快中子辐照对花生胚小叶体细胞胚胎发生的影响

EFFECT OF NEUTRON IRRADIATION ON SOMATIC EMBRYOGENESIS FROM EMBRYONIC LEAFLETS OF PEANUT(Arachis hypogaea L.)

以花生品种鲁花11号成熟干种子为试材,经快中子0、9.7、14.0和18.0Gy辐照后,取胚小叶外植体接种于添加10.0mg/L 2,4-D的MSB5诱导培养基上诱导体细胞胚胎发生。培养4周后,将其转移到添加4.0mg/L BAP的培养基上进行培养。结果表明,快中子辐照处理对胚小叶组织培养及体细胞胚胎发生有很大影响。未处理的对照,体细胞胚(体胚)形成较早,培养15d开始观察到体胚的形成,并且体胚全部是在诱导培养基上直接从外植体形成,几乎未经过愈伤组织。经辐照处理的种子,其外植体只有少部分在诱导培养基上直接形成体胚,而大部分先形成愈伤组织,当转移到添加4.0mg/L BAP的培养基上后,部分愈伤组织进一步形成体胚。体胚诱导率因辐照剂量的大小存在很大差异,随辐照剂量的增加,体胚诱导率呈明显下降趋势。对照体胚诱导率高达80%以上,而辐照剂量由9.7Gy增加到14.0和18.0Gy时,体胚诱导率则由约55%降低到约40%和30%。本研究结果说明,快中子辐照对诱导花生基因突变是有效的,推断14.0Gy为适宜的诱变剂量。

The effect of neutron irradiation on somatic embryogenesis in embryonic leaflet culture of peanut（Arachis hypogaea L.）was studied.The embryonic leaflets separated from seeds of peanut cultivar Luhua 11,which were irradiated at dosages of 0,9.7,14.0 and 18.0Gy,were incubated on MSB5 medium containing 10.0mg/L 2,4-D to induce somatic embryos.After 4 weeks culture,the leaflets were transferred to MSB5 medium supplemented with 4.0mg/L BAP.The embryonic leaflets from the unirradiated seeds formed somatic embryos directly on induction medium containing 10.0mg/L 2,4-D.However,after irradiation most of embryonic leaflets first formed calli,when transferred to MSB5 medium containing 4.0mg/L BAP,some of them formed somatic embryos.Only a few of them formed somatic embryos directly on induction medium containing 10.0mg/L 2,4-D.The somatic embryo formation rates varied with different dosages of neutron irradiation.The percentage of somatic embryo formation declined with the increase of neutron irradiation dosages.When the irradiation dosages were increased from 9.7Gy to 14.0 and 18.0Gy,the percentage of somatic embryo formation declined from about 55% to 40% and 30%,respectively.The unirradiated embryonic leaflets gave a higher rate of somatic embryo formation（above 80%）.The results showed that neutron irradiation was efficient to induce genetic mutation in peanut and the optimum dosage was about 14.0Gy.