THE EFFECT OF TEMPERATURE ON POLLEN FERTILITY AND ANTHER DEHISCENCE OF CYTOPLASMIC MALE-STERILE RYE

Pollen fertility and anther dehiscence of two cytoplasmic male-sterile lines of spring rye (Secale cereale L.), their maintainers, their restorers and the F1 between each sterile and restorer were investigated at three temperature regimes (15/10, 20/15 and 25/20 °C). In a second experiment, the anther dehiscence of five additional sterile/restorer hybrids was investigated at the same temperatures. Anthers of male-sterile plants did not contain pollen grains and were non-dehiscent at all temperatures. Pollen fertility of maintainer, restorer and sterile/restorer hybrids varied with temperatures. All anthers of maintainer and restorer lines were fully dehiscent, but partially dehiscent and non-dehiscent anthers occurred in the sterile/restorer hybrids. Anthers of florets in the upper and lower portions of spikes of the sterile/restorer hybrids were often partially dehiscent or non-dehiscent. Variation among tillers of a plant with respect to this character was low, but variation among plants of a sterile/restorer hybrid was high, suggesting genetic segregation. The classification of an anther as either dehiscent, partially dehiscent or non-dehiscent was directly related to pollen fertility. Better restoration of fertility was obtained at temperatures of 20/15 or 25/20 °C than at 15/10 °C.