水稻花粉白苗的若干特性及其成因的探讨

水稻花粉白苗的再分化所生成的再生植株全为白苗,这说明花粉白苗的形成是不可逆的,可能是基因突变的结果。不同品种或杂交组合的水稻花粉白苗叶片丙酮提取液的吸收光谱相互间显示出了相似性,这种相似性就进而提示突变可能发生在基因组的特定位点上。有可能花粉白苗是质体DNA在花粉的脱分化过程中发生缺失形成的。这种缺失主要影响质体rRNA的合成水平,并不导致蛋白质和叶绿素合成能力的全面丧失。花粉植株细胞中的质体可能是不均一的。

Some Characteristics of the Albino Pollen Plantlets of Rice and Investigation about Its Cause of Formation

Regenerated plantlets were obtained both from green and alhino pollen plantlets by dedif-ferentiation and redifferentiation.The fact that plantlets from albino pollen plantlets contained albinos only indicates the formation of pollen albino is irreversible and may be resulted from gene mutation.The absorption spectra of leaf acetone extracts of rice pollen albinos induced from one species and three hybrids show significant similarities with each other,this suggests that mutation may take place at some specific loci of the genome and do not make the leaves of pollen albinos lose its synthetic power of chlorophyll entirely.In conjunction with the lack of rRNA in the plastid,it is fairly reasonable to assume that mutation may affect mainly the enzymes or corresponding cofactors associating with plastid rRNA synthesis and thus lower the chlorophyll content and related components.There are also clues to indicate that plastids of pollen plant leaves may be heterogeneous.