performed through a multivariate analysis of variance. The findings indicated no statistically significant differences in middle school students’ attitudes toward school science, desire to become a scientist, value of science to society, and perceptions of scientists based on biological sex of the students. Implications for the findings are discussed

A new economical storage technique for strawberry (Fragaria × ananassa Duch.) in vitro

Strawberry plants grown in vitro are typically stored and maintained on agar containing Murashige and Skoog (MS) media and sucrose as a carbohydrate source. This method of storing strawberry plants in vitro is expensive and time consuming, requiring sub-culturing onto fresh media every 2 to 3 mo. This study aimed to establish the viability of using a substrate alternative as an economical replacement for MS media, for both long-term storage in vitro and ease of transfer (ex vitro). A protocol was developed for strawberry in vitro using commercially available sterilized peat pellets (Jiffy-7® pellets), to optimize culture conditions and tissue culture practices. Suitability of the peat substrate was measured by the plant’s overall response to culture in vitro and subsequent health and survival ex vitro following deflasking. Included in this study was a comparison of the use of vented vs non-vented tissue culture vessels for their effect on plant development and survival in vitro and ex vitro. The results show that strawberry plants can be grown and stored under in vitro conditions in vented vessels without sub-culturing for up to 3 yr or more. This equates to an approximately eightfold more efficient technique, significantly decreasing cost of storing and maintaining strawberry plants in vitro. Furthermore, plants grown in the peat substrate did not multiply, and had more established secondary roots than those grown in the conventional MS media

Resistance to Fusarium oxysporum f. sp fragariae and Predicted Breeding Values in Strawberry

Fusarium wilt of strawberry, incited by Fusarium oxysporum f. sp. fragariae (Fof), is a major disease of the cultivated strawberry (Fragaria xananassa) worldwide. An increase in disease outbreaks of the pathogen in Western Australia and Queensland plus the search for alternative disease management strategies place emphasis on the development of resistant cultivars. In response, a partial incomplete diallel cross involving four parents was performed for use in glasshouse resistance screenings. The resulting progeny were evaluated for their susceptibility to Fof. Best-performing progeny and suitability of progenies as parents were determined using data from disease severity ratings and analyzed using a linear mixed model incorporating a pedigree to produce best linear unbiased predictions of breeding values. Variation in disease response, ranging from highly susceptible to resistant, indicates a quantitative effect. The estimate of the narrow-sense heritability was 0.49 +/- 0.04 (SE), suggesting the population should be responsive to phenotypic recurrent selection. Several progeny genotypes have predicted breeding values higher than any of the parents. Knowledge of Fof resistance derived from this study can help select best parents for future crosses for the development of new strawberry cultivars with Fof resistance

Resistance to Fusarium oxysporum f. sp fragariae and Predicted Breeding Values in Strawberry

Fusarium wilt of strawberry, incited by Fusarium oxysporum f. sp. fragariae (Fof), is a major disease of the cultivated strawberry (Fragaria xananassa) worldwide. An increase in disease outbreaks of the pathogen in Western Australia and Queensland plus the search for alternative disease management strategies place emphasis on the development of resistant cultivars. In response, a partial incomplete diallel cross involving four parents was performed for use in glasshouse resistance screenings. The resulting progeny were evaluated for their susceptibility to Fof. Best-performing progeny and suitability of progenies as parents were determined using data from disease severity ratings and analyzed using a linear mixed model incorporating a pedigree to produce best linear unbiased predictions of breeding values. Variation in disease response, ranging from highly susceptible to resistant, indicates a quantitative effect. The estimate of the narrow-sense heritability was 0.49 +/- 0.04 (SE), suggesting the population should be responsive to phenotypic recurrent selection. Several progeny genotypes have predicted breeding values higher than any of the parents. Knowledge of Fof resistance derived from this study can help select best parents for future crosses for the development of new strawberry cultivars with Fof resistance