تطعيم النباتات: الأسس والفوائد

Study Notes

Grafting is the connection of plant tissues using new tissues, causing them to grow as one plant.
The root-forming part is called the stock.
The added part, containing buds, is called the scion.
Grafting is successful in dicots because they have cambium tissue that divides and produces parenchymal cells and callus.
Necessary for successful grafting: a degree of botanical relationship between the stock and scion.

Overcoming environmental and disease conditions (e.g., diseases like gummosis, nematodes, salinity).
Controlling tree size. Stocks can be dwarfing, limiting tree growth.
Overcoming soil problems (e.g., clay soil or sandy soil). Specific stocks are suited to specific soil types.
Speeding up the fruit-bearing stage.
Replacing an undesirable variety with a desirable one without uprooting the tree, utilizing the trunk.
Combining varieties on a single tree to increase variety options.
Propagating plants difficult to propagate using other vegetative methods.

Botanical relationship: Close relationships increase grafting success. This involves producing callus quickly and in sufficient quantities.
Grafting method suitability: Different techniques work better with different plant types.
Compatibility between stock and scion.
Types of Compatibility:
Vital compatibility - Healthy root and scion development; good flower and fruit production. Typically lasts 2-30 years.
Temporary compatibility - compatibility for a specific time period (10-12 years).
Incompatibility - stock and scion do not unite after grafting.

Success rate must exceed 80%.
Monitor the union area of the trunk.
Observe the growth, flowering, and fruiting of grafted trees.
Observe the uniformity of growth between stock and scion.
Observe weather conditions during and after grafting.
Temperature: 27-32°C is ideal; exceeding this can cause desiccation.
Humidity: High humidity is conducive to successful grafting, preventing desiccation of the scion due to high temperatures.
Oxygen: Required for callus, but high acidity can cause issues.
Avoid diseases to the stock or scion resulting from unclean tools.
Ensure the stock from which the scion is taken is clean.

Stock's influence on scion:
Rootstock influences the scion's growth vigor
Affects the shape and growth pattern of the tree.
Influences bud opening timing.
Affects fruit characteristics (e.g., comparing orange on an orange rootstock to orange on a lemon rootstock).
Scion's influence on stock:
A strong scion can lead to a strong stock.
Increased cold hardiness.
Pest and disease resistance (e.g., European grape scion on American grape stocks).

A technique for propagating plants from plant cells containing complete genetic material in a sterile, nutrient medium.
Stages:
Initiation: Excising a part of the plant, sterilizing it, and growing the cells in a MS (Murashige and Skoog) medium.
Multiplication: Transferring the plant and providing cytokinins, preparing the plant for the next phase.
Root Formation: inducing root development using auxins.
Acclimatization: Moving the plant to a light, non-sterile environment with a gradual increase in light exposure.
Medium Preparation: using an appropriate medium for roots.