香梨杂种后代花粉发育类型及其花药的解剖学研究

Pollen Development Types and Anther Anatonomy of 'Xiangli '(Pyrus breschneideri Rehd.) Hybrids

对4个组合35个香梨F1代单株的花粉发育状况进行了考察,并结合花粉量调查对F1代群体的典型单株进行了花药解剖研究。结果表明:(1)香梨杂种后代的花粉发育类型大致可分为3种类型,即正常发育型、少粒空壳型和完全败育型,其中雄性不育类型(少粒空壳型和完全败育型)占到整个杂交后代株系的42.8%。(2)花药解剖观察显示导致花粉空粒化进而完全解体的主要原因是药壁组织的异常发育。推测梨的雄性不育性可能受1对纯合的隐性基因控制,人为杂交导致的基因重组使隐性基因纯合后在杂交后代中高频率表达;同时发现,其花粉发育也受环境影响,树体的营养状况可影响花粉的发育进程。

The anther development of 35 F1 hybrid seedings from 4 crosses of ＇Xiangli＇（Pyrus breschneideri Rehd.） was studied by genetic analysis.Combining with investigation of pollen mass,anatomical observation was conducted in the 12 F1 seedings.The results showed that：（1）there were three types of pollen development：normal,less pollens in empty sac and abortion.Higher rate of male sterile individuals（42.8%） was found in the cross progeny while the parents were male fertile.（2）The developmental anatomical observation revealed the microspore abortion resulted from metabolism disorder of tapetum.It was supposed that pear sterility was possibly controlled by a pair of recessive genes.The expression of the gene with higher frequency in hybrid progeny was due to the purification of the recessive genes by articular cross.At the same time,environment such as tree healthy level also involved in the expression of the sterility.