Cytogenetic behaviour and phosphate and potassium content in desynaptic pearl millet

Summary Continued inbreeding by self pollination resulted in a proportion of sterile plants in some families of the inbred line IP 1475 of Pennisetum americanum (L.) Leeke. Cytological examinations of the sterile plants revealed mild to extreme desynapsis and also chromosome fragmentation in some plants. Segregation ratios in the selfed families did not fit into any simple Mendelian ratio; however, in one F₂ family of the cross desynaptic x normal, segregation into 15 normal: 1 desynaptic was observed. Plants from a segregating family were classified as normals, desynaptics with 2–6 univalents, desynaptics with 2–10 univalents, desynaptics with 10–14 univalents and desynaptics with chromosome fragmentation. Estimation of the content of phosphate and potassium from the flag leaves did not reveal significant differences between the five groups of plants.