Fig 1.
Analysis of developing tobacco pollen.
Developmental stages of tobacco pollen according to flower bud size (Buds) was followed by stage determination (DAPI), starch accumulation (Lugol) and IFC analysis at 0.5 and 12 MHz. The stages (I-VIII) represent I, tetrad; II, uni-nucleate, III, late uni-nucleate; VI–VII, binucleate, VIII, mature pollen grains. Scale bars 20 μm
Fig 2.
IFC discriminates between viable and non-viable pollen populations.
Pollen of three different species, cucumber (green), sweet pepper (blue) and tomato (red) were inactivated by heat. The effect of the heat treatment on pollen viability was analysed by IFC and classical FDA staining. A, AmphaSoft dot plots and histograms at 0.5 MHz of fresh (left) and heat-treated (right) tomato pollen populations; B, Temperature-dependent decrease of pollen viability detected by IFC at 12 MHz, * p = < 0.05; C, Correlation of IFC data at 12 MHz with classical FDA staining.
Fig 3.
Heat inactivation of pollen germination and prediction by IFC.
A, Germination of fresh and heat-inactivated pollen samples, cucumber (green), sweet pepper (blue), and tomato (red), * p = < 0.05; B, AmphaSoft dot plots and histograms of fresh (left), 40°C-inactivated (middle), and a mixed pollen population. The arrow points at the fresh and germinating population C, IFC prediction of tomato pollen germination (purple) and in vitro pollen germination (red) after heat-inactivation;