듀럼밀 三染色體 植物에서 剩餘染色體의 細胞學的 行動 및 傳達率

Cytological behavior and transmission rate of extra chromosome in durum wheat trisomics

At first metaphase of PMCs in the trisomics of durum wheat(Triticum durum var. hordeiforme), various configurations of chromosomes with varying number of trivalents representing V shape(75.45%), Frying-pan shape(16.7%), Chain shape(7.06%) and Y shape(0.71%) were observed. The frequency of chromosome configuration of 13Ⅱ+1Ⅲ at first metaphase except for Tri-2B line appeared much less than that of 14Ⅱ+1Ⅰ, which showed the percentage of average number of the 13 trisomics was 45.35% while 14Ⅱ+1Ⅰ showed 52.48%. At first anaphase, chromosomes were separated to 14 : 15 type (14Ⅱ: 13Ⅱ+1Ⅲ) in many sporocytes, while one lagging chromosome (14Ⅱ:1Ⅰ: 14Ⅱ) was observed frequently. Among the selfed progeny of homozygous trisomics, the lowest transmission of extra chromosome was observed in Tri-4A line (15.0%) and the highest in Tri-2B line(40.0%), and the average transmission rate of the trisomic lines was 26.9%. While the extra chromosome was transmitted in all types, the frequency of transmission of the extra chromosome through the pollen had been found to be considerably less than that of the eggs. In either case, the reduction in the transmission rate of the extra chromosome was suspected to be due to the loss of univalent chromosome and functional depression in the aneuploidy gamate at fertilization.