Plant breeding: inbreeding and hybridization
Mendel's law in action
The main methods of plant breeding are rarely used in pure form. More often combine several. Which ones depend on the method of propagation of plants and on what selection is used - mass or individual. When plants are selected for cross-pollination, mass selection is preferred. After several generations, the desired feature or property becomes more pronounced. A new variety appears. But it is genetically heterogeneous, therefore, at certain intervals, the selection is repeated. Selection of plants of pure homozygous lines gives the result only with individual selection. ATThe first generation material consists of half of heterozygotes and half of homozygotes. The law of Mendel ensures the appearance in the eighth generation of one hundred percent homozygosity. Features of plant breeding in this way are that with an exceptionally high purity of the desired traits, vitality and fruiting are sharply reduced.Further improvement of the specified properties is carried out by the method of hybridization. Breeders get a new material for the new selection - plants that are significantly superior to their parents in cultivated traits and unite all their viable prevailing genes. This effect is also called heterosis. To consider all the methods by which plants are selected, within the same article, is an impossible task. We give only the most illustrative example of hybridization - the rose.
Miracle of Breeding - Queen of Flowers
This method is used for breeding new varieties of both agricultural and ornamental plants. Nearly twenty thousand modern varieties of garden roses are also the result of hybridization. What did plant selection give to this once wild, homely flower? What newly acquired properties made a rosethe queen?
- Spreading. Thanks to her, varieties such as Etoile d’Oland, Golden Emblem, Madame Bush, Radiani, Talisman, have firmly established themselves in flower beds and decorative terraces.
- Scent. Even the most beautiful flowers lose their charm if they have no smell. In the market, they usually sell them.A woman is so pleased to take a bouquet, smelling intriguing musk or damask sophistication. To give her this pleasure, you need to give Tavrida, San Fernando, Leniniana, Miranda, Oktyabrina, the Pink Pearl. These fragrant varieties are usually used in bouquets.
- Miniature. But the flowers should not only smell. The bride, for example, relies a bouquet of white roses, but it should be small. And then specially bred miniature varieties help out - Baby Gold Star, Beau-Peep, Midget, Cinderella, Roletiya Rose.
- Other properties. Strong-growing floriferous roses of floribunda are created for hedges, for arches and arbors there are curly Elegance, Red Lighthouse, Albertine, Rosy Novost, Golden Glou, for shtambov - weeping varieties. By nature, the rose is a heat-loving plant, but in this respect selection also provides a choice: cold-resistant species - for the north, heat-resistant species - for the south. Here is a miracle flower created by man.