Plant classification based on light

(I) Factors Affecting Lighting Stage
In the light stage, light is the main factor in the differentiation and development of flower buds, which is reflected in the effect of photoperiod on growth and development. The photoperiod is not only difficult to control flower bud differentiation and its development, but also affects other growth and development of plants, such as branching habits, formation of underground organs such as tubers, bulbs, tube roots, and aging, shedding and dormancy of other organs. In addition, the temperature in the light stage is also a great role, such as the use of integrator test, obtained Lilium longiflorum and high temperatures above 15 °C to promote flower bud differentiation, freesia, narcissus, tulip verdure after the completion of Under long day conditions, flower bud differentiation temperature is 10°C-15°C.
(2) Types of flowers responding to sunshine 1 Long-day flowers The daily sunshine of 12-15 hours is required to promote flowering. If it is under the constant light of day and night, it can play a better promoting role. On the contrary, under shorter sunshine, flowering does not occur or flowering is delayed. Under natural conditions, spring and summer flowering two-year-old and multi-year-old flowers are all of the sunshine flowers. After the sowing of flowers in the second year, Qiu Qiu underwent vegetative growth under cool and cold weather conditions, and flowered rapidly under the spring repertoire. When cineraria and violets are cultivated in the greenhouse, they are normally sown in July-August and bloom in the early spring from January to February; if they are planted in late September-October, they can also bloom under the long spring repertoire. Full growth and become short. The perennial flowers that bloom in early spring, such as heart bamboo and coneflower Phlox, bloom in the spring. When long-day flowers are cultivated in the northern winter greenhouse, in addition to the high temperature, electric lighting is also used to extend the lighting time before flowering. Long-day plants account for half of all plants, and are mainly divided into high-latitude regions.
2 Short-day flowers can promote flowering under short-day conditions with daily sunshine of 8-12 hours, but they cannot flower or delay flowering under long-term lighting conditions. The annual flower is planted in spring under natural conditions, so it grows in the sunshine, grows its stem and leaves, and blooms in the autumn under short sunshine. If sowing late in spring, when entering the fall, although the aphids are short, but in the short-day conditions, the flowers still bloom on schedule. For example, cosmos is usually sown in April and begins flowering in mid-August, and the plant height can reach 2m. If it is planted in June-July, it will still bloom in mid-September, but the plant height is only 1.0m. The autumn flowering perennial flowers are many short-day plants, such as chrysanthemums, poinsettia, strings of reds, asters, cosmoses and so on. Although springs and autumns have the same short days, the temperature during the short days in the spring is still low, and the short-day plants usually have not reached the flowering stage, so they have nothing to do with flowering. The high temperature in autumn is suitable for plant growth and development, so sunshine can affect plant flowering. Short-day plants account for about 26% of all plants, mainly in low latitudes. In the mid-latitudes (temperate zone), both the long-day and short-day conditions are right, so both long-day and short-day plants can survive.
3. Neutral flowers can bloom under relatively long or short light, and have a wide range of adaptation to the length of light, and can flower under 8-16h light. Such as rose, dahlia, carnation, hibiscus, African violet, flower tobacco, gerbera, off some sunflower, carnation flower, carnation, petunia and so on. General neutral flowers can be cultivated for an anniversary. About 24% of all plants, mainly produced in tropical regions.
Some professors such as Wien and Maeger of the Netherlands, and Japan Pumps believe that the above-mentioned assumption limit of the type of flower sunshine response is inaccurate, and pointed out that it should be classified according to the length of critical sunshine, and the critical length of sunshine is to induce flowering. Sunshine length. According to the difference in the length of critical sunshine, plants are divided into six types: short-day plants, long-day plants, neutral plants, sunday or intermediate plants, long and short-day plants, and short-day long-day plants.