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Interspecific hybrid between the two species of the
genus Taeniatherum of the tribe Triticeae Sadao SAKAMOTO National Institute of Genetics, Misima, Japan The genus Taeniatherum comprises two diploid annual species (2n=14), Tn. asperum (SIMONK.) NEVSKI and Tn. crinitum (SCHREB.) NEVSKI, distributing widely from Central Europe to Central Asia. In 1965 a strain of Tn. asperum (strain no. 7065) collected at Pul-i-Khumri, Afghanistan, was crossed reciprocally with a strain of Tn. crinitum (no.7064) found at Karaji, Iran. Those two strains were collected by the members of the Kyoto University Scientific Expedition to the Karakoram and Hindukush in 1955 (SAKAMOTO and MURAMATSU 1965). Only three F1 plants, one from Tn. asperum x Tn. crinitum and two from the reciprocal combination, were obtained in 1966. F1 plants showed vigorous growth and marked heterosis was observed in the number of tillers, plant height, and length of top internode, flag leaf and spike. However, the number of spikelets per spike was intermediate between the parents. Chromosome pairing observed from temporary slides only in 18 MI cells of PMC's of the F1 varied between 7II, 6II+2I, 5II+4I, 1III+2II+7I, 1IV+5II and 1IV+4II+2I at the frequency of 9, 1, 3, 1, 2 and 2 respectively. Average chromosome pairing per cell was 0.2IV+0.1III+5.8II+1.9I. Pollen fertility of non-dehiscent anthers of the F1 was very low (0.2-0.5%) and no seeds were obtained at maturity. From these observations it is concluded that the diploid species of Taeniatherum contain very similar but structurally differentiated genomes. Literature SAKAMOTO, S. and M. MURAMATSU 1965. Morphological and cytological studies on various species of Gramineae collected in Pakistan, Afghanistan and Iran. Results of the Kyoto University Scientific Expedition to the Karakoram and Hindukush, 1955, Vol.1: 119-140. (Received January 27, 1969) |