Successful achievements in wheat-alien gene introgression by means of chromosome engineering

摘要

In the 20th century considerable crop improvement has been achieved by manipulating genetic variation existing within the cultivated gene pools. For wheat, the most significant advances are associated with the innovative breeding approaches that characterized the so called "Green Revolutions", which greatly contributed to the development and worldwide spreading of high yielding wheat varieties. However, for several aspects the present agricultural scenery appears to be profoundly different from that of earlier times. Due to progressive shortage of available farmland, water and energy reserves, as well as to increased environmental problems, further increments in agricultural productivity will have to be pursued following different strategies than those of the even recent past. In this context, genetic improvement is expected to play a key role. For the genetic approach to be successful, a continuing infusion of new genetic diversity represents a necessary requisite. In spite of its notable achievements, modern plant breeding has seriously threatened the genetic base on which future progress depends. As a consequence, the currently cultivated wheat germplasm has a rather narrow genetic base, essentially derived from intraspecific selection and fixation of a relatively limited set of favourable genes and alleles. However, whereas variability for some traits is limited or even exhausted within the primary wheat gene pool, secondary and even tertiary gene pools represent a wide and yet little exploited reservoir of desirable alien genes that can be incorporated into cultivated genotypes.