-Aldrich (Shanghai, China). All other chemicals and solvents were of analytical reagent grade and were purchased from Sangon Biotech Co., Ltd (Shanghai, China). Plant materials and experimental treatments. Strawberry ( Fragaria × ananassa Duch. cv. Yueli) plantlets
The main cultivation method of strawberry ( Fragaria × ananassa Duch.) in Japan is forcing culture using June-bearing cultivars with flower initiation that is transplanted at the end of September and kept warm from mid October to develop flowers
Florida ranks first and second as a producer of fresh market tomato ( Solanum lycopersicum L.) and strawberry ( Fragaria × ananassa ) crops with a total economic value of $426 and $307 million in 2019 (USDA-NASS, 2020), respectively. Weed
Eight strawberry cultivars or advanced selections from the Univ. of California, Davis, breeding program were screened for polymorphisms using the polymerase chain reaction (PCR) and 43 random 10-base DNA primers. Over 60% of the primers screened resulted in replicable polymorphic banding patterns (amplification profiles), and a subset of ten primers that exhibited high levels of amplification profile polymorphism was used to identify each of the eight genotypes uniquely. There was also a significant product-moment correlation (r = 0.64, P < 0.01) between number of shared amplification profile phenotypes and pairwise coefficient of coancestry. This technology shows high promise as a means of verifying the identity of cultivars and developing a genetic map of the octoploid cultivated strawberry.
Feasible protocols for organic hydroponic production of strawberry are necessary and this study compares the yield and fruit quality of organic and conventional inorganic hydroponic production. Some issues identified with organic hydroponic strawberry production are: 1) dominant ammonium nitrogen form; 2) solution alkalinity; and 3) dissolved oxygen level of nutrient solution. Eighty bare-rooted `Diamante' plantlets were planted in coconut fiber pots with a mixture of coconut coir (30%) and perlite (70%) and grown in a modified nutrient film technique system inside a polycarbonate greenhouse. The organic nutrient solution contains mostly ammonium nitrogen and little nitrate nitrogen. To enhance colonization and activities of nitrifying bacteria, coconut fiber mats were placed in the organic nutrient solution reservoir. A similar system was also introduced for stock solution pre-conditioning where nitrification and pH stabilization were achieved before application to the strawberry plantlets. The organic nutrient solution prior to pre-conditioning had only 1.53 mg·L-1 nitrate nitrogen, although the nitrate nitrogen level increased to 63.2 mg·L-1 after pre-conditioning. The organic nutrient solution pH was 4.5 initially, 8.5 after 24 hours of pre-conditioning, and finally, shifted to and stabilized at 5.7–5.9 after 3 days. Dissolved oxygen level is critical for both nitrifying bacteria activities and plantlet root growth; therefore, oxygen enrichment was achieved by constantly aerating the nutrient solution in the reservoir, which raised the oxygen level from 2.5 to 7.4 mg·L-1. Comparisons of yield and quality of strawberry fruits between organic and inorganic nutrient solutions will be presented and further improvements of hydroponic systems will be discussed.
Fall-planted cover crops killed in spring is practiced in strawberry cultivation in different regions of the North America. These systems have shown significant weed suppression and conservation of soil without significant yield reduction in strawberry. During the establishment season, this study was initiated to assess weed suppression with cover crops (`Wheeler' rye and `Micah' and `Steptoe' barley) along with perlite, an artificial plant medium. Strawberry (`Selva' and `Totem') plant growth and weed biomass were measured during 1995-96 season. Small-seeded summer annual weeds were suppressed in cover crop treatments compared to control treatment. `Micah' barley in growth phase suppressed more than 81% of the total weed biomass compared to control plots with no cover crop in early spring. However, in early summer, cover crop residues failed to suppress different types of weeds 60 days after killing of cereal with herbicide (2% glyphosate). Distinct differences in strawberry plant growth were evident between the cover crop treatments and non-cover crop treatments including `Micah' applied on surface. Strawberry growth was doubled during 10 July to 15 Aug. in both cultivars. `Micah' barley applied on surface produced better growth in both strawberry varieties than the growth in other treatments. `Micah' barley applied on soil surface produced 50% more strawberry shoot biomass may indicate the root competition between cover crops and strawberry.
Two experiments were designed to study components of resistance to Colletotrichum acutatum on runners of three strawberry cultivars: incubation period, latent period, length of the lesion and spore production, and infection frequency with three levels of inoculum density (104, 105, 106 spores/cc) were considered. Rate of disease development was also determined. There were significant differences in all the components among the resistant and susceptible cultivars. Both 'Chandler' and 'Sweet Charlie' expressed susceptible reactions. The length of the lesion, number of spores/cm of the lesion, incubation period, latent period, and rate of anthracnose development were statistically similar in 'Chandler' and 'Sweet Charlie'. The only significant difference among them was found in infection frequency. 'Chandler' had a greater number of infection sites with all three concentrations of spores included. The cultivar Pelican showed a high level of partial resistance associated with longer incubation and latent periods, lower number of spores/cm of lesion, shorter lesion, smaller number of infection sites, and lower rate of disease development.
Leaves of three strawberry cultivars (Bounty', `Honeoye', and `Kent') were collected at random from plants growing in an experimental trial at the Agriculture Canada, Research Station farm at Lavaltrie, Quebec. Steam-distillation was carried out on 300g of leaves in 3L of distilled water in a 5L flask. The essential oils were analyscd with a Varian 6000 gas chromatogmph. Thirty-seven compounds were detected of which sixteen were identified. The major components were linalool and nonanal. Many of the other constituents were aliphatic in nature. Differences in oil composition among the three cultivars were observed. Essential oil composition might therefore be used as a selection criteria for insect or disease resistance. Their effect upon mites will be assayed in future studies by testing them as sex, food, or oviposition lures.
Abstract
Seven seedling populations of strawberry were analyzed for ascorbic acid content and color intensity. The amount and type of variation found showed both characters to be controlled by quantitative genes. It is postulated that 2 genetic systems control the inheritance of ascorbic acid and that the 2 systems can interact with each other. Partial dominance was exhibited for high color intensity. Heritability estimates of 41% for ascorbic acid and 81% for color intensity were obtained. Flesh color and ascorbic acid content were not correlated characters.