X射线及电子束照射对非洲紫罗兰叶片外植体不定芽再生的影响

采用X射线（电子束能量8MeV）及9MeV电子束对两个品系（Mauve and Indikon）的非洲紫罗兰（Saintpaulia ionahta）组培苗叶片外植体进行辐照处理，研究其组织增殖、芽分化及叶片形态学变化。结果表明，40Gy的X射线照射能使Mauve及Indikon的外植体新鲜组织增殖倍数为27.3和26.3，相同剂量的电子束照射抑制组织增殖能力不如X射线照射，增殖倍数为49．7和27．4。低于20Gy的X射线和电子束照射诱发非洲紫罗兰叶片外植体增殖变化的规律不同于剂量高于20Gy的照射，呈先降低后升高趋势。100Gy的电子束辐照处理使Mauve及Indikon的芽形成率降为3．7％和11.3％，而100Gy的X射线辐照处理其芽形成率分别为7．5％和64．1％。就Mauve而言，60Gy的电子束辐照处理后畸形小苗百分比高达22．2％，相同剂量的X射线辐照处理后为14．8％；而对于Indikon，40Gy的电子束辐照可使畸形小苗百分比升至35．2％，该剂量条件下x射线的百分比仅为5．8％。因此，本研究发现非洲紫罗兰叶片的电子束辐照的诱变效果要优于X射线辐照。电子束辐照非洲紫罗兰Mauve及Indikon叶片组织的推荐最佳诱变剂量为40—60Gy。

Effects of X-ray and electron beam irradiation on adventitious bud regeneration from in vitro leaf explants of Saintpaulia ionahta

Adventitious buds from in vitro leaf explants of two different Saintpaulia ionahta (Mauve and In-dikon) cultivars were irradiated with X?rays or 9 MeV electron beams, the tissue increase, buds differentiation and leaf morphology changes were studied. The results showed that the fresh weight of leaf explants of Mauve and In-dikon irradiated to 40 Gy with the X?rays increased by 27.3 and 26.3 times, whereas they increased by 49.7 and 27.4 times with the E-beam irradiation of the same dose. Changes of fresh weight increase of explants irradiated to less than 20 Gy by both X?rays and electron beams demonstrated a tendency of going down first and then increasing, which differed from those irradiated to higher than 20 Gy. The percentage of bud formation of Mauve and Indikon ir-radiated to 100 Gy with the electron beams were 3.7 % and 11.3 %, respectively, while they were 7.5 % and 64.1 % with the X?ray irradiation of the same dose. The percentage of plantlets with malformed leaves in Mauve irradiated with 60 Gy E-beam irradiation was 22.2 %, while it was 14.8 % with X?ray irradiation of the same dose. For Saint-paulia ionahta Indikon with 40 Gy E-beam irradiation, the percentage was 35.2 %, whereas it was 5.8 % for X?ray ir-radiation of the same dose. The results show that the effect of mutation induction by the electron beam irradiation on Saintpaulia ionahta is better than by the X?ray irradiation. An optimal mutagenic treatment is 40 - 60 Gy irradiation with the electron beams.