A reproducible in vitro pollen germination medium for recalcitrant cereal rye pollen (Secale cereale L): Effect of tryptone

Abstract

A reproducible in vitro pollen germination medium (PGM)
for cereal rye is reported here using tryptone for the first
time. Rye pollen is very difficult to germinate on nutrient
medium being trinucleate and is classified as recalcitrant
pollen. This study addresses the possibility of testing the
viability of rye pollen within short time (15-20 min) using
pollen germination medium (PGM). The viability of rye
pollen was tested with FDA staining also. The results of
both staining and in vitro pollen germination were found
comparable. In this study, tryptone, a nitrogen source was
used in addition to essential sugar and inorganic salts.
PGM used for rye consisted of 19% maltose, 13% poly
ethylene glycol 6000, 62.5 mgl-1 boric acid, 50 mgl-1tryptone
and 1% agar. During the flowering period, a pollen sterility
of 3-12% was recorded. The PGM showed >93% pollen
germination with intact pollen tubes at 17±1oC and pH 6-7.
This tool would be useful in many pollen biotechnological
aspects such as pollen transformation, overcoming
crossability barriers especially in wheat x rye wide
hybridization etc.