Development and characterization of Triticum aestivum–Aegilops kotschyi amphiploids with high grain iron and zinc contents

Synthetic amphiploids between Triticum aestivum (AABBDD) landrace Chinese Spring (Ph I ) and cultivar WL711 with different accessions of Aegilops kotschyi (UUSlSl) were developed through colchicine treatment of sterile hybrids. The F1 hybrids and amphiploid plants were intermediate between the parents for plant morphology and spike characteristics. Meiotic metaphase chromosome analysis of the F1 hybrids (ABDUSl) showed the expected chromosome number (35) and very little but variable homoeologous chromosome pairing. The amphiploids (AABBDDUUSlSl), however, had variable frequency of univalents at meiotic metaphase-I. The SDS–PAGE of high molecular weight glutenin subunits of amphiploids along with the parents showed the presence and expression of all the parental genomes in the amphiploids. The amphiploids with seeds as large as that of wheat cultivars had higher grain, flag leaf and grain ash iron and zinc concentrations than the wheat parents and comparable with those of their Ae. kotschyi parents suggest that Ae. kotschyi possesses a distinctive genetic system for the micronutrient uptake, translocation and sequestration than the wheat cultivars. This could, however, be demonstrated unequivocally only with comprehensive data on biomass, grain yield and harvest index of the Aegilops donors and the synthetic amphiploids, which is not feasible due to their shattering and hard threshing. The use of amphiploids for the transfer of high iron and zinc concentrations and development of alien addition and substitution lines in wheat is in progress.