籼稻不同品种成熟胚的组培发育特性及其超微结构的观察

Comparison of Ultrastructure of Callus Induction in Indica Rice With Different Callus Induction Rates

以3种籼稻成熟胚为外植体,接种于愈伤组织诱导培养基(M8+30 g/L蔗糖+8 g/L琼脂+2 mg/L 2,4-D+2 mg/L 6-BA+1 mg/L ABA+0.5 mg/L KT+1 mg/L NAA),记录其愈伤的出愈率,统计分析表明其出愈率有显著差异,并分别取接种9 d、15 d时不同材料的愈伤组织观察其不同诱导天数下超微结构的变化,并记录其愈伤过程中的褐化率.结果显示,3种水稻材料在相同的诱导时间下细胞的发育阶段不同:扬辐籼6号的愈伤组织细胞发育较快,较早地进入了成熟阶段;而恢76愈伤组织细胞则发育较慢,较长时间仍然处于分生阶段;黄华占则发育更慢.可见,不同籼稻出愈率和分化的高低主要与愈伤组织细胞发育速度的快慢、生理功能的强弱、以及其衰老的程度有密切关系.而褐化,不仅与黑色物质聚集早晚有关系,而且与愈伤组织细胞中液泡的发育有着密切关系.通过调高培养基中细胞分裂素类的含量,有利于提高其出愈率.

Mature embryos from 3 Indica rice varieties as explants were implanted in the induction medium（ M8＋30 g/L Sucrose＋10 g/L Agar＋5 g/L Sorbitol＋2 mg/L 2,4-D＋2 mg/L 6-BA＋I mg/L ABA＋0.5 mg/L KT＋I mg/L NAA） and the callus inductivities of these materials were different significantly at 0.01 level,respectively. At the same time, the callus incubated for 9 d and 15 d were observed by a transmission electron microscope, and the callus＇ browning rate was recorded at the same time. The results showed that the 3 rice materials developed differently at the same induction period. The callus cells from Yangfuxian 6 developed fast, while those from Hui 76 developed relatively slow, and the de- velopment of callus cells from Huanghuazhan was the slowest. The performances in callus uhrastructure were also consistent with their cell development periods. It suggested that the callus induction in [ndica rice had close relation with their cell development rates, physiological functions and senescences as well. The callus browning was also related to the accumulation period of some black substance and the development of their vacuoles. The rate of callus induction in Indica rice would be increased by adding cytokinin in medium for callus induction.