Fig. 6

Barley anthers fixed, sectioned and stained with toluidine blue to determine flower stage. Florets extracted from the middle of the spike at; a 11 mm spike showing three cell layers and primary sporogenous cells at Zadoks stage 31; b 17 mm spike showing four cell layers and secondary sporogenous cells to pollen mother cells at Zadoks stage 32; c 35 mm spike showing released microspores and tapetum becomes vacuolated at Zadoks stage 34; d 53 mm spike showing microspores becoming vacuolated and middle layer breakdown at Zadoks stage 36; e >60 mm spike before LFE1 showing tapetal breakdown; f >70 mm spike at LFE1-2 showing tapetum breakdown and microspores going through mitosis I. Within the images; tapetum (t), endodermis (en), epidermis (e), middle layer (ml), microspores (m). Scale bar is 0.05 mm