Topic 15.Gymnosperms and

Angiosperms plants and their value in the rural

economy

• Plan:• General characteristics• Gymnosperms• Angiosperms

••• Literature:• V.G. Khrzhanovsky. "Course of general botany" (I-P tom) 1982. M.

High School.• P.M. Zhukovsky "Botany". M. 1982, High School• Suvorov V.V., Voronova IN- Botany with the basics of geobotany. L.

Kolos. 1979• Andreeva I.I. Rodman L.S. Botanica.-M .: Kolos, 2005,• P.172-175.• Lotova L.I. Botany: .Morphology and anatomy of higher plants.

Uchebnik.-M .: Kom.Kniga, 2007 with..312-321• Barabanov B.I. Zaychikova S.G. Botany: training. for universities.• M.: Publishing center "Academy", 2006-p.82-85• Yakovlev G.P. Chelombitko V.A. Botany: educational for higher

education.• -SPb .: ed.SPhFA, 2003.-129-132 (647 pages.)

• All modern higher plants, the reproduction and distribution of which is carried out with the help of seeds, are often combined together under the common name of seed plants (Spermatiophyta). The presence of seeds this group differs sharply from other modern higher - spore plants: mosses, mushrooms, horsetails, ferns. In the process of evolution, reproduction by seeds was a progressive adaptation of plants. This circumstance enabled seed plants to preserve the embryo for a long time even under adverse conditions

• In seminal plants, macrosporangia do not leave the mother plant until the formation of the formed embryo (macrosporangia falls off as a seed). The germination of macropores, the formation of female sprouts, fertilization and the formation of the embryo proceeds on the mother plant, which supplies the developing individuals with nutrients

• In spore plants, microsporangia on maturation lose their connection with the mother plant. The development of sprouts and spores takes place outside the plant that produced them. This leads to the death of a large number of sprouts because not all of them fall into favorable conditions of existence

• The process of seed formation is associated with the further reduction of the sex generation (gametophyte) and the strong development of the sporophyte. The strongly reduced male seed of the seed is reduced to the formation of a mainly pollen tube, which leads the male gametes formed inside, which lost mobility in most of the seed plants, directly to the egg inside the macroporangia.

• Thus, fertilization here is not connected with the presence of water and this was a great advantage of seed plants in their struggle for the conquest of land. Seed plants occurred in the process of historical development from spore plants. This is proved by their relatively morphological study, which made it possible to establish homology (identity by origin) between the organs of reproduction of seed plants and higher spore plants

• The ancestors of typical seed plants probably were extinct plumaceous and paportnic plants, in which primitive seeds developed.

• Modern seed plants, being a large group, greatly exceed spore by number of species, roles in plant cover, and also in significance for humans.

• Seed plants are divided into more ancient by origin - gymnosperms and later emerged, and more numerous - angiosperms

• Department gymnosperm - Gymnospermae. • This division includes higher plants, characterized by

the presence of seeds and ovules openly lying on carpels, not enclosed in a pestle, as angiosperms. The open position of the ovule is a distinctive feature of the representatives of this department, why they are called gymnosperms. Articulations develop in the ovules of gymnosperms, as in all higher spore plants. For most gymnosperms, real seeds are characteristic of the embryo and endosperm.

• The presence of the seed embryo and its shelter is one of many adaptive properties of the gymnosperms to the terrestrial way of life.

• At the end of the Carboniferous period, a significant climate change took place on the ground towards dryness and cooling. What caused significant changes in the plant world

• Most ferns died out, they were replaced by gymnosperms, which turned out to be more adapted to new, harsh conditions. All gymnosperms are trees or shrubs, among them there are no herbaceous forms.

•• At present, about 600 species of gymnosperms are known.

They are distributed throughout the globe. In Russia representatives of this type - coniferous (pine, spruce, larch, fir, etc.) occupy huge areas in the northern part, as well as in the mountains of the Caucasus and the Urals.

• .

• In the mountains of Uzbekistan, only Archa(juniper) grow from conifers, in Kyrgyzstan -spruce, fir. The gymnosperm division is divided into three classes:

•• 1. The Trumpet-Cycadopsida• 2. Shellfish-Chlamydosptrmatopsida• 3. Thistle- Pinopsida

• The class of Cycadales is divided into three orders:

• 1. Seed ferns; 2. Cycas; 3, Bennetites.• Of the three orders, only a small number of

species of cycads have survived. The other two orders are extinct forms.

•

• Shishkonosnye class - Coniferophyta, this class includes three orders:

• 1. Cordaite (extinct) • 2.Ginkgoed • 3. Coniferous.

• The order of ginkgoids currently contains one family with a single species - Ginkgo biloba(Ginkgo biloba). "Living Fossil" tall tree up to 30-40 m in height and 3-4 m in girth. The cycle of development of ginkgo is very similar to the cycle of development of cycads. According to the structure of the vegetative organs, inflorescences and the anatomical structure of the stem, ginkgo is significantly different from the cadiac and approaches the cordaite.

"Living Fossil" tree Ginkgo bilobate(Ginkgo biloba L.)

• Order coniferous. • Conifers are the most numerous in the number

of genera and species of the order of gymnosperms. These are trees and shrubs with a characteristic anatomical structure of wood, having instead of vessels tracheids with fringed burrows. Almost all conifers have bark in the bark, and in some woods, resin grooves are also developed. The stem of conifers has a weakly developed cortex and a core, the central part of the stem is occupied by the central cylinder

• The stems of conifers have a secondary growth in thickness. Leaves are relatively small, simple, mostly scaly or acicular (needles). Conifers are always green plants, with the exception of larch in which the needles fall down for the winter

• Macrosporophylls and microsporophylls are collected in female and male cones. Real fruits (in the botanical sense) are not found in conifers, since they do not have a pistil from which a fruit is formed. Seeds in some conifers are covered with a woody shell (Siberian pine pine) or surrounded by a fleshy seedling (Tiss); in others, the cones become fleshy (Archa) seeds. About 600 species of conifers are known, many of them are valuable forest-forming species

• Conifers are divided into five families: Araucariaceae,• Taxaceae, Pinaceae, Cupressaceae, Taxoidaceae• Macrosporophylls and microsporophyllsare collected

in female and male cones. Real fruits (in the botanical sense) are not found in conifers, since they do not have a pistil from which a fruit is formed. Seeds in some conifers are covered with a woody shell (Siberian pine pine) or surrounded by a fleshy seedling (Tiss); in others, the cones become fleshy (Archa) seeds. About 600 species of conifers are known, many of them are valuable forest-forming species

Conifers are divided into five families

• Pine•• Pine tree•• Pinus sylvestris•• Siberian Pine•• Pinus sibirica

3. TaxodialSwamp Cypress

Taxodium distihum

• Sequoia Giant• California, USA

• Cypress tree evergreen • Lydney arboretum, • Gloucestershire, • England, 1996•••

The or Chlamydosptrmatopsidacontains one family of ephedra. Representatives of Ephedrales

• About 70 species of Ephedra are known. • In Uzbekistan there are 6 species that grow in

deserts, on pebbles in valleys of rivers, along gravelly slopes of mountains. A number of species germinating in Uzbekistan are used in medicine to produce alkaloid ephedrine.

).•

The order majestic includes one family, one genus and one species - welwitchia amazing (Welwitschia mirabilisThe order majestic includes one family, one genus and one species - welwitchia amazing (Welwitschia mirabilis).

The order majestic includes one family, one genus and one species - welwitchia amazing

(Welwitschia mirabilis

Welvichia remarkable in the conservatory of the

Botanical Garden of New York, 1977.

• This is one of the most remarkable plants in the world in morphology and biology. Stem up to 1 m in diameter and up to 40 cm in height. Only two strap-like, leathery sheets, reaching 3 m in length. Leaves gradually grow at the base, and at the ends are broken into long lobes.

• Welvichiya lives for a long time-100 years or more, as many live her two leaves. The inflorescence appears on the top of the stem. The seed is covered with two fleshy winged covers. Welvichia has a number of features of the structure of the inflorescence and in the processes associated with fertilization, which distinguishes it from gymnosperms. This unique plant is found only in the desert on the south-west coast of Africa.

• Angiospermia (Angiospermae).• Angiosperms stand out among other types of

wealth representatives. Compose about 80% of all higher plants and is characterized by a number of clear signs, sharply distinguishing them from other representatives of the plant world. Their seeds are hidden inside the fruit. Hence their name is angiosperms. These plants are characterized by flowers, consisting of stamens and pistils, differing in a wide variety of forms

• Perianth, with a single exception is missing. Pollination and spreading of seeds and fruits takes place in different ways: with the help of wind, insects, birds, water. In angiosperms, double fertilization occurs, as a result of which not only the embryo but also the endosperm is formed. The ovules turn into seeds, and the ovary into a fruits

• Seeds ripen under the protection of carpels. Morphological and anatomical structure of them is the most difficult in comparison with other types of plants. The internal anatomical structure of angiosperms is characterized by the presence of vessels (exceptions among Magnoliaceae) and an unusual variety of structure as individual vascular bundles and especially secondary wood and bast.

• .

• The protection of the ovule by the membranes and a number of other features makes angiosperms the most highly organized plants. In comparison with their predecessors, who had a less perfect bio-morphological organization, they are better adapted to the modern conditions of life on earth. Venation in angiosperms (especially mesh) is better as it turned out to ensure the continuation of the leaf activity in tearing, eating part of the leaf by insects than all the others

• Angiosperms appeared 120-130 million years ago, much later than other types of plants, but they very quickly replaced the widespread plants - ferns and gymnosperms and took the dominant position.

• Among angiosperms, there are now about 250 thousand species, 10 thousand genera and more than 300 families.

• As you can see, Angiosperms by the number of species occupy a dominant position.

• One of the reasons for this domination is that in the process of evolution of their historical development, angiospermous plants developed such organs as a flower and a fruit in which a seed is enclosed. The fruit protects the seed from the adverse effects of the environment. Thus. angiosperms managed to adapt to the most diverse conditions of existence.

•• A huge variety of angiosperms and their sharp

difference from the corresponding organs of the gymnosperms cause considerable difficulties in explaining the origin of the flower. At the same time, since the flower is the most characteristic organ of angiosperms, the problem of its origin, in fact, is the problem of the origin of flowering plants.

• One of the most famous theories of the pseudantorigin of the flower-the theory of Wettstein-is at present only of historical significance (from the Greek pseudo-complex, antos-flowers). Wettstein believed that among all angiosperms the simplest and most primitive flowers are so-called single-puffed (Monochlamideae), which include beech, birch, elm and other families. Here, the diversity of flowers is characteristic of the strobila of gymnosperms. From Vettshtein's point of view, the most primitive angiosperms have simply arranged flowers with a simple perianth or without a perianth, often dioecious

• Strobilar theory.• The fact that led to the emergence of the

strobiliar theory of Arber and Parkin was the discovery of a remarkable group of Mesozoic gymnosperms - Bennettites with bisexual "flowers" -stroke.

• The general appearance, straight unbranchedtrunks and pinnate leaves, the Bentonitessomewhat resembled palm trees, and even more living gymnosperms-cycads. However, the cradles have dioeciousstrobilae.

• The very different size of the Bennettitestrobilapossessed a well-defined conical axis on which various leaf organs were located.

• Some features of the Bennetian-ripening of them are

• some of the features of the Bennetian-obolocality of their strobilae, the location of the parts, the shape of the axis, have led to the assumption that they are related to the multiparticulate

• According to the strobilar theory, the archaic bisexual strobila, which the gymnosperms did not reach us, lived in the depths of the Mesozoic, was the initial for both the angiosperm flower and the strombler. Similar strobe Arber and Parkinwere called proantostrobilom. It consisted of axis, patchwork, microsporophylls and megasporophylls. Proantrostrobil differs significantly from the flower of angiosperms by the structure of all parts, in particular micro- and megasporophylls.

• According to the strobilar theory, the archaic bisexual strobila, which the gymnosperms that did not reach us, lived in the depths of the Mesozoic, was the initial for both the angiosperm flower and the strombler. Similar strobe Arber and Parkinwere called proantostrobil. It consisted of an axis, patchwork, microsporophylls and megasporophylls. Proantrostrobil differs significantly from the flower of angiosperms by the structure of all parts, in particular micro- and megasporophylls

• It is assumed that in the course of evolution microsporophylls are reduced and the number of microsporangia is reduced to four. Open megasporophylls, closing in edges and growing together, become closed carpels with inside semigus and the pollen begins to be picked up by carpels (in gymnosperms with integrations), anostrobil is formed, ie, formation which is already a flower, but at the same time clearly reveals a strobilic nature

• Thus, we come to the conclusion that the "flower" of angiosperms is limited in growth reproductive amphisporangiocy or, more rarely, monosporangiate escape, which emerged in the process of evolution from the more primitive strobilov of gymnospermicancestors. The "flower" is a shortened axis of the strobila, and "stamens" and "carpels "-real, though highly specialized and often unrecognizable mutated sporophylls.

• Strobilar theory of the flower is confirmed by a huge amount of facts of modern comparative morphology and teratology of plants. The origin of the flower from the amphisporangial strobiles of primitive gymnosperms becomes especially clear when we compare with them such primitive flowers as, for example, a magnolia flower.

• Angiosperms are divided into two classes: dicots and monocots. Each of which is characterized by a complex of special features The most important and most obvious signs of difference between dicotsand monocots.

•• Dicotyledons• Monocotyledons• 1.• Seeds: 2 cotyledons (seed leaves), endosperm present or absent• Seeds: 1 cotyledon (seed leaves), endosperm is often present in

seeds• 2.• The embryonic root grows into the main root bearing the lateral

roots; the root system is more often rod shaped• The embryonic root dies early, instead of the main root,

subordinate roots are formed, the root system is more often friable

• 3.• Life forms: herbaceous and woody• Life forms: more often grassy, very rarely woody

• 4.• Leaves simple and complex, with a mesh and peristonerous

venation, petiolate, broad at the tip, often with stipules• Leaves are simple, with parallel and arcuate venation, acute at

the tip, often sessile with vagina, without stipules• 5.• The stem grows thicker as the plant grows, as the conduction

beams are open, in the transverse section of the stem they are arranged in a circle or there is a single conducting cylinder

• The stem does not thicken, the conductive bundles are closed, on the transverse section of the stem they are arranged as if randomly

• 6.• Flowers are five-membered, less often four-

membered or polynomial.• Flowersthree-membered• 7.• 200-180 thousand species, 10 thousand genera,

325 families• 60 thousandspecies, 3000 genera, 65 families••

• In the 17th century, the English botanist John Ray watched and described one or two cotyledons from germinating plants, but only at the beginning of the 19th century, thanks to the works of Robert Brown, the botanists finally consolidated their consciousness that angiosperms can be divided into two large groups: dicots and monocots.

• Hence it was necessary to find out - which group is primary and which group is secondary?

• Only in the first quarter of the 20th century, the majority of taxonomists were inclined to conclude: monocots derived from dicots.

••••

• At first glance, the difference between monocotyledonous and dicotyledons is large, but some monocots have stipulations, reticular venation and, in some cases, develop major roots.

• At the same time, in bipartite, for example, in Anon, Buttercup and Barberry, the flowers are either of the three-type type or at least the perianth consists of six leaves. A number of dicotyledonous (luticoid, barberry) -vascular bundles are closed.

• All this makes the distinction between monocotyledons and dicotyledons not so sharp and now most botanists accept that monocotyledons represent only a lateral branch of bipartite and deduce them i.e. monocots or from the buttercups.

• In the distribution of monocotyledons and dicots on the globe, one can also notice a difference and a rather large one.

• The number of monocotyledonous species is less than dicotyledonous, But the number of individuals in monocots is very great. Meadows, prairies, steppes for hundreds of kilometers consist of several species of monocotyledonous, often cereal, and occupy areas sometimes of hundreds of square kilometers. The number of their individuals is often estimated in billions.

• Dicotyledons represent a much larger number of species, of which only a few occupy large areas. More often, dicotyledonous plants (species) occupy a small area of distribu on, some mes quite often, they are endemic.

• The development of monocotyledons proceeded in the direction of enabling the development of a large number of individuals of the species, whereas in dicots, the formation of new species is much easier.

• Dicotyledons are more easily and more strongly changed under changing conditions of existence than monocotyledonous plants, (Bonnier'sexperiments in transplanting plants of the plains to the mountains and back.)

• The nutritionally dicots are significantly inferior monocots, very rarely contain starch, proteins (compare cereals), but their seeds are often rich in oil, proteins (true poorly digested), fruits rich in flavorings (apple, pear, pomegranate, lemon, pepper oil et al.), mustard etc.) Most dicotyledons are providers very important for humans different technical products (wood, fibers, colorants, essential oils, etc.).

• Paleobotanist does not provide specific data from which to infer that monocots from dicots really happened as even the oldest remains of angiosperms are represented and those and others.

• In connection with this, it is also not known which groups of dicots are more ancient and are the ancestral forms of angiosperms. Therefore, it is necessary to rely on the morphological study of modern forms and the main thing is to study the arrangement of the flower, since the flower is recognized by all taxonomists as the basis of the system, since this organ of the plant is the most stable, stable and least subject to the influence of habitat conditions on it

• Currently, most morphologists and taxonomists believe that monocotyledonous descended from dicots. This is is:

• 1) Availability of a number of monocotyledons of two cotyledons, and it is possible to prove the gradual reduction of the second cotyledon (cereals); At the same time, a number of representatives with one cotyledon have been found in dicotyledons, which occurs either by reducing one or by splicing two cotyledons (primrose)

• 2) The characteristic is considered to be characteristic of monocots, parallel venation of leaves is also found in dicotyledons; mesh venation of dicotyledonous leaves is also found in monocots.

• 3) Closed vascular bundles, common in monocots, are also found in dicotyledons.

• 4) Three-flowered flowers characteristic of monocotyledons are also found in a number of dicotyledons, and sometimes they are also characteristic of whole families (anon) for the rest of the characteristics of typically dicotyledons.

• .

• 5) The reduction of the main root, although widespread in monocots, is not always observed and there are many dicotyledons, in which it also occurs.

• 6) The development of the embryo in monocots is very different, and the so-called monocotyledon type can be derived from the dicotyledonous

• In all other respects monocotyledons are similar to dicotyledons, and it is not so difficult to imagine the origin of monocotyledons from any dicotyledonous group.

• Such a group is possibly a group of pluriplane, in which all the listed signs of deviation from typical dicotyledons can be found in the family of buttercup and barberry. On the contrary, we do not know of any group of monocotyledons, from which all the signs of dicotyledons could be derived. If we recognize that monocotyledonous descend from dicotyledons, then naturally the forms representing the connection between angiosperms and some of their ancestors should be sought among dicotyledons.

• At the beginning of the angiosperm system, we must set up multiparticulates, to which

• and include magnoliaceae. One of the first such system was created by H. Gallier (1901) and J. Hutchison (1926).

•

• Class Dicotyledonae• An extensive class of flowering plants

containing 325 families and over 180 thousand species. In the number of species, dicotyledons are 4-5 times larger than monocotyledons. They are also more diverse in their life forms. Among dicots, there are considerably more woody plants than among monocots.

• with monocotyledons also significantly more diverse. Rubber, gutta, industrial alkaloids give only dicotyledons.

• Dicotyledons are characterized by the following features:• 1. The embryo has two cotyledons and usually a well

developed main root• 2. Due to the presence of cambium, the stem is capable of

secondary thickening.• 3. Savonic fascicles are open. Leaves are diverse in shape

and dissection and reticular venation.• 4. Flowers in the type of five (five sepals and 5 petals),

have 5 and 10 stamens, and carpels 2 more often (sometimes 3 and 4 and

• 5). The perianth is usually double, However, all of the listed signs are not absolute, but they make it easy to distinguish between dicotyledons and monocots. It should also be noted that no single dicot plant is

• (Chorypetalae) and spinoolepine(Sympetalae).

• The first are characterized by the fact that the parts of the perianth are divided to the ground, as a result of which they come off or fall off separately. The bezpelest plants (Apetalae), whose flowers are completely devoid of the perianth, are also separately bred.

• For spinal lobes, the fusion of the bases of the petals into the tube is characteristic. In the phylogeneticrespect, they stand above the discrete leaves. However, this distinction in the general system of dicotyledons is outdated; in some orders, there may be separate spinal families and spinal-lingual.

• Examples of spleen: Polygonaceae, Chenopodiaceae, Rosaceae, Malvaceae, and others.

• Examples of spinal lobes: onvolvulaceae, Boraginaceae, Solanaceae, Campanulaceae

• Among modern angiosperms, the most primitive are the multiparticulate plants (Magnoliaceae, Lyutik, Barberry, etc.) The basis for such an assertion is the specific structure of a typical multiparticle flower, which is characterized by a large number of primitive characters: convex (conical) peduncle, spindle-shaped corolla with a large number of petals , located spirally, etc.

• QUESTIONS FOR SELF-CONTROL:•

• What are the most important signs that distinguish• gymnosperms from higher spore• How do gymnosperms are classified?• What is the evolutionary significance of the

appearance of a seed in a plant?• What are the most important signs that distinguish

angiosperms from gymnosperms?• What signs distinguish monocotyledons from dicots?

•• THANK YOU FOR ATTENTION!•••