| On a natural hybrid between Aegilops triuncialis
and Triticum aestivum found in lran and its cytogenetical significance
Hermann KUCKUCK and Gisela POHLENDT Institute of Plantbreeding, Hannover-Herrenhausen, Germany During his activity as an expert for plant breeding in Iran under the " Expanded Technical Assistance Program " of the Food and Agriculture Organization of the United Nations from 1952-1954, the senior author availed himself of the opportunity to collect specimens of Aegilops on a large scale on his excursions through the country. Whereas a survey of the distribution of the various species of Aegilops and their chromosome numbers is planned for one of the forthcoming issues of WIS, this paper is dealing with a natural Aegilops x Triticum hybrid having arisen in a sample of Aegilops triuncialis. This specimen was taken from a locality in Azerbaijan in August 1954, labelled as Nr. 260 c in the order of the author's whole collection; the locality is situated 162 km south from the capital Tabriz on the road to Miani, betiween 47/48 degrees of longitude and 37/38 degrees of Iatitude on 1240 m altitude above sea level. This population of Aegilops triuncialis was spread along the edge of a wheat field; some plants were found inside the field which occurs very seldom. The population was distinguished by plants with white and brownish-black coloured glumes. The wheat field was grown by a population of Triticum aestivum which exhibited a great variation regarding the shape and length of the ears and the colour of their glumes: white, brown, violet. For the first time seeds of this Aegilops specimen were grown in 1954 at the Iranian Experimental Station of Agriculture at Karaj, 40 km west from Teheran. Among 10 plants 3 of them proved to be hybrids. Unfortunately they were discovered too late to carry out controlled pollination. In the following year the stored seeds of the original specimen were resown at the Institute of Plantbreeding in Hannover-Herrenhausen, Germany, which gave rise to another hybrid among 5 true breeding Aegilops plants. The cytological investigation of this last mentioned hybrid plant revealed in the early stage of its development the somatic chromosome numbers approaching the expected 35 (n1=14 and n2=21). There were only small deviations of this number in some metaphases, e.g. 31, 36, 37, 38. But in the later development after the heading period greater deviations of chromosome numbers were observed; it was stated that they were varying from 9 to 50. The first hybrids grown at Karaj after free pollination yielded 72 seeds, which could be classified in 3 groups: |
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