Этюды в области гибридизации, иммунитета и трансплантации растений

tfeed firm and had no passport. It was supposed that this wheat comes from Persia. This new species differed from soft wheats through several morphological characters and through chromosome number. This species was termed Tr. persicum. This name is not correct- since in Iran this species is unknown. In 1921 for the first time we found—not in Iran but in eastern Georgia—great expansions of sowing areas of various kinds of this wheat. It appeared that this was an old aboriginal culture from moun­ tainous Georgia. This wheat was locally called «Dika». Thorough morphological, geographical, anatomical and cytological studies of this wheat were carried on by us. We gave the first di­ agnosis of this new species, selected and described the first four bota­ nical varieties. A ll these data we published in 1923. Later on, it appeared that Triticum persicum is cultivated in Daghestan, Armenia and eastern Turkey. Without its native land (Georgia) this wheat is resistant to Erysiphe, graminis. However, in 1924 we showed that near Tbilissi, Tr. persicum is sometimes liable to the Erysiphe graminis. Having discovered and studied two new wheat species — each not fully genuine — becrossed these two species. It is noneworthy that in shorogenesis both these species possess fourteen chromo­ somes (by 28 chromosomes in the somatic cell). Both these species are summer kinds. The cross of two species resistant to fungus diseases promised to give immune hybrids. If the hybrids were even practically inva­ luable they might, nevertheless, be.used in «bridge» crosses. Iji the literature we read that almost all the hybrid combinations with Tr. Timopheevi are characterized by sterile F s. This is cau­ sed by the specific genom of this wheat species. Thus, in order to obtain a relatively constant and fertile hybrid, we artificially doubled the chromosome complex in the meristematic cells of the germinating embryos of the grain of F x hybrids. r It should be mentioned that with rare exceptions, the amphidi­ ploids of cereals have given nothing in practical respect. However, amphidiploids are valuable because they reestablish fertility in remote hybrids and give comparatively stable inheritance. Owing to this / we started doubling the chromosome complex in Fj hybrids produced from crosses between Triticum persicum Vav. var; fuliginosum .Zhuk ( Q ) X Triticum Timopheevi Zhuk, var. typicum Zhuk (<$). One day old F t seedlings were treated with 0,02 per cent colchicine solutions for 36 hours (not deeply immersed). During the day, the cups containing the solution with seedlings were irradiated by a small electrical stove. After being rinsed for eight hours, the seedlings were planted directly into the soil (beginning of May, 1939). In the number of grown and ripe plants, there were chimaeras containing on one side fertile ears and tetraploid embryos, and on the other side sterile ears. ’ / Two plants were complete amphidiploids of almost normal ferti­ lity. Owing to chromosome duplication, the plants had vigorous - 39 - Электронная Научная Сельскохозяйственная Библиотека