Читать книгу Principles of Plant Genetics and Breeding - George Acquaah - Страница 368

Certain specific crosses between cultivated and wild species are known to produce haploids. Well‐established systems include the interspecific crosses between Hordeum vulgare (2n = 2x = 14, VV) × Hordeum bulbosum (2n = 2x = 14, BB), commonly called the bulbosum method, and also wheat × maize crosses. The bulbosum method is illustrated in Figure 7.1. The F₁ zygote has 2n = 2x = 14 (7 V + 7B). However, during the tissue culture of the embryo, the bulbosum chromosomes are eliminated, leaving a haploid (2n = x = 7 V). This is then doubled by colchicine treatment to obtain 2n = 2x = 14 VV.

Figure 7.1 Generating haploids in barley by the bulbosom method.