The diversity of living organisms and their characteristicsstructure and life studies biology. Conditions of seed germination considers its branch, called botany, which includes a section - plant physiology. The main conditions necessary for seed germination are optimum temperature, humidity, free air access, sufficient nutrients for the development of the embryo, as well as the light regime. They will be discussed below.
The seed is formed from the seed germ andangiosperm plants are formed as a result of double fertilization, discovered by S. Navashin in 1861. Its germination occurs at the moment of falling into optimal environmental conditions, called abiotic factors. The germ contained in the seed and consisting of the spine and stalk with germinal leaves, begins to grow, and the seed peel bursts and the seed root first appears. It hardens in the soil and begins to independently absorb water and solutions of mineral salts necessary for the further development of the embryo.
Кроме этих веществ, для прорастания семени и его growth requires organic matter such as starch, proteins and fats. Their germ is either obtained from cotyledons (from dicotyledonous plants, for example, peas, cucumbers, tomatoes, cabbage), or directly from the endosperm located in the seed of monocotyledonous plants (wheat, rice, rye). Thus, favorable abiotic factors and the availability of nutrients are the conditions necessary for seed germination.
Если перед вами поставлено такое задание:Describe the role of the conditions necessary for seed germination; we recommend starting with the coverage of the physiological aspects of these processes, which scientifically explain the main conditions necessary for the development of the embryo. So, germination refers to the transition of a seed from a state of rest further to the vegetative growth of the embryo, ending with the formation of a seedling from it.
Семена некоторых растений могут прорастать сразу same or short time after ripening. In many tree species, for example, in gymnosperms - spruce, pine, cedar, and in the majority of forest herbaceous plants, the seeds have a long dormant period and germinate only after 1-2 years or more. This time interval is very important. Thus, in plants of temperate latitudes, germination is stimulated by low winter temperatures. Such a factor of the external environment, such as light, does not always affect the conditions of seed germination, as most of them develop in the dark.
The most important conditions for seed germination arefavorable abiotic factors, among which the temperature performs one of the main functions. In agronomy, plants are classified as cold-resistant and heat-loving. This differentiation also applies to seeds. Some, for example, carrot, lettuce, onion seeds, germinate at low positive temperatures, others (pumpkin, tomatoes, cucumbers) require the soil to warm up to a temperature of +10 - +12 degrees.
In the vegetable industry often use this methodincrease seed germination, as their heating. To do this, you can use electrical appliances, and the seeds of the pumpkin family: cucumbers, zucchini, watermelons, legumes (beans, peas, soybeans) are soaked in water with a temperature of 35-45 ° C, and then cooled, dried. Warming up the seeds for one to two weeks before sowing into the soil increases the energy of their germination, preventing the delay of the growing season, increases the yield.
Continuing to study the conditions necessary forseed germination, we will focus on the value of water. Its presence in the soil provides the processes of swelling of the seed coat, activation of starch hydrolysis. The germination process itself starts from the moment the seeds absorb a large amount of water, which goes directly to the embryo. Its cells actively absorb the glucose solution and begin to divide rapidly, which contributes to the growth of the germinal root. For example, beet seeds absorb water 1.2 times their mass, and clover 1.5 times. In private farms, a method of soaking seeds in water is widely used, ensuring germination of the germinal root.
Рассматривая главные условия прорастания семян, We note the need for free access of air, which is used to provide intensive respiration processes for moistened seeds. In agriculture, bubbling is often used: mixing seeds in water under the action of oxygen or air supplied from a compressor. The most often sparse seeds with low germination energy (carrots, parsnips, onions).
If you turn to a modern landowner with the requestdetermine the conditions of seed germination, then in response, in addition to all known abiotic factors, we will hear a proposal to use microbiological preparations, for example, such as “Baikal EM-1”, containing lactic acid, photosynthetic microorganisms and fungi, for example, yeast. In a solution of this drug soaked prepared for planting seeds for 2-3 hours. This technology stimulates growth processes and enhances the seed germination energy, and also increases the plant immunity to agricultural pests and increases the yield.
To consider all the conditions of seed germination,it is necessary to dwell on a method such as scarification (artificial damage to the seed coat manually). To do this, use a mixture of seeds with coarse sand or metal filings. Due to chafing, the seed coat is damaged. Thanks to this technique, the water necessary for seed germination gets to the germ faster.
Availability of sufficient nutrientssubstances - an important condition for the germination of seeds, especially those that are small in size, and therefore, a small stock of its own nutrients. Seeds of tomatoes, onions, carrots, cabbage are deflated, that is, covered with a layer of nutritious organic substances that adhere to the seed with the help of a solution of starch - paste or freshly prepared mullein. Before drageeing, seeds are calibrated, that is, sorted, leaving the largest and most regular shapes. This method, which affects the conditions of seed germination, enhances their germination and enhances the germination energy.
This article highlighted the main conditionsseed germination, namely moisture, the optimum temperature depending on the plant species and its variety, the presence of oxygen in the air and in the soil, an adequate supply of nutrients for the development of the embryo and modern methods that improve seed germination conditions.
