Wheat Family Biological Systematics (Volume 2)

Author: Yan Ji, Yang Junliang
Publisher:
Publish Date: 2004-05-01
Features: In the genera of Hordeum and Taeniatherum included in this book, there are very strong specific genetic effects in heterosis and sexuality, which must be taken into account when performing systematic analysis. For example, in Chinese wheat landraces, there are some containing four pairs of high- genes, namely kr1, kr2, kr3, and kr4. If this material is hybridized with rye, their seed-setting rate can reach over 95%, suggesting no reproductive isolation. However, the new chromosomes do not pair during meiosis in the offspring, and the hybrids remain sterile. In the genus Taeniatherum, Taeniatherum asperum has evolved strict self-pollination under extreme arid ecological conditions through natural selection, leading to the selection of a special genetic system. This results in possible incompatibility between different populations, causing high intraspecific reproductive isolation. However, their morphological characteristics and chromosome types are identical. Although these are some extremely rare special phenomena, they are indeed objective realities that we need to pay attention to. Such special phenomena will be encountered in this volume.