An estimation of the time constant of movement detectors

✍ Scribed by A. Guo; W. Reichardt

• Book ID: 104742203
• Publisher: Springer
• Year: 1987
• Tongue: English
• Weight: 226 KB
• Volume: 74
• Category: Article
• ISSN: 0028-1042
• DOI: 10.1007/bf00366085

✦ Synopsis

6], and ethylene has been shown to stimulate pollen germination and tube growth in some plant species [2,3,8]. The precursor for ethylene, aminocyclopropane-l-carboxylic acid (ACC), is also present in pollen [12]. If a volatile is involved in accelerating pollen germination in excised flowers, flower morphology would be important in making the volatile available to the pollen. The keel of legumes forms a closed compartment surrounding the anthers and stigma, which could entrap moisture, ethylene, or CO2 [9], all components previously linked with enhanced pollen germination. We found that pollen germination was also greatly accelerated in excised flowers of other legumes, lima bean (Phaseolus lunatus L.) and soybean (Glycine max (L) Merrill), but not in flowers of plant species with more exposed anthers, tomato (Lycopersicon esculentum Mill.), pepper (Capsicum annum L.), cucumber ( Cucumis sativus L.), and melons (Cucumis melo L.). While about 75% of the pollen germinated within excised flowers held in a humidified environment, only about 15% of the pollen attached to anthers that had been separated from the flower, and none of the pollen freed from anthers, germinated when held in a similar humidified environment. This suggests that moisture needed for hydration of bean pollen is primarily obtained from maternal tissue and not from the atmosphere. Pollen germination in excised flowers is now being used for laboratory and field screening for stress-tolerance in beans and other legumes.