A. Indrianto et al., Assessment of various stresses and carbohydrates for their effect on the induction of embryogenesis in isolated wheat microspores, PLANT SCI, 143(1), 1999, pp. 71-79
Isolated microspores of flowering plants can undergo embryogenesis when cul
tured in vitro under appropriate conditions. This process is triggered by v
arious stresses including cold, heat and starvation. We have studied the ef
fects of these stresses on the induction of embryogenesis in wheal microspo
res isolated from freshly cut or cold pretreated tillers. We show that the
stress can be applied directly to microspore cultures, and efficient induct
ion of embryogenesis can be obtained from microspores using a variety of st
resses, namely cold (4 degrees C), heat (33 degrees C) and carbohydrate/nit
rogen starvation. Cold pretreatment of tillers was able to replace stresses
applied to microspores. For the first time we report on embryo formation i
n true ab initio wheat microspore cultures, not requiring any pretreatment
of anthers or tillers prior to culture, in a maltose-containing medium. The
effect of maltose on the induction of wheat microspore embryogenesis was s
pecific and can possibly be attributed to its slow hydrolysis by plant cell
s, exerting starvation conditions early in culture and stable osmolarity of
the medium later on. A comparison of three protocols for the induction of
wheal microspore embryogenesis and plant regeneration has revealed no signi
ficant difference in plant yield, but the ploidy of the plants obtained was
affected. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.