Natural methods of vegetative propagation of fruit and berry crops

A large group of natural methods of vegetative propagation applied to fruit and berry plants can be subdivided, depending on the part or organ providing vegetative renewal, into two subgroups: propagation by specialized and non-specialized parts.

A characteristic feature of plants of this subgroup is their ability to form specialized organs, by means of which vegetative propagation is carried out under natural conditions and in cultivation.

Propagation by runners. Runners are specialized propagation organs of strawberry, which are annual creeping shoots with long and thin internodes and often reduced leaves. Runners are capable of forming shortened leafy shoots with adventitious roots (rosettes). Each even node of the runner ends in a rosette – a new young plant.

Propagation by stolons. Like runners, stolons are specialized propagation shoots. However, the specialization of stolons is less pronounced. They, as a rule, bear leaves of standard median formation, but adventitious roots are formed at each node. The stem part of the stolon usually dies off by the end of the growing season or after overwintering, and the connection between the mother plant and the daughter plant is broken. The stem part of stolons may not die off, and in this case, it is often difficult to determine the boundary of the individual. Cranberry, dwarf cornel, cloudberry, etc., propagate by means of above-ground prostrate stolons.

Apomictic propagation. Apomixis (from the Greek apo – without and mixis – mixing) is a highly specialized method of vegetative propagation, in which a new daughter organism is formed in fruits as a result of mitotic division of somatic cells of the ovule or from an unfertilized egg cell without the fusion of gametes. Apomixis is widespread among angiosperms. Among fruit crops, it is found in citrus, fig, raspberry, strawberry, etc. For individual species (raspberry, many citrus), the ability to apomictic propagation is a permanent hereditary trait; in other species, it manifests itself accidentally, facultatively, depending on environmental conditions.

Propagation by tip layering. This method of propagation is characteristic of blackberry. An arcuate blackberry shoot, upon contact with the ground, forms a bud in the upper part, in the tissues of which plastic substances are deposited. Then this bud takes root: adventitious roots emerge at the point of contact between the bud and the soil surface, quickly growing into the ground. Adventitious roots in blackberry are pulling, or contractile. After the roots have entered the soil, the following occurs:

As a result of the contractile activity of the roots, the apical bud of the shoot is pulled into the ground, and only after this does it begin to grow and a young plant is formed. This method of blackberry propagation is widely used in fruit growing, and in its natural habitat, tip layers are often called walking shoots.

Plant propagation by non-specialized parts. Non-specialized parts and organs of a plant that serve the purposes of vegetative propagation are usually not separated from the mother plant under natural conditions.

Propagation by root suckers – shoots. This method of vegetative propagation is characteristic of many crops. A root sucker is a shoot that has developed from an adventitious bud that arose endogenously on the roots.

Sea buckthorn, raspberry, cherry, cherry plum, plum, sloe, common quince, etc., are propagated by root suckers.

The apple tree, cultivars Yandykovskoye, Mamutovskoye, Chulanovka, etc., propagates well by root suckers (shoots). Own-rooted trees of the Yandykovskoye apple cultivar enter into fruiting in the third or fourth year and produce high yields. Root suckers are formed on the roots from adventitious buds and are adventitious in origin. They should be distinguished from suckers that develop from stem proventitious buds. Thus, in hazel, currant, and raspberry, on the underground, long-living stem part (vertical rhizome or xylopodium), due to the natural change of above-ground axes, dormant buds awaken with the formation of new renewal axes. Such suckers are stem-derived, from proventitious buds. A special case of stem-derived suckers is stump sprouting, which arises from dormant buds on perennial axes after the complete removal of the above-ground part of the tree.

Figure 2 – Plum propagation by root suckers (shoots): a – mother plant with root suckers; b – detached nursery plant.

Particulation (from the Latin – particularis – separate) is a natural method of vegetative propagation, consisting of the decay of the mother plant into several daughter plants with their own perennial axes and root system, capable of independent existence after separation. Among fruit crops, particulation is found in strawberry, raspberry, currant, gooseberry, etc.

Particulation and bush division

Particulation is a weakly specialized method of natural vegetative propagation in higher plants. In natural conditions, this mechanism most often manifests itself upon the onset of extreme, stressful environmental factors. In practical fruit growing, bush division is based on this biological principle — a method traditionally used for the propagation of berry shrubs.