IV.2. Trisomics and aneuploids.
Primary trisomic series have been produced in several varieties of barley (Tsuchiya 1969. Genetica 40:216-232). Several complete or incomplete sets of trisomics have been received by the coordinator. Table 1 contains the list of available trisomic stocks. The trisomic series in Hordeum spontaneum has not been increased recently.
Seven telosomic trisomics (telotrisomics) have been isolated from various sources as shown in Table 2. The characteristics of those telotrisomics are reported in III.30, BGN. Vol. l.
Barley workers who want to use trisomics and other aneuploids should mention the purpose or type of work to be conducted. Some trisomic types are not fertile enough to get sufficient number of seeds for some experiments. However, hybrid derivatives are highly fertile and easy to handle in many cases. If you plan to use trisomic stocks in genetic studies or linkage analysis, trisomic plants of hybrid derivatives will be adequate for that purpose.
Another thing to be pointed out is the cytological technique to be used. Since trisomic studies are cytogenetic work, chromosome study is a prerequisite. Particularly in the case of linkage studies with trisomic it is necessary to handle a large number of plants in a fairly short period of time with accurate identification of trisomic plants.
It is suggested, therefore, that one should develop or become familiar with the cytological technique involved before he starts a cytogenetic study with the use of trisomics and other aneuploids. Please indicate your capability of handling the chromosomes when you request the seeds of trisomics.
Table 1. Available stocks of primary trisomics in barley. (p. 81)
Table 2. Available stocks of telosomic trisomics in barley.
Limited amounts of seed of the primary and telosomic trisomics are available upon request from T. Tsuchiya, Department of Agronomy, Colorado State University, Fort Collins, Colorado 80521, U.S.A.
