Cytoplasmic influence on several agronomic traits has been reported for various crop species59. Maternal influence on inheritance of these traits could be because of extra nuclear genes located in chloroplast and mitochondria. It has been proposed that Triticum monococcum (male) genome A combined with Aegilops speltoides (female) B genome to form T. dicoccum and that T. dicoccum AB (female) then combined with A. squarrosa (male) genome D, to form T. aestivum ABD60. The higher specific activity of RuBPC was shown to be associated with the possession of a large subunit derived from the B genome of A. speltoides (female)61,62. In fact substitution of the same nuclear genome into different cytoplasms of wheat (T. aestivum L.) showed that ribulose bisphosphate carboxylase/oxygenase (rubisco) specific activity was consistent with the type of cytoplasm61–63. Cytoplasmic (maternal) influence on the inheritance of photosynthesis and rubisco activity was also observed in Brassica species58.