Abstract
Triticum timopheevi cytoplasm has been reported to induce pre-harvest seed sprouting in common wheat. To establish a relationship between T. timopheevi cytoplasm and the expression of α-amylase isozymes, mature and immature seeds from alloplasmic lines of T. aestivum var. erythrospermum (Tve), cv. Chinese Spring and cv. S-615, having this cytoplasm, and their corresponding normal lines, were studied by the disc-isoelectrofocusing method. No variation was found among the lines tested for α-amylase isozyme bands in the cathodic side. Some of the nodic bands always appear in earlier germination stage in seeds of alloplasmic lines than in those of normal lines. Immature seeds, 10 and 17 days after pollination, from all lines show activity of some anodic bands, but 24 day old seeds reveal no activity except in the alloplasmic Tve line that occasionally shows several active bands. Therefore, the regulation of α-amylase expression during seed development is somewhat disturbed by the T. timopheevi cytoplasm, resulting in the lack of seed dormancy and pre-harvest sprouting.
