Red Light Affects Flowering Under Long Days in a Short-day Strawberry Cultivar

Abstract

<jats:p>July-plugged transplants of short-day cv. Strawberry Festival (<jats:italic>Fragaria</jats:italic> ×<jats:italic>ananassa</jats:italic>) flowered in October and November although they were grown under long photoperiods and warm temperatures (greater than 21 °C) in July and August. These unexpected results were attributed to a high plant density (320 transplants/m<jats:sup>2</jats:sup>) that provided continuous and heavy leaf cover, which eliminated red light (less than 700 nm) from reaching the crowns. This hypothesis was tested by illuminating crowns of transplants growing in 50-cell packs for 16 h·d<jats:sup>−1</jats:sup> with red light-emitting diode lamps (maximum wavelength at 639 nm and 80% of output between 617 and 655 nm). Red light treatment caused a significant reduction in fall flowering. It is proposed that a high ratio of far-red light to visible light reaching the crown will play a role in floral bud induction, possibly as early as mid-August. Transplants of some short-day cultivars started as plug plants in early July have the capacity to flower and fruit in the fall and the next spring, enabling growers in the mid-Atlantic coast region to obtain two harvests within 1 year from a single planting.</jats:p>

Light-emitting Diodes for Manipulating the Phytochrome Apparatus

“…Spectral distribution of low-output red light-emitting diodes used to alter the phytochrome photostationary state (F) of high-density strawberry plants before transplanting in high tunnels (inset). (Data derived from Takeda et al, 2008. )…”

“…This unexpected result was attributed to very high planting density (200 plant/m 2 ) of the plug plants in the greenhouse. Takeda et al (2008) stated that broad spectra light was absorbed by the canopy, but only wavelengths greater than 700 nm were being detected by the crown, resulting in an F < 0.2 at crown level. It was hypothesized that the early flowering response was phytochrome-mediated.…”

RNA-seq Analysis of Meristem Cells Identifies the <i>FaFT3</i> Gene as a Common Floral Inducer in Japanese Cultivated Strawberry

“…PhyA exists in two photo-interconvertible forms termed Pr and Pfr, which absorb red light and far-red light, respectively (Sheerin and Hiltbrunner, 2017;Wang and Wang, 2015). Interestingly, illumination of the crowns of the cultivated strawberry 'Strawberry Festival' with red light resulted in a significant decrease in the number of flowering plants (Takeda et al, 2008). Taking into account the fact that the strawberry cultivar 'Carmine' maintained at a high plant density during the vegetative phase flowered under flower-noninductive high temperature and long-day conditions (Takeda and Newell, 2006), Takeda et al (2008) proposed that a high Pr:Pfr ratio would favor the activation of the flowering pathway in cultivated strawberry.…”

“…Interestingly, illumination of the crowns of the cultivated strawberry 'Strawberry Festival' with red light resulted in a significant decrease in the number of flowering plants (Takeda et al, 2008). Taking into account the fact that the strawberry cultivar 'Carmine' maintained at a high plant density during the vegetative phase flowered under flower-noninductive high temperature and long-day conditions (Takeda and Newell, 2006), Takeda et al (2008) proposed that a high Pr:Pfr ratio would favor the activation of the flowering pathway in cultivated strawberry. Our finding that phyArelated genes are highly expressed in the vegetative meristem of 'Tochiotome' suggests that cultivated strawberries perceive the photoperiodic stimuli not only in leaves, but also in the crown harboring the vegetative meristem.…”

Extended Supplementation of Nutrient Solution for Runner Plant Production Improved the Growth of Runner Plants and Enhanced the Reproduction Rate and Quality of ‘Maehyang’ Strawberry Fruits

“…Furthermore, fast shipments can boost price competitiveness. For that reason, in order to induce flower bud differentiation during the nursery period of strawberry cultivation from August to September, previous studies have focused on low-temperature storage of runner plants (Yoshida et al, 2012), low-temperature and SD conditions (Ruan et al, 2011;Sønsteby et al, 2016), red LEDs (600 to 700 nm) affecting strawberry flowering (Takeda et al, 2008), end-of-day far-red (735 nm) and plant age affecting strawberry flowering (Zahedi and Sarikhani, 2016), SD conditions and timing of nitrogen fertilization period (Sønsteby et al, 2009), timing of nutrient starvation , and defoliation of strawberry. However, it is difficult to apply these techniques in conventional farms due to costs associated with facility maintenance, electricity and achieving the low-temperature and SD conditions.…”