Oil tea (Camellia oleifera) is one of the most economically important forest species native to
China. Successful pollination requires pollen grains with high fertility, which directly determines
the cross-breeding success of oil tea. To better understand pollen fertility, pollen viability and vigor
of the interspecific hybrid cultivar ‘DY-4’ (Camellia grijsii ‘Youza 2’ × C. oleifera ‘Huashuo’)
were investigated using staining and in vitro germination tests. Results indicated that pollen viability
was 51.13% and 66.08% by the TTC and FDA staining methods, respectively. The germination
rate was 54.22% when using 1% agar, 100 g/L sucrose, 0.1 g/L H3BO3, 0.03 g/L MgSO4, and 0.01
g/L IAA, which was higher than the control with 1% agar (germination rate = 19.09%). Meiosis
and chromosome of ‘DY-4’ pollen mother cells exhibited abnormal behavior including free or lagging
chromosomes and abnormal spindle orientation. In addition, scanning electron microscopy
showed that ‘DY-4’ exhibited many deformed pollen grains, with a deformation rate of about 16%.
The accumulation of these abnormalities may affect pollen fertility in the cultivar ‘DY-4’. Our current
cytological observation and fertility analysis of pollen of the cultivar‘DY-4’ will lay the foundation
for cross-breeding of oil tea in the future.