Temperature-stress Pretreatment in Barley Anther Culture

Abstract

Methods of pretreating anthers at different temperatures prior to culture have been tested, with respect to pollen-callus production and plant regeneration, in Hordeum vulgare cv. Sabarlis. For callus production, pretreatment of excised spikes (in sealed Petri dishes) was more effective than pretreatment of excised tillers (in water or in polythene) at both 4 and 25 °C. Pretreatment of individual anthers at these temperatures was deleterious. Greater callus yields resulted from pretreatment at 4 than at 25 °C, both for spikes and tillers, 3–5 weeks being required for maximal yields at 4 °C and 3–5 days at 25 °C. At 4 °C, a shorter pretreatment was required for spikes than for tillers. Pretreatment of spikes was also more effective at 4 than at 7, 14 or 20 °C. Pretreatment of individual spikelets at 4 °C was as effective as that of whole spikes. For plant regeneration, calluses derived from pretreatment of spikes were more effective than those derived from pretreatment of tillers. More plants resulted from pretreatment at 4 than at 25 °C, both for spikes and tillers. Maximal pretreatment times for plant regeneration generally exceeded those for callus production. Following spike pretreatment at 4 °C the maximum for plant regeneration exceeded that for callus production by about 2 weeks. With this optimal pretreatment approximately 60 per cent of the calluses gave rise to plantlets. Among this 60 per cent, for every three calluses giving albinos, two gave green plantlets, equivalent to five green plantlets on average for every 100 anthers (= two spikes) cultured. The ratio of green to albino plantlets was lower for all other pretreatments.