Alternative explanation: independent assortment
Many crop species have two sets of chromosomes (i.e. they are diploid): one set inherited from the mother (e.g. the red chromosomes 1 and 2) and one set inherited from the father (the blue chromosomes 1 and 2). These are depicted in the figure below. Chromosome 1 from the mother and Chromosome 1 from the father are called homologues: they carry the same types of genes, but they can carry different alleles for those genes. A might be for flower color, A giving red flowers, a white, and B may be for hairiness of leaves, b being glabrous. In this example, a situation with two homozygous parents is shown.
Each chromosome consists of two chromatids that are identical up to the beginning of the meiosis, in which the gametes are formed.
During formation of sexual haploid cells (gametes) the chromosomes of each homologous pair are randomly distributed over the gametes, in such a way that each gamete receives one copy of each chromosome (so one of the homologues). For example, one gamete can contain Chromosomes 1 and 2 from the father, another can receive one from the mother and the other from the father, etc. Therefore, genes located on different chromosomes are inherited independently from each other: they are unlinked. Unlinked loci will show a recombination frequency of about 50% consistent with random assortment
Not all plant species are diploid and even within a species different ploidy levels can occur. In tetraploid species, e.g. each chromosome is present in four copies (4n): two from the mother and two from the father. In a hexaploid (6n), three from the mother and three from the father.
Test yourself and match the ploidy level with the number of chromosomes in a normal cell.