Strawberry is a small, red fruit produced by a low-growing plant. The edible part of the strawberry is an enlarged flower receptacle, while the true fruits are the small achenes on the surface. The modern garden strawberry (Fragaria × ananassa) originated in the 18th century as a natural hybrid between two wild species native to North and South America. Since then, it has been cultivated and selectively bred for fruit size, yield, and other agricultural traits.
Fig.1.strawberry fruit(Hussain et al., 2021)
Botanical Structure and Growth Habit
The strawberry plant is characterized by a short, thickened stem known as the crown, which contains a terminal growing point and produces roots at its base. From this crown, new leaves and flower clusters emerge in early spring via fleshy buds. In regions where commercial cultivation is practiced, the formation of one to two branch crowns during late autumn is desirable. These branch crowns are structurally identical to the main crown and can independently produce inflorescences, thus contributing to higher fruit yield.
Crown development typically occurs at temperatures above 10 °C (50 °F), particularly during October. If average temperatures drop below this threshold in November, the formation of branch crowns and flower development slows significantly. In varieties such as 'Camarosa', the use of row covers in late fall may promote additional reproductive growth. Ideally, a well-developed strawberry plant should have 3 to 5 crowns by the onset of the fruiting season. However, excessive crown formation (more than six per plant) may reduce fruit size, presenting marketing challenges.
Proper planting depth is critical; the crown’s midpoint should be level with the soil surface. Planting too deep risks covering the growing point, while shallow planting may expose the root system, compromising establishment.
Fig. 2.The “growing point” of the strawberry (center). Note the new side stem, or branch crown, that has begun to form in late December.(Poling, 2012)
Leaves and Photosynthetic Function
Strawberry leaves are compound, trifoliate structures borne on petioles arranged in a spiral around the crown. These leaves perform photosynthesis, converting light, water, and carbon dioxide into sugars, which are transported to developing fruits and other tissues. In late fall, sugars are stored as starch in root tissues for winter reserves. Leaf number and total canopy area in fall are strongly correlated with spring fruit production.
Leaf longevity typically ranges from 1 to 3 months. However, factors such as early frosts or suboptimal irrigation can shorten this duration. Sufficient overhead irrigation following transplantation is crucial to retain green foliage and promote healthy root establishment.
Root System and Nutrient Uptake
The strawberry’s root system anchors the plant and facilitates water and nutrient absorption. A healthy root network typically consists of 20–35 primary roots and numerous finer rootlets. Root growth is optimal in soil temperatures between 7–13 °C (45–55 °F). These roots also act as carbohydrate storage organs during winter.
Nutrient uptake includes macronutrients such as nitrogen (N), phosphorus (P), calcium (Ca), potassium (K), sulfur (S), and magnesium (Mg), as well as micronutrients like iron (Fe), manganese (Mn), boron (B), zinc (Zn), and copper (Cu). Micronutrient supplementation, particularly boron via drip irrigation, may be necessary in late winter or early spring.
Floral Morphology and Fruit Development
The strawberry flower comprises five sepals, petals, stamens (male organs), and numerous pistils (female organs) arranged on a conical receptacle. Upon fertilization, the receptacle enlarges and becomes the edible part of the strawberry fruit. The actual fruits are the small achenes—commonly mistaken for seeds—embedded on the surface. Each achene contains a single seed with the potential to grow into a genetically unique seedling, which is why commercial propagation relies on runners for genetic consistency.
Fruit clusters develop hierarchically: primary fruits are the largest and ripen first, followed by secondary, tertiary, and quaternary fruits, which decrease in size and ripen later. Development from blossom to ripe fruit typically spans 20 to 30 days, depending on environmental conditions.
Figure.3. Principal parts of the strawberry flower:(a) receptacle ;(b) pistil and fruit wall;(c) anther; (d) sepal; (e) petal.(Poling, 2012)
Functional Food Properties
Beyond its botanical complexity, the strawberry has garnered attention for its role as a functional food. Rich in bioactive compounds such as anthocyanins, ellagic acid, flavonoids, and vitamin C, strawberries have demonstrated potential in modulating various biomarkers related to chronic diseases. Clinical and preclinical studies suggest that regular strawberry consumption may help improve lipid profiles, reduce oxidative stress, lower inflammatory markers, and support glycemic control. These attributes make strawberries a subject of growing interest in nutritional science and public health research.
Aromatic Profile
The flavor and consumer appeal of strawberries are heavily influenced by their complex aroma volatile composition. Over 360 volatile compounds have been identified in strawberry fruits, including esters, aldehydes, alcohols, terpenoids, and sulfur-containing molecules. Esters are particularly dominant and play a central role in defining the sweet, fruity scent typical of ripe strawberries. This volatile composition is highly influenced by genotype, ripening stage, and environmental factors, making it a dynamic trait of interest for breeders and food scientists alike.
