摘要
用石蜡切片技术对溪蜜柚 (Citrus grandis cv.Guanxim iyou)和度尾蜜柚 (C.grandis cv.Duweimiyou)自交和互交胚珠发育进行了比较观察。溪蜜柚的自交授粉后胚珠发育有 2种不同情形 (I型和 II型 ) , 型在授粉后5 d的珠心组织细胞有变形现象 ,接着胚囊萎缩 ,但外珠被能生长发育到 5 0 d左右 ; 型受精后胚乳发育异常 ,种子不能发育。度尾蜜柚自交胚囊中胚乳没有出现 ,在授粉后 35 d左右珠心组织和囊腔同时萎缩。互交胚珠发育正常 ,成熟果实有籽。表明两品种是自交不亲和的 ,导致了果实无籽。但两者的识别反应和阻抑部位不同 ,溪蜜柚 I型可能出现在受精前 , 型出现在受精后 ,而度尾蜜柚自交花粉管可能没有进入胚囊 ,是一种受精前的障碍。瘪籽的大小与不亲和障碍发生的时期有关。实验为进一步研究两品种的自交不亲和性遗传机理提供了实验证据 ,将有助于解决由于果实无籽导致的汁胞粒化、裂果、裂瓣等品质问题。
The development of ovule was studied after self- and cross- pollination of Citrus grandis cv.Guanximiyou (GXM) and Duweimiyou (DWM) by paraffin section.GXM after selfing showed two ovular developmental patterns (Type I and TypeⅡ).In Type I,nucellar cells were deformed 5 days after pollination (ADP),followed by the atrophy of embryo sac,but outer integument continued to develop for 50 ADP;in TypeⅡ,endosperm developed abnormally and eventually aborted.DWM after selfing showed endospermless.Nucellar cells and embryo sac simultaneously atrophied 35 ADP.The development of ovule in crosses between GXM and DWM was normal and result in normal seed formation.These results demonstrate that GXM and DWM are self-incompatible,which is the main reason for seedless fruit.The recognition response and inhibition process occur in different development stage, before fertilization in Type I and after fertilization in Type Ⅱ,respectively.In contrast,self-cross pollen tubes in DWM are unable to reach embryo sac with self-incompatible reaction occurred only before fertilization.It appears that aborted seed sizes are related to the time of self-incompatible reaction.In addition,our results will facilitate investigation on the genetic basis of self-incompatibility in Citrus and provide solutions to juice sac granulation,dehiscent fruit and cracked valve often associated with seedless cultivars.
出处
《武汉植物学研究》
CSCD
2002年第6期409-412,T005,共5页
Journal of Wuhan Botanical Research
基金
福建省教育厅科技计划项目 ( K0 2 0 6 3)资助。
关键词
胚胎发育
GUAN溪蜜柚
度尾蜜柚
自交
互交
胚珠发育状况
比较
Citrus grandis cv.Guanximiyou
Citrus grandis cv.Duweimiyou
Self-cross
Mutual-cross
Embryo development
