一、杂株类型和形成原因 1.保持系。不育系中数量最多的杂。开花散粉时,开花整齐,颖壳绽开,花丝长且刚劲有力,呈放射状从颖壳里水平伸出肥大花药。花药淡黄色,略一碰动即有花粉散出,开花次日呈黄褐色,形成原因一是田间未去除尽,二是风晒时通过场地、用具混入不育系中。 2.变异株和异品种。株形、叶片、谷粒与不育系略有不同,能产生花粉,繁殖田中不及时拔除,异交结实会产生大量杂株,形成原因最初是繁殖田隔离不严,中稻串粉;也可能是贮运种子时混入共它种子,但花期去杂不及时也会发生串粉,串粉后形成的杂交种,代代出现性状分离及串粉,使杂株总去不干净。 3.半不育株。主要在Ⅱ—32A上有所发现,一个不育系穗子,绝大多数颖花不育(花药瘦小不开裂散粉), First, the type of hybrids and the formation of reasons 1. Maintain the Department. Inbred lines in the largest number of miscellaneous. Flowering loose powder, flowering neat, husky bloom, filaments long and vigorous, radially from the hibiscus level hypertrophy. Anthers pale yellow, slightly touched that pollen emanated, flowering the next day was brown, the formation of the first field is not removed, the second is the wind through the venue when the sun, utensils mixed with sterile lines. Variant strains and different varieties. Plant shape, leaf, grain and sterile lines are slightly different, can produce pollen, breeding in the field is not removed in time, outcrossing will produce a large number of hybrids, the formation of the first reason is the isolation of marshland insignificant, rice stringing; may It is a hybrid seed that is mixed with seeds during storage and transportation. However, when the flowering season is not completed, the hybrid seeds formed after the string powder and string powder are formed. 3 semi-sterile plants. Mainly found in Ⅱ-32A, a sterile panicle, the vast majority of spikelets sterile (anther thin, not cracking loose powder),