【作者】 魏跃； 贾思振； 颜志明； 王全智；

【机构】 江苏农林职业技术学院农学园艺系；

【摘要】 为创制矮牵牛三倍体种质并对其进行细胞学研究,以矮牵牛二、四倍体为亲本对正反杂交座果率、单果结子数进行比较,对杂交后代进行染色体计数并与双亲进行农艺性状和解剖学比较,采用常规压片法对三倍体减数分裂进行观察。结果表明:(1)以四倍体为母本、二倍体为父本杂交的座果率、单果结子数显著高于反交,是获得三倍体矮牵牛的有效途径。(2)同源三倍体(2n=3x=21)冠幅、主茎粗、萼片宽性状具有较强的杂交优势,可育花粉率为44.7%低于父母亲本,花粉直径大小介于父母本之间具有较高育性,这为初级三体等非整倍体选育奠定了基础。(3)终变期大部分细胞内都出现单价体、二价体和三价体共存的现象,中期Ⅰ和中期Ⅱ出现游离在赤道板外染色体,后期Ⅰ染色体有10/11、9/12、8/1 3和7/14分离方式,并出现姊妹染色单体提前发生分离和丢失染色体,后期Ⅱ有10/10/11/11、9/9/12/12、8/8/1 3/13等分离方式,末期Ⅰ和末期Ⅱ存在落后、丢失染色体和染色体桥现象,四分体期观察到具有1-2个微核的四分体,减数分裂各时期平均约有8.6%的花粉母细胞表现异常。更多还原

【Abstract】 In order to creatautotriploidgermplasm and carry cytology study in petunia,fruit set rate and seed numbers per fruit were investigated and compared between reciprocal crossby using diploid andtetraploid as parent,chromosome number counting andmeiotic observation on hybrids were also carried on,in addition agronomic and anatomical traits were compared between hybrid and parents.The results showed that(1)fruit setting rate,seeds number per fruitwere significantly higher than reciprocal crosswhentetraploidused as the female parent and diploid as male parent in hybridization,this mating type was proved to be an effective way to obtain triploid petunia.(2)growth extention,diameter of main stem and sepal width ofautotriploid(2n=3x=21)had significant heterosis,fertility rate of pollen was44.7%,lower than parents,its size was between its parents,higher fertility of pollen laid a foundation for the trisome formation.(3)Univalent,divalent and trivalent coexisted in the majority of cell in Diakinesis,some chromosomes were outside of equatorial plate in metaphase Ⅰ and Ⅱ,distribution of chromosomes in anaphase Ⅰ had 10/11、 9/12、 8/13 and 7/14 types,sister chromatids dividing beforehand and chromosomes lost also found in this period,distribution of chromosomes in anaphase Ⅱ had 10/10/11/11、 9/9/12/12、8/8/13/13 types,lagged and lost chromosomes,chromosomes bridges existed in telophasel and II,tetrads with 1~2 micronucleus were found,abnormality was about 8.6%in meiosis among pollen mother cell.更多还原