Effects of γ-rays on diffused-centromeric chromosomes of Drosera falconerii in vitro

概要

論文の詳細を見る
Axenic cultured Drosera falconerii (2n=12) was exposed to γ-rays from Co_<60> at various doses and dose rates to be caused in physiological and cytological conditions. They were commonly stabilized death rate at the 170th day period after irradiation. They showed chromosome aberrations such as gaps, breaks, fragmentations, fusions, quadriradials, pulverizations, sister chromatid exchanges, chromatid separation or ski pairs, and tripolarity at 0.44 Gy/sec. Frequencies of chromosome aberrations were 32, 62, 75 and 100% at 1, 5, 10 and 40 Gy each 0.44 Gy/sec, respectively. Isolation of mutated portions in chimera plant body of D. falconerii caused by irradiation and micropropagation to establish new culture-lines was utilized by transplanting explants of roots and leaves onto 1/2 strength of Murashige and Skoog (1/2 MS) gelrite media supplemented with 1.5% sucrose and α-naphthalene acetic acid (NAA) and 6-benzylaminopurine (BAP) at various concentrations in combination at pH 5.5 ; 80% leaves generated adventitious plantlets at the 100th day period if they were planted on hormone-free 1/2 MS medium ; ca 100% roots generated new roots ; and leaf formation begun at the 180th day period after transplantation onto 1/2 MS media supplemented with 0 and 0.02 mg/l BAP and 0.2, 2.0 and 4.0 mg/l NAA in combination.