水稻愈伤组织发生褐变的影响因素研究

本文研究了水稻愈伤组织诱导过程中与褐变发生有关的五种影响因系。结果表明,水稻基因型的影响在所研究的诸因系中居首位。水稻不同基因型间愈伤组织发生褐变的褐化率差异很大,品种间最低与最高褐化率可相差6.67倍。培养基的不同pH值对愈伤组织褐变发生也有明显的影响。在灭菌前培养基pH6.0～6.4(灭菌后pH5.6～6.0)范围内,愈伤组织的褐化率最低,而当大于或小于此pH范围时,褐化率则明显上升。培养持续期在1～3周内,愈伤组织的褐化率与褐化指数均随培养期延长而增加。用水预先浸胚处理可增加愈伤组织的诱导率和在一定程度上降低其褐化率。紫外光预先照射稻胚处理也会增加愈伤组织的褐化率,但其影响程度基因型间有很大差异。

STUDY ON THE FACTORS RESPONSIBLE FOR RICE CALLUS BROWNING

Five factors related to the browning occurcncc during the callus induction in rice have been studied. Among the factors studied, gcnotypcs of rice showed the greatest effect. Callus derived from different gcnotypcs had different browning rate and the maxium browning rate was 6.67 times of the minimum, pH values also showed significant effect on callus browning. The browning rate was lowest when the pH values in the culture medium were kept within the vangc of 6.0 to 6.4 before sterilization, and suboptimum pH values led to obvious increasing in browing rate. Within the culture duration of 1-3 weeks, both callus browning rate and browning index increased with prolongation of the culture duration. Prctrcatment by submerging embryos in water helped increase the callus induction rate and reduce its browning rate to some extent. Prctrcatmcnt by exposing rice embryos to extroviolet light also elevated the callus browning rate, but the degree of its influence depended on the genotypcs.