Introduction

storage sunflower granary

Preservation and rational use of all grown crops is one of the main tasks of the state. Due to the seasonality of agricultural production, there is a need to store agricultural products for their use for various needs for a year or more.

Products from the processing of oilseeds are the most valuable food product for everyday consumption, as well as raw materials for many sectors of the national economy.

Sunflower seed grain is stored by producers at oil and fat enterprises, seed processing plants and breeding stations. In this connection, ignorance of the basic science of storage can cause unacceptable losses and deterioration in the quality of grain during storage.

In this regard, the justification and development of new technologies for post-harvest processing of sunflower seeds, which allows not only to preserve, but also to improve the quality of seeds by accelerating their post-harvest ripening, is relevant.

Thus, the purpose of the course work is to determine ways to preserve sunflower seeds and improve their sowing qualities.

The main tasks are as follows: to study the methods and modes of storing sunflower grain, to calculate the nominal capacity of the granary and to calculate the material balance.

Sunflower grain mass as a storage object

Sunflower is an annual herbaceous plant up to 2.5 m high. The stem is dense and erect. The leaves are alternate, large, rough, located on long petioles. Blooms in July - August. The flowers are yellow, apical, collected in a large basket, which turns towards the sun. The flowers in the central part of the basket are small, and the bright yellow ligulate ones are much longer. The fruit is an oblong ovoid achene, striped or black. Ripens in August - September.

The homeland of sunflower is North America. There is archaeological evidence of sunflower cultivation in what is now New Mexico around 3000 BC. e. Some archaeologists claim that sunflowers were domesticated even before wheat. It was brought to Russia by Peter I. Now it is cultivated almost all over the world.

Structure and chemical composition of sunflower grain

Beneath the fruit shell is a thin layer of endosperm that covers the embryo. The embryo consists of two cotyledons. Between the cotyledons, at one end there are a stem and a root. In sunflower seeds (Fig. 1), the embryo is highly developed and occupies the main volume of the seed; The endosperm consists of one row of cells.

Figure 1 - Sunflower achene:

A - cross section of the achene; B - longitudinal section of the achene; B - tangential section of the achene (the air cavity surrounds the entire seed); 1 - air duct cavities; 2 - procambium; 3 - gemmule; 4 - fruit shell; 5 - seed coat.

Chemicals are distributed unevenly across individual anatomical parts of the grain.

The embryo contains a lot of proteins, sugars, lipids, vitamins, and there are more pentosans and ash substances than in the endosperm. The shells consist mainly of fiber and hemicelluloses - substances that are not digestible by humans. The aleurone layer is rich in proteins and fat.

Sunflower seeds contain enzymes that act as regulators of biochemical processes occurring during their formation and post-harvest processing. Of the large number of enzymes, the most important are proteases that break down protein substances, amylases that break down starch, and lipases that break down lipids. The function of regulators of biochemical processes is performed by another group of substances - vitamins. Sunflower seeds contain many important vitamins: retinol, tocopherol, biotin, B vitamins - thiamine, riboflavin, pyridoxine. In addition to the listed chemicals, pigments that color fruits, seeds and grain products play an important role. These include: carotenoids, chlorophyll, anthocyanins, flavones.

The chemical composition of grain is constantly changing. Changes manifest themselves from the moment the seeds are sown in the field, during the period of plant growth and development, during ripening, harvesting, storage and processing of grain at enterprises.

In oilseeds, the protein content is 12 - 30%, nitrogenous substances - 13 - 19%. In terms of content in grain, carbohydrates, which represent the main energy resources, are in first place.

The composition of fruits and seeds, along with proteins and carbohydrates, includes lipids. Their highest content is in the group of oilseeds: up to 55%.

Seeds of flowering plants vary in shape and size: they can reach several tens of centimeters (palm trees) and be almost indistinguishable (orchids, broomrape).

Shape: spherical, elongated spherical, cylindrical. Thanks to this shape, minimal contact of the seed surface with the environment is ensured. This allows the seeds to more easily tolerate unfavorable conditions.

Seed structure

The outside of the seed is covered with a seed coat. The surface of the seeds is usually smooth, but it can also be rough, with spines, ribs, hairs, papillae and other outgrowths of the seed coat. All these formations are adaptation to seed dispersal.

A scar and pollen passage are visible on the surface of the seeds. Rib- trace from the peduncle, with the help of which the seed was attached to the wall of the ovary, pollen passage stored as a small hole in the seed coat.

The main part of the seed is located under the skin. embryo Many plants have specialized storage tissue in their seeds - endosperm. In those seeds that do not have endosperm, nutrients are deposited in the cotyledons of the embryo.

The structure of seeds of monocotyledonous and dicotyledonous plants is not the same. A typical dicotyledonous plant is beans, and a typical monocotyledonous plant is rye.

The main difference in the structure of seeds of monocots and dicotyledons is the presence of two cotyledons in the embryo in dicotyledons and one in monocotyledonous plants.

Their functions are different: in dicotyledonous seeds the cotyledons contain nutrients, they are thick and fleshy (beans).

In monocots, the only cotyledon is the scutellum - a thin plate located between the embryo and the endosperm of the seed and tightly adjacent to the endosperm (rye). When the seed germinates, the scutellum cells absorb nutrients from the endosperm and supply them to the embryo. The second cotyledon is reduced or absent.

Conditions for seed germination

Seeds of flowering plants can withstand unfavorable conditions for a long time, preserving the embryo. Seeds with a living embryo can germinate and give rise to a new plant; they are called germinated. Seeds with a dead embryo become not germinating they cannot germinate.

For seed germination, a set of favorable conditions is necessary: ​​the presence of a certain temperature, water, air access.

Temperature. The range of temperature variations at which seeds can germinate depends on their geographic origin. “Northerners” need a lower temperature than people from southern countries. Thus, wheat seeds germinate at temperatures from 0° to +1°C, and corn seeds - at + 12°C. This must be taken into account when setting sowing dates.

The second condition for seed germination is availability of water. Only well-moistened seeds can germinate. The need for water for seed swelling depends on the composition of nutrients. Seeds rich in proteins (peas, beans) absorb the greatest amount of water, and seeds rich in fat (sunflower) absorb the least amount of water.

Water, penetrating through the spermatic opening (pollen opening) and through the seed coat, removes the seed from the dormant state. First of all, breathing sharply increases and enzymes are activated. Under the influence of enzymes, reserve nutrients are converted into a mobile, easily digestible form. Fats and starch are converted into organic acids and sugars, and proteins into amino acids.

Breathing Seeds

Active respiration of swelling seeds requires access to oxygen. During breathing, heat is generated. Raw seeds have more active respiration than dry seeds. If raw seeds are folded in a thick layer, they quickly heat up and their embryos die. Therefore, only dry seeds are poured into storage and stored in well-ventilated areas. For sowing, larger and more complete seeds should be selected without admixture of weed seeds.

Seeds are cleaned and sorted using sorting and grain cleaning machines. Before sowing, the quality of the seeds is checked: germination, viability, moisture, infestation with pests and diseases.

When sowing, it is necessary to take into account the depth of seed placement in the soil. Small seeds should be sown at a depth of 1-2cm (onions, carrots, dill), large ones - at a depth of 4-5cm (beans, pumpkin). The depth of seed placement also depends on the type of soil. In sandy soils they sow somewhat deeper, and in clay soils - shallower. In the presence of a set of favorable conditions, germinating seeds begin to germinate and give rise to new plants. Young plants that develop from a seed embryo are called seedlings.

In the seeds of any plant, germination begins with the elongation of the embryonic root and its exit through the pollen passage. At the moment of germination, the embryo feeds heterotrophically, using the nutrient reserves contained in the seed.

In some plants, during germination, the cotyledons are carried above the soil surface and become the first assimilation leaves. This aboveground type of germination (pumpkin, maple). In others, the cotyledons remain underground and are a source of nutrition for the seedling (pea). Autotrophic nutrition begins after the appearance of shoots with green leaves above the ground. This underground type of germination.

1. Fill out the diagram

Vegetative - root, shoot

Generative - flower, fruit

2. Complete the laboratory work “Structure of seeds of dicotyledonous plants” (see p. 9 of the textbook). Label the parts of a bean seed in the picture.

1 - stalk

2 - kidney

3 - spine

4 - cotyledons

5 - seed coat

3. Complete the laboratory work “Structure of the grain of wheat” (see p. 10 of the textbook). Label the parts of a wheat grain in the picture.

1 - pericarp

2 - endosperm

4 - kidney

5 - stalk

6 - spine

7 - embryo

Conclusion: beans are a dicotyledonous plant, therefore they have 2 cotyledons. Wheat is a monocot and has one cotyledon and endosperm.

4. Fill out the table "Comparison of seeds of dicotyledonous and monocotyledonous plants"

Plants	Seed parts	Parts of the embryo	Nutrient supply
	Embryo, seed coat	Cotyledons, root, stalk, bud	cotyledons
wheat		scutellum, root, stalk, bud	endosperm
almond	Embryo, seed coat, endosperm residue		cotyledons
onion	Embryo, seed coat, endosperm	root, stalk, bud, cotyledon	endosperm
ash	Embryo, seed coat, endosperm	root, stalk, growth cone, cotyledons	endosperm
ditty	Embryo, seed coat	root, stalk, bud, cotyledon	cotyledons

5. Compare the parts of the seed and sprout. Show with arrows on the diagram from which parts of the seed the corresponding parts of the seedling developed

Conclusion: From the bud - the leaves, from the stem - the stem, from the root - the root, from the cotyledons - the first 2 leaves. Conclusion: from each part of the embryo and seed a certain part of the plant develops.

6. Study the structure of an apple, pumpkin or sunflower seed. Sketch the structure of one of the seeds. Analyze the structure of the seed you studied and draw a conclusion.

A pumpkin seed consists of an embryo, 2 cotyledons, and a seed coat. There is no endosperm. The function of storing substances is performed by the cotyledons. The type of pumpkin seeds is dicotyledonous seeds without endosperm.

7. Explain why seed plants are the most common in nature.

Seed plants have the most developed adaptations for reproduction - double fertilization, which does not require water, protection of the embryo by the seed coat, the presence of nutrients for the embryo contained in the cotyledons or endosperm

Seed - an organ of sexual reproduction and dispersal of plants, developing mainly from a fertilized ovule. The development of the embryo and seeds after double fertilization is called "amphimixis"(from Greek amphi- at both sides). Development of the embryo and seeds can occur without fertilization - apomixis. As a result of apomixis during megasporogenesis, meiosis does not occur, therefore all cells of the embryo sac are diploid. The embryo can be formed from an egg (parthenogenesis), from any other cell of the embryo sac (apogamy), from nucellus cells, etc. Apomixis often occurs in representatives of the rose, rue, nightshade, aster, and bluegrass families. Seed consists of the embryo, endosperm, and seed coat. The embryo is a miniature sporophyte that is the main part of the seed. It contains 3 embryonic organs: the embryonic root, the embryonic stalk with the embryonic bud, and the embryonic leaves (cotyledons). The embryonic shoot is represented by an axis (embryo stalk) and cotyledon leaves, or cotyledons: 2 - in dicotyledons and 1 - in monocotyledons (in the embryo of monocotyledons, the primordia of 2 cotyledons are outlined, but one of them does not receive further development). The portion of the stalk in the embryo above the cotyledons is called epicotyl, or epicotyledonous knee, below the cotyledons - hypocotyl, or subcotyledonous knee. The seed coat is usually multi-layered and is always present in the seed. Its main function is to protect the embryo from excessive drying; it also protects the embryo from premature germination. During germination, the first portions of water penetrate into the seed through a hole in the seed coat - the micropyle. The endosperm usually consists of round cells of storage tissue. These can be grains of starch or drops of fatty oil, often in combination with storage proteins. Endosperm substances are hydrolyzed when seeds swell under the action of enzymes and are absorbed by the embryo during germination; After this, its cells are destroyed. Types of seeds There are 4 types of seeds: 1) with endosperm; 2) with endosperm and perisperm; 3) with perisperm; 4) without endosperm and perisperm. Dicotyledonous seeds without endosperm. This category includes seeds of legumes, pumpkin, asteraceae, cruciferous plants, oak, birch, maple, etc. Figure 4.15 shows the structure of the seed and embryo of a pumpkin (Cucurbita rero). Under the dense skin there is a flat embryo with large cotyledons, in the tissues of which nutrient reserves are concentrated. There is no endosperm - it is “eaten” during the process of seed maturation. On the cotyledons, rudimentary venation is noticeable. The embryo axis is small, with the root pole facing the micropyle; At the same end of the seed there is a hilum. The embryonic bud is poorly expressed: on the cone of growth of the shoot, leaf tubercles are barely noticeable - the primordia of the leaves following the cotyledons. A common educational object is legume seeds. Figure 4.16 shows details of the structure of a mature bean seed, where there is no endosperm and the storage organs are large, very thickened Rice. 4.16. Dicotyledonous seeds: castor bean (with endosperm); beans, pumpkins (without endosperm): A - castor bean: a — appearance of the seed; b - longitudinal section in the plane of the cotyledons of the embryo; c - longitudinal section perpendicular to the plane of the cotyledons; d - isolated and half-expanded embryo; B - beans: a - isolated embryo; b - dissected embryo; c - diagram of the embryo in a straightened form); B - pumpkin: a, b - longitudinal section of the seed in mutually perpendicular planes; c - dissected embryo; 1 - epithelium; 2 - seed coat; 3 - embryo; 4 - endosperm; 5 - cotyledons; 6 - hypocotyl; 7 - epicotyl; 8 - germinal root; 9 - bud cotyledon leaves of the embryo. The embryonic bud with the epicotyl, the 1st internode of the shoot, is well developed. The embryo of the bean (and other legumes) is strongly bent due to the uneven growth of the axis. If you mentally straighten its axis and cotyledons, you will get a diagram that is no different from the diagram of a straight embryo of a pumpkin, etc. A bent or spirally twisted embryo, sometimes with cotyledons folded in various ways, is found in many dicotyledons, including cruciferous plants (cabbage, radishes, etc. .). Dicotyledonous seeds with endosperm. Between the cotyledons there is a shoot growth cone; the bud is not yet formed (in castor bean seeds) (see Fig. 4.16). Dicotyledonous seeds with perisperm and endosperm. Sometimes, in addition to the endosperm, the seeds develop storage tissue of a different origin - perisperm, which arises from the nucellus of the ovule and lies under the skin. Functionally, endosperm and perisperm are equivalent, although morphologically they have different origins: they are analogs, but not homologs (in beet seed) (Fig. 4.17). For example, in black pepper seed (Piper nigrum) a small dicotyledonous embryo is immersed in a small endosperm, and a powerful perisperm is located outside of it (see Fig. 4.17). Sometimes the endosperm in a mature seed is completely absorbed, but the perisperm remains and grows, as in carnation, quinoa (for example, chickweed, cockle, beet). Rice. 4.17. Seeds of dicotyledonous plants with perisperm: A - fruit of black pepper; B - immature beet seed (endosperm is visible, which then disappears); 1 - embryo; 2 - endosperm; 3 - seed coat; 4 - perisperm; 5 - pericarp Monocot seeds with endosperm. The vast majority of monocot seeds belong to this category. One of the most obvious examples of the typical structure of a monocot seed is the seed of an iris or iris (any species, wild or cultivated). Figure 4.18 shows the structure of a yellow water iris seed (Iris pseudacorus). Large, flattened seeds ripen in a fruit-box and are covered with a dense brown skin. The inner layer of the peel usually lags behind the outer layer, forming an air chamber. This helps to increase the buoyancy of the seeds distributed with the flow of water. Most of the seed volume is occupied by endosperm, rich in oils and proteins. A rod-shaped straight embryo is immersed in it. The root primordium faces the micropyle with its tip; it passes into a straight hypocotyl, ending in a meristematic apex (apex) of the shoot, displaced laterally. Cotyledon cylindrical; its lower part is the vagina, covering the growth cone on all sides and covering it. The function of the cotyledon vagina is to protect the growth point. The embryos of many representatives of the Liliaceae, the central family of monocots, are very similar to the iris embryo, for example, onions (Allium sulfur).Rice. 4.18. Seeds of monocotyledonous plants with endosperm (A - iris) and without endosperm (B, C - plantain): A - iris; B, C - plantain chastuha (B - immature seed, the remainder of the endosperm is visible, B - mature, without endosperm); In the immature chastukha seed (B) the remainder of the endosperm is visible, in the mature seed (C) the endosperm disappears; 1 - air cavity; 2 - seed coat; 3 - endosperm; 4 - embryo; 5 - kidney; 6 - cotyledons; 7 - pericarp Cereal seeds. The structure of the cereal seed (family Roaseae) quite peculiar (Fig. 4.19). The embryo in the grain fruit is in contact with the endosperm on one side, and is not surrounded by its tissue, as in most other monocots. Due to this arrangement, the cotyledons of cereals have a flat shape shield, pressed against the endosperm. The suction function of the shield is provided by highly specialized cells of its surface layer. Unlike most monocots, the embryonic bud of cereals is usually quite highly developed and has several leaf primordia. The outer cap-shaped leaf of the kidney is called coleoptile. The hypocotyl in cereals is underdeveloped; the embryonic root is surrounded by a special multilayer sheath - coleorrhiza, which swells during germination, suction hairs develop on its surface, the root breaks through the coleorhiza tissue to emerge out into the soil. The functional significance of the parts of the embryo of cereals is generally clear: protection of the meristematic growth cones by the coleoptile and coleorhiza; at the same time, there are very contradictory hypotheses about the origin and morphological nature of most of the embryonic organs of cereals. The embryo of cereals has a structure much more complex and specialized than that of most others monocots, and therefore cannot be considered the standard for this entire class. Monocot seeds without endosperm. The seed has the shape of a horseshoe; under the thin skin there is an embryo, which concentrates in the cotyledon all the reserves absorbed by it during the ripening of the seed; the endosperm has already been “eaten” by it. An example is the seeds of the widespread semi-aquatic plant arrowhead (Sagiltaria) and plantain chastuhi (Alisma plantago-aquatica)(see Fig. 4.18), as well as completely submerged species of the genus Rdest (Potamogeton).Seed germination Flowering plants reproduce by seeds that ripen inside the fruit. However, in many cases (for example, if the fruits are dry, single-seeded), the seeds spread without being separated from the pericarp. In such cases, the seed material is not seeds, but fruits or parts thereof. If the fruits grow together, the seed material is morphologically a fruit seed. For the germination of seeds (many fruit and wild woody ones) a period of low temperatures is required. For faster germination under cultural conditions, the seeds of such plants are subjected to stratification - long-term exposure at low temperatures, in a humid environment and with good aeration. Sometimes the seed coats are waterproof (hard seed legumes or stone fruits). Such seeds are subjected to scarification (artificial disruption of the integrity of the seed cover by grinding, cutting, passing through metal brushes). The germination of the seed is preceded by its swelling - a process associated with the absorption of a large amount of water and watering of the seed tissue. Simultaneously with the absorption of water, enzymes are activated, which convert the reserve substances of the seed into an easily digestible form accessible to the embryo. For seed germination, water(mature seed tissues are severely dehydrated), oxygen for breathing, defined temperature, and sometimes light. Seed germination is their transition from a dormant state to the growth of the embryo and the formation of a seedling. At the first stages of development, the seedling feeds on organic substances stored in the seed, i.e. heterotrophic. With the appearance of the first middle leaf, the seedling turns into a seedling, which begins to independently synthesize organic substances. However, for some time he continues to use the reserves Rice. 4.19. Wheat grain: With diagram of a longitudinal section of a wheat grain; 1 - caryopsis covers; 2 - endosperm; 3 — shield; 4 - kidney; 5 - epiblast; 6 - main root Rice. 4.20. Scheme of aboveground and underground germination of dicotyledonous plants: A - beginning of seed germination; B, C - stages of above-ground germination; D, E - stages of underground germination; 1 - cotyledons; 2 — hypocotyl (highlighted in black); 3 - main root; 4 - epicotyl; 5 — adventitious roots; 6 - lateral roots; 7 - scale-like leaves of the seed, i.e. His nutrition at this stage is mixed. And only later does the seedling completely switch to autotrophic nutrition. Germination can be aboveground or underground. During aboveground germination(Fig. 4.20) the cotyledons are brought to the surface, turn green and become the first assimilating leaves. The removal of cotyledons above the soil in dicotyledons most often occurs due to the elongation of the hypocotyl (beans, pumpkin, maple) or as a result of the growth of cotyledon petioles (monkshood). The hypocotyl, coming to the surface, straightens and pulls out the cotyledons. During aboveground germination of monocots (onion, crow's eye), the emergence of the cotyledon to the surface is different: due to the intercalary growth of the base of the cotyledon itself, which bends in a loop, and in the absence of growth of the hypocotyl. During underground germination cotyledons, as a rule, shrink and die without coming to the surface, remain in the soil and serve as a receptacle for reserve nutrients or as a haustorium, transferring them from storage tissues to the seedling (peas, oak, nasturtium, wheat, corn), and the first assimilating leaves are the following true leaves behind the cotyledons (see Fig. 4.20). During underground germination, the growth of the hypocotyl is limited, and the shoot immediately begins to grow upward.

1) Fill out the diagram.

2) Complete the laboratory work “Structure of seeds of dicotyledonous plants” (see p. 9 of the textbook). Label the parts of a bean seed in the picture.

3) Complete the laboratory work “Structure of wheat grain” (see p. 10 of the textbook). Label the parts of a wheat grain in the picture.

4) Fill out the table "Comparison of seeds of dicotyledonous and monocotyledonous plants."

6) Study the structure of an apple, pumpkin or sunflower seed. Sketch the structure of one of the seeds. Analyze the structure of the seed you studied and draw a conclusion.

Conclusion: A pumpkin seed consists of an embryo, 2 cotyledons, and a seed coat. There is no endosperm. The function of storing substances is performed by the cotyledons. The type of pumpkin seeds is dicotyledonous seeds without endosperm.

7) Explain why seed plants are the most common in nature.

Answer: Seed plants have the most developed adaptations for reproduction - double fertilization, which does not require water, protection of the embryo by the seed coat, and the presence of nutrients for the embryo contained in the cotyledons or endosperm.