温度和水分对不同基因型小麦未成熟胚体细胞胚胎发生以及分化能力的影响

Temperature and moisture influence somatic embryogenesis and somatic differentiation of immature embryos in different genotype wheat

对小麦未成熟胚盾片组织离体再生途径中 ,未成熟胚发育时期以及不同小麦品种的体细胞胚发生能力和体细胞胚的分化能力进行了研究。在所试的 1 4个小麦品种中 ,筛选出具有很强的体细胞胚发生能力和体细胞胚分化能力的 4个品种 :西农 1 376、盐 2号、85+1 - 3和宝丰 72 2 8。为进一步给小麦离体遗传操作打下基础 ,研究还对温度的影响进行了分析 ,通过低温手段解决了胚性愈伤组织随继代天数的延长体细胞胚分化能力快速降低的问题。同时研究还首次分析了干燥处理对小麦体细胞胚转换能力的影响 ,建立起一套高效的小麦离体培养再生体系 ,而且该体系从接种未成熟胚到再生植株移至土壤只需 1 0～ 1 2周时间 。

Wheat ( Triticum aestivum L.) immature seeds were collected after pollination for 12 days and were surface sterilized.The immature embryos were dissected under aseptically condition.The semi transparent immature embryos with length of 1.0~1.5 mm were used for culture on solidified MS medium supplemented with 2.0 mg/L 2,4 D in dark.The ability of somatic embryogenesis of different genotypic wheat was compared.Calluses with somatic embryos were transferred onto solidified MS medium supplemented with 0.1 mg/L 2,4 D and cultured in illumination room for regeneration.Many somatic embryos were differentiated into green shoots after two weeks.At the same time,aboundand roots also were formed in some shoots.Then the shoots were subcultured on hormone free MS medium for another two weeks.In order to accelerate elongation and root formation.The shoots were transferred to half MS medium without phytohormone and the plant in length of 6~8 cm was obtained in 3~4 weeks.The regenerated plants were transplanted in soil and grew in room temperature for 3 weeks.After the plants were vernalizated in 4 ℃ for 1~2 month,matured plants were obtained in greenhouse within two months and seeds were harvested.In 14 different wheat genotypes,Xinong 1376,Yan 2,85+1-3 had very strong ability of embryogenesism,their embryogenesis frequency were more than 90%.The frequency of Baofeng 7228 was relatively low,it was 85%.Temperature had great influence on the maintainence of differentiate ability of the somatic embryo.Differentiate ability of somatic embryose was declined along with subculture time when the temperature was 25℃ while the ability was stable when the temperature was 4 ℃.Furthermore,the influence of dry treatment on somatic embryo differentiation also was analyzed.In this work,a system of wheat immature embryo regeneration in vitro was developed.With this system,only 10~12 weeks were needed from isolation of immature embryos to transplantation the regeneration plants to soil,it can avoid the somatic variations happened in the process of long time cultured.