There are different methods to selective breeding crops
1. A plant is first selected by identifying the plant with phenotype of interest, such that good genes combination for desirable trait are picked out. The plant is then allowed to grow and self fertilise or cross fertilise with other plants of similar phenotype of interest. In the F1 generation, the plant expressing the phenotype of interest is picked out to be used as parent for the next generation. This way, desirable traits can be passed down continuously. This method of breeding had been used unintentionally during the past and has led to the many domesticated crops being grown today.
2. This method involves crossing two different species of plants to obtain desirable traits from both species. Hybrid varieties are developed through cross-pollination of genetically compatible trees. Selective breeding using cross pollination has been used since the Neolithic period and is the reason we have the diversified food base that we enjoy today. Peaches, Nectarines, Plums, Apricots, Cherries, and Almonds are all members of the same family of trees, and so they are all compatible. From these trees, different hybrids can emerge: pluots, plumcots, apriums, cherrums, pluerries, nectacotums, and peacotums, to name a few.
3. This is usually done by crossing two members of the same species which possess dominant alleles for particular genes, such as long life and quick metabolism in one organism crossed with another organism possessing genes for fast growth and high yield. Since both these organisms have dominant genes for these desirable characteristics, when they are crossed they will produce at least some offspring that will show ALL of these desirable characteristics. When such a cross occurs, the offspring is termed a hybrid, produced from two genetically dissimilar parents which usually produces offspring with more desirable qualities. Breeders continuously track which characteristics are possessed by each organism so when the breeding season comes once again, they can selectively breed the organisms to produce more favorable qualities in the offspring. The offspring will become heterozygous, meaning the allele for each characteristic will possess one dominant and one recessive gene. Most professional breeders have a true breeding cross (ie AAbb with AAbb) so that they will produce a gene bank of these qualities that can be crossed with aaBB to produce heterozygous offspring. This way the dominant features are retained in the first breeding group and can be passed on to offspring in the second instance.
Hope this helps <3 brainliest will be much appreciated
Subsistence farming – the cultivation of crop plants and the keeping of animals to ensure self-sufficiency – is something states, seed producers, agro chemical concerns, and world trade organizations consider backwards today – inefficient and a cause of poverty in the rural areas of the South.
The two most obvious ones are on the far right, and near the far left. Oceanic lithosphere is descending into the earth's mantle at these places, and being destroyed. ... At convergent boundaries oceanic lithosphere is always destroyed by descending into a subduction zone
