II.31 Male transmission of telocentric chromosome in four telotrisomics.
T. Tsuchiya. Agronomy Department, Colorado State University, Fort Collins, Colorado 80521, U.S.A.
Lack of or extremely low pollen transmission of the extra chromosome in the primary trisomic is one of the disadvantages in the use of trisomics in genetic studies of barley. Because telocentric chromosomes appear to have less morphological effect it has been assumed that there may be some pollen transmission. A high frequency of mono-telotrisomic plants and the occurrence of ditelotetrasomic plants in the progeny of the selfed plants with 2n = 14 + telo 1S supports the above-mentioned assumption at least in telo 1S.
Crosses were made between diploid as the female and telotrisomics as male and the chromosome number of the F1 hybrids was counted with the results given in Table 1.
The results indicate that there is pollen transmission in all four telotrisomic
types in very low frequency. Primary trisomics, haploids and even triploid
plants also were obtained in this cross.
Reports II.29 (P. 58) through II.39 (P. 66) by T. Tsuchiya and coworkers are based on the results of researches supported partly by NSF Research Grant GB 4482 X.
