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SummaryThe effect of a constant (10, 15, 20 or 25°C) or a diurnal maximum/minimum (15/5, 20/10, 25/15 or 30/20°C) incubation temperature on in vitro pollen germination and pollen tube growth in the pistils of two poly-embryonic (‘Kensington’ and ‘Nam Dok Mai’), and two mono-embryonic (‘Irwin’ and ‘Sensation’) mango cultivars was studied. In in vitro experiments where pollen was incubated in a liquid germination medium for 24 h in darkness, little difference was found between pollen germination of mono- and poly-embryonic cultivars. Averaged over the four cultivars, 53.9% of pollen germinated at 10°C, this increased to 76.2% when the incubation temperature was increased to 15°C, thereafter up to 25°C the percentage germination remained stable but germination decreased slightly to 68.2% at 30°C. Similarly, there was no difference in percent germination between cultivars when pollen was incubated under diurnal temperature regimes. Mean pollen germination of all four cultivars was 52.3% at 15/5°C and pollen g...

SummaryThe effect of temperature on inflorescence development and sex expression in two mono-embryonic (`Irwin' and `Sensation'), and two poly-embryonic (`Nam Dok Mai' and `Kensington') mango cultivars was studied. Trees were subjected to natural winter temperatures to induce flowering prior to transfer into controlled environment glasshouse rooms under day/night temperature regimes of 15/5, 20/10, 25/15 and 30/208C for 20 weeks. Inflorescence development did not progress when trees were held at 15/58C. Cooler temperatures (20/108C) delayed the start of anthesis (42.4.d) compared with trees grown at 25/158C (23.d) and 30/208C (16.1.d). At 20/108C, the delay in the start of anthesis was greatest for `Sensation' (55.5.d) and least for `Nam Dok Mai' (25.5.d) while at other temperatures there was little difference between cultivars. The distribution of hermaphrodite flowers within the inflorescence was independent of temperature with the highest percentage found in the apical half of the inflorescence. There ...

The viability of kangaroo paw pollen (Anigozanthos manglesii) was estimated by germination in vitro and by fluorescence and the more reliable method was then used to assess the effect of storage conditions on pollen longevity. Pollen germination was more accurate than staining for pollen of low and intermediate viability levels. Effective storage could be achieved in a number of ways depending on the duration required. Dehydrated pollen retained viability longer in storage than did hydrated pollen. Pollen from intact anthers could be stored for up to 5 weeks at room temperature with 50% or better germination provided it was stored on silica gel. Pollen isolated from anthers and stored at 2°C had reduced viability in comparison with that stored at room temperature or at ‐80°C. Pollen stored at ‐196°C lost only 5% viability after 20 weeks and presumably this would be the most suitable method for long term storage for breeding or conservation purposes.