Use of Cytoplasmic Male Sterility, Compared to Hand Emasculation, and Translocations for Chromosome Analysis in Sorghum vulgare Pers¹

Abstract

Results obtained after use of a cytoplasmic male‐sterile restorer gene system in testcrosses with translocations for chromosome analysis were compared with those from testcrosses after hand emasculation. The use of male‐sterile cytoplasm was relatively easy and less time consuming, thus allowing production of large numbers of progeny and an accurate estimate of linkage intensity.This variation in methodology may have application with other self‐pollinated crops where cytoplasmic male‐sterile restorer gene systems and transloeation stocks exist.Using this scheme the linkage groups T231(13.06±l.1)‐ Dd and T396(5.0±0.6)‐Yy were found, and the possible location of these markers was discussed. The establishment of the chromosome complement and male sterility of MSCK60 as a standard for chromosome analyses in sorghum was proposed.

Rate of crop‐weed hybridization in Sorghum bicolor × Sorghum halepense is influenced by genetic background, pollen load, and the environment

“…Diploids observed in the progeny were likely the result of S. bicolor pollen in the experimental area from either outside sources or sterility breaks that can occur even at individual floret levels (Papathanasiou & Lessman, 1969 ). Field observations of a sub‐sample of the diploid progeny showed a S. bicolor phenotype and thus, the diploid progeny data were excluded from the calculation of outcrossing frequency.…”