白兰瓜组织培养中染色体不稳定性的研究

Study on Chromosome Unstability in Tissue Culture of Cucumis melo var Inodorous

白兰瓜体细胞染色体数为2n=2x=24.其子叶经诱导、活化、脱分化,分化形成了再生植株.对这一全过程进行了细胞学观察,结果表明:(1)外植体:2n=24的细胞达90%以上,有6.5%的多倍体;(2)诱导期:切口处大量细胞被启动,出现各种类型的无丝分裂;(3)脱分化期:细胞分裂活跃形成大量的愈伤组织,并伴随着各种类型的染色体数目和结构的变异,这时期畸变率达到最高峰;(4)分化期:愈伤组织上分化形成大量绿色芽点,其中正常二倍体细胞的比例明显增加,畸变率降低;(5)再生植株:二倍体细胞已接近80%,但存在17.5%的多倍体细胞.

The chromosome number of somatic cell-in Cucumis melo var Inodorouswas2n=2x=24.Regenerated plants were formed by cotyledon under inductionand culture on differentiated medium.Cytological observation showed:2～5 days after inoculation,most cells were promoted in cutting,various amitoses were observed:10-15 days after inoculation cuttlation,a good great number of calli were found,cells rapidly proceeded tomitoses,but variation of various chromosomal structure and number,cameabout,aberration rate being the highest 20～25 days after inoculationfrequency of cell division reduced,but variation of chromomsomal numberand structure still existed;40～50 days after inoculation,diploid cells in-creased and aberration rate dicreased in differentiated tissue;Regenera-ted plant(50 days after inoculation),most cells(about 80%)containeddiploid,while the polyplord and aneuploid only were in the minority.