Tag: botany

(A)An apical bud is the one that is at the end of the shoot.

Runner is a modified stem which grows horizontally forward creeping on ground and producing roots at nodes. Common example of plants producing runners are grasses like Cynodon, Oxalis etc.
Grafting is a method of artificial vegetative propagation. It is usually practiced in dicots (like rose, mango etc) and cannot be done in monocots (like sugarcane, bamboo, banana etc) because in monocots vascular cambium is absent.
Adventive embryony is a type of agamospermy in which the gametophytic generation is completely eliminated. The zygotic embryo either degenerates or competes with apomictic embryos. Adventive embryony usually leads to the formation of more than one embryo in a seed. Well known examples of adventive embryony are citrus, cactaceae, euphorbiaceae, orchidaceae etc.

Budding and fission are forms of asexual reproduction, which does not involve gamete fusion or new gene combinations.

Grafting is the process of joining two plants together to grow as one. Grafting increases vegetative reproduction.

In a modification of vegetative reproduction from cuttings, a twig or bud from one plant can be grafted onto a plant of a closely related species or a different variety of the same species. Grafting makes it possible to combine the best qualities of different species or varieties into a single plant. The graft is usually done when the plant is young. The plant that provides the root system is called the stock; the twig grafted onto the stock is referred to as the scion. For example, scions from French varieties of vines that produce superior wine grapes are grafted onto root stocks of American varieties, which are more resistant to certain soil pathogens. The genes of the scion determine the quality of the fruit, so the quality is not diminished by the genetic makeup of the stock. In some cases of grafting, however, the stock can alter the characteristics of the shoot system that develops from the scion. For example, dwarf fruit trees, which allow for easier harvesting of the fruit, are made by grafting normal twigs onto stocks of dwarf varieties that retard the vegetative growth of the shoot system. Because seeds are produced by the part of the plant derived from the scion, they give rise to plants of the scion species when planted.

Scion is a type of vegetative propagation. The process of artificially growing the plants is known as vegetative propagation. Artificial vegetative propagation is usually used for propagation or reproduction of those plants which produce either very few seeds or do not produce viable seeds. Some the examples are Banana, pineapple, artificial rose, orange, grape etc. Layering, grafting, cuttings and tissue culture are some types of artificial propagation. Scion or grafting of a plant means removing the twig or viable bud from the plant and inserting or tying it to the other buds especially the aerial part/stem(Stock) of the other plant. The stock provides the nutritional support to the stock of the plant. 

The rootstock is generally derived from a plant that provided good enough support to stem, roots and branches, resist to the relevant pests and diseases and which obtain necessary water and mineral from the soil.

Layering: In this method, a branch of the plant is pulled towards the ground and a part of it is covered with moist soil leaving the tip of the branch exposed above the ground. After some time, new roots develop from the part of the branch buried in the soil. The branch is then cut off from the parent plant. The part of the branch which has developed roots grows to become a new plant (just like the parent plant). Jasmine plant (chameli) is propagated or produced by the layering method. We can see from that one left side branch and one right side branch of the parent jasmine plant have been buried in moist soil. The parts of branches which are buried in soil grow their own roots. When this happens, the branches of the parent plant connecting the newly formed plants are cut off so that the newly formed plants may grow on their own and develop into mature plants (like the parent plant). Jasmine cannot be propagated by flowers, seeds or stem

Stems are characterized by the presence of nodes and internodes, whereas roots lack these structures.

Plant cutting is the common method for vegetative propagation i.e asexual method by which plant can be grown. This method can be performed by using stem, roots or leaf. Stem cutting when placed in soil produces roots and leaves and grows into a new plant. Sugar cane, roses, citrus, durant, grapes, cocoa, bougainvillea, carnations and many other plants are largely and rapidly propagated by stem cuttings. Thus, the correct answer is option D.