【作者】 冯建荣；

【导师】 陈学森； 束怀瑞；

【作者基本信息】 山东农业大学 ， 果树学， 2006， 博士

【摘要】 本文为研究杏自交不亲和性强度差异的机理,以自交亲和(Self-compatibility:SC)品种凯特(Prunus armeniaca L.cv. Katy)与自交不亲和(Self-incompatibility:SI)品种新世纪(Prunus armeniaca L.cv. Xinshiji)及其杂交F1代部分杂种为试材,从生理及S-RNase基因DNA、RNA和蛋白水平比较了自交亲和与自交不亲和两种类型差异;对自交亲和和不亲和性杂种后代授粉后花柱蛋白质组进行了比较研究。主要研究结果如下:1.授粉后初期,凯特与新世纪的花粉都能正常萌发、生长,但是在花粉管生长延伸到花柱1/2以后,凯特的花粉管能顺利进入子房,而新世纪的花粉管多数停止向下生长,并发现有花粉管顶端膨大现象,只有极个别能正常生长到达子房;花粉管生长速度受外界环境温度影响较大,在活体中花粉从柱头萌发到花粉管进入子房,时间可以从24-72 h不等,生长速度越快,不亲和花粉管在花柱中生长受抑制程度越弱。2.检测出三个新的S-RNase基因片段,命名为P.a S8(来自凯特)、P.a S9与P.a S10(来自新世纪),已经在GenBank中注册(注册号分别为:AY864826、AY864825、AY884212、AY853594、AY846872);进一步对3个S-RNase基因的DNA和其相应的cDNA序列进行比对,发现在第二、第三保守区之间的高变区中,存在有一段内含子,S8、S9、S10基因的内含子长度分别为406bp、471bp、104bp;结合GenBank中Blast的结果,对蔷薇科李属(Rosaceae Prunus)果树55个S-RNase基因构建系统进化树,显示李属果树S-RNase基因的种内相似性并不高于种间相似性。3.凯特和新世纪中S-基因的mRNA在气球期花柱中都表达;自交亲和与自交不亲和杏的S-RNase基因在授粉前后的发育进程中不仅表达模式不同,而且在决定亲和性的关键时期即授粉后24 h存在表达量的明显差异,新世纪中表达丰度比凯特明显要高;在带柱头的花柱上部、花柱下部及子房各部位中,S-RNase的表达分布不均匀,以花柱上部表达量最丰富;异花授粉后S-RNase基因表达维持在较高水平不继续下调,而自花授粉与不授粉的表达模式无明显差异,均显示持续下降趋势。4.检测没有发现凯特×新世纪F1代杂种的S-RNase基因出现任何形式的碱基突变与序列重组,鉴定出F1代23、37号的S基因型为S9Sc(Sc表示在花柱中缺失的自交亲和基因),29、31号的S基因型为S8S9,杂种35、40号的S基因型为S8S10;按不同的S-基因型分别分析S-基因相对表达量与自交不亲和性的关系,可以看出,只表达一条S-基因的株系,无论S-基因相对表达量高还是低,都表现为自交亲和;表达两条S-基因的株系,更多还原

【Abstract】 Self-compatible (SC) Katy, self-incompatible (SI) Xinshiji and their F1 hybrids were used for probing into molecular and physiological mechanism of difference between self-compatible (SC) and self-incompatible (SI) apricot (Prunus armeniaca). Physiological characterization associated with self-incompatibility was compared between self-compatible (SC) and self-incompatible (SI) apricot. Stylar S-RNases gene in Katy, Xinshiji and their F1 hybrids were isolated, cloned and compared, and expression characteristic of stylar S-RNase in transcript and translation level were identified. The stylar proteins in the SI and SC hybrids were used to compare proteome expression profile. The main results were as followings:(1) After self-pollinated, pollen tubes traveling along the style in Katy could grow into ovary, and most of them in Xinshiji could stop growing with tip expanded into ball. Traveling periods of pollen tube from the stigma to ovary were between 24 h and 72 h and the inhibited degree of self-pollen tube growth in Xinshiji were weakened when traveling speed was quick.(2) Three novelty S-RNase genes (P.a S8 from Katy and P.a S9, P.a S10 from Xinshiji) were found and they have been deposited in GenBank (The accession numbers are AY884212, AY864826, AY864825, AY853594 and AY846872). The introns of P.a S8, P.a S9, and P.a S10 were 406 bp, 471 bp, 104 bp and lied in the hypervariable region (RHV) between C2 and C3. Three genes were compared and displayed similarity at the deduced amino acid level. Most of amino acid sequences of S-RNase gene in Rosaceae Prunus genus were used to form their phyligenetic tree. The evolutionary relationships showed S-RNase genes did not form a distinct cluster within species. Intra-species similarity was not higher than inter-species one.(3) Expression of the S-RNase genes in Katy and Xinshiji were different; Transcript abundance was distinctly diverse at the key stage (i.e., at 24h after self-pollination) in both genotypes, and was greater in Xinshiji than in Katy; In addition, the abundance of the S-RNase transcript was higher in upper-half part of style than in the lower-half part of style or in the ovary; In the SI cultivar Xinshiji, the expression of S-RNase reminded a relatively high level after cross-pollination, but it dropped continuously after self-pollination and non-pollination.(4) Recombination and S-gene mutation had not been found in S-RNase of Katy×更多还原