FALLING NUMBER AND ALPHA-AMYLASE ACTIVITY IN DEVELOPING GRAIN OF ALLOPLASMIC HEXAPLOID WHEAT

Twelve fertile alloplasmic wheat lines, produced by substituting four nuclear genomes of Triticum aestivum into the cytoplasms of T. timococ cum Kostoff, T. timoheevi Zhuk., and Aegilops ventricosa Tausch, were examined for cytoplasmic effects on falling number and alpha-amylase a ctivity during grain development in different environments. Nuclear ge nome, cytoplasm and environment were important sources of variation fo r falling number. In one environment, where the plants were exposed to very hot, dry conditions, the levels and patterns of change in alpha- amylase activity were also significantly affected by the cytoplasm. Th e data indicated that alien wheat cytoplasms might result in useful ad ditional variation in specific environments where sprouting is a probl em.