Mitochondria and chloroplast contain DNA that in cotton is always inherited through the maternal parent. This organellar genetic material is responsible for maternal effects including, but not limited to, cytoplasmic male sterility. Vesta Meyer (2) introgressed into upland cotton (G. hirsutum) the cytoplasms of seven Gossypium species including G. barbadense, G. tomentosum, G. herbaceum, G. arboreum, G. anomalum, G. longicalyx, and G. harknessii. All of these were subsequently backcrossed by Mahill et al. (1) into G. barbadense carrying the semigamy trait (3).

Five additional cytoplasms have now been introgressed into semigamous G. barbadense. These include the cytoplasms of G. mustelinum, G. darwinii, G. sturtianum, G. davidsonil, and G. trilobum. The tetraploids were crossed directly to cultivated cotton; an upland germplasm line containing the G. sturtianum cytoplasm was obtained from A. A. Bell who made the initial crosses; G. davidsonii was hybridized with G. anomalum, treated with colchicine, then crossed with Lee's D3-compatible G. hirsutum before backcrossing; G. trilobum was hybridized with G. hirsutum, the hybrid treated with colchicine, the@backcrossed through the aneuploid series to the tetraploid level. Each cytoplasm is in at least BC⁴ with AD(2) Sev(7) at the tetraploid level. Due to the very poor 1989 cropping season in Fayetteville, AR, seed will not be available for distribution until the end of the 1990 season.