A new method of analyzing cotton (Gossypium hirsutum L., 2n=4x=5) pollen fertility, based on fluorochrome diacetate (FDIC), was recently reported and shown to be highly effective for detecting heterozygosity for simple and compound chromosome translocations. Breeding and usage of other types of cytogenetic stocks of cotton will be facilitated if their pollen fertility can be analyzed with similar facility and reliability. To investigate the potential application of the fluorochrome reaction (FCR) method to chromatin-deficient types of G. hirsutum, we analyzed available monosomics and monotel;disomics in two environments (field and greenhouse), using + reps per deficiency type, and sub-samples of ca. 300 pollen grains per rep. Only pollen normal in fluorescence intensity, distribution and grain shape were classified as fertile.

Data were analyzed before and after arcsine transformation. Results from the chromatin-deficient types differed from results obtained previously from translocation stocks. Environmental and genotype-by-environment effects were relatively strong. Certain monotelodisomics were especially susceptible to environmental effects; flower-to-flower variation occur in the field, and can cause sampling problems. Generally, the monosomics had lower fertility than either respective monotelodisomic. Based on our data, most monosomics and monotelodisomics have an upper 95% confidence limit lower than 95% pollen fertility (normal); and, most monosomics have an upper 95% confidence limit lower than 47.5% pollen fertility. The results also indicate that certain chromatin deficiencies have significant sporophytic effects, otherwise pollen fertility would expectedly not fall significantly below 47.5%. For certain chromatin-deficient types that are relatively difficult to identify phenotypically, or for which corroborating information is desired, the FCR method can facilitate identification of chromatin-deficient progenies. This work was supported in part by the Texas Agricultural Experiment Station.