玉米温敏自交不亲和材料花丝SSH-cDNA文库的构建

为了解玉米温敏自交不亲和材料HE97的表达机制,构建了该材料自交亲和与不亲和阶段花丝的正向与反向抑制差减杂交文库,并对其中的219个正向克隆和52个反向克隆进行了测序分析,分别获得了49个和20个Unique ESTs,涉及到代谢、光合作用、信号转导、物质运输、蛋白质合成加工、防御反应、细胞的发育和衰老、基因表达等重要生命过程中的12种不同功能类型.通过电子克隆获得了包含1090 bp的烯脂酰辅酶A水合酶基因,并对其蛋白质功能进行了分析.     

金珠果梨S基因型的确定

大多数梨属于配子体自交不亲和果树,自然授粉结实率低、品质差。通过确定梨品种S基因型可寻找简便快速克服自交不亲和性的方法。金珠果梨是从野生砂梨中选育出来的新种质。以金珠果梨幼叶为试验材料,对其基因组DNA进行S基因特异扩增、克隆、DNA序列测定及生物信息学分析等,结果表明：金珠果梨S基因型为S₃S₁₉。     

南疆扁桃品种自交不亲和S-Rnase基因型鉴定

[目的]鉴定南疆扁桃品种自交不亲和S-RNase基因型,可为科学合理地配置授粉品种提供依据,有效提高南疆扁桃的产量.[方法]以南疆10个扁桃品种的叶片为试材,利用蔷薇科通用引物PaConsⅡ-F+PaConsⅡ-R、EM - PC2consFD+ EM - PC3consRD对叶片基因组DNA进行S-RNase特异性扩增,将克隆测序结果在GenBank上进行同源性比对.[结果]显示10个扁桃品种均获得2条带,共20条带,包含16种不同的S基因核苷酸序列,其中4个为GenBank上登录的已知S -RNase基因序列,分别为S1(1 370 bp)、S12(2 479bp)、S14(740bp)、S52(1 626bp),12个为新的S-RNase基因序列,暂时分别命名为SA(780bp)、SB(530bp)、SC(1261 bp)、SD(432 bp)、SE(1266bp)、5F(270 bp)、SG(1263 bp)、SH(272 bp)、SI(690 bp)、SJ(1 523bp)、SK(755bp)、SL(1 486bp).[结论]鉴定出10个品种的S- RNase基因型.     

Genetic analysis of rapeseed self-incompatibility lines reveals significant heterosis of different patterns for yield and oil content traits

Self‐incompatibility is one of the most effective approaches to utilizing heterosis in oilseed rape around the world. To evaluate the heterosis of double low self‐incompatibility, the possibility of combining seed yield and oil content, and the genetic effects of parents on their hybrid progenies, a 2‐year field trial using a 3 × 22 NC II mating design was conducted during the 1999‐2001 growing seasons in Wuhan, China. Significant differences in seed yield per plant and seed oil content were observed among the F1 hybrids and between F1 progenies and their parents. However, the heterosis for seed yield per plant was much greater than that for seed oil content. Mid‐parent heterosis and high‐parent heterosis of seed yield per plant ranged from 5.50 to 64.11% and from –2.81 to 46.02%, while those of seed oil content ranged from –1.55 to 7.44% and –3.61 to 6.55%, respectively. Non‐additive genetic effects were a major mechanism that accounted for the yield heterosis in addition to additive effects. In contrast, seed oil content heterosis was mainly dependent on an additive genetic effect. General combining ability (GCA) determined the stability of hybrid cultivars. In hybrid breeding, parental materials might be selected by the sum of GCAs and variances of special combining abilities (SCAs) of female and male parents for traits affected by both additive and non‐additive effects, and by the sum of GCAs of two parents for traits controlled mainly by additive effects. Primary branches and their siliques were the most important yield traits.     

苹果自花授粉花粉管生长和花柱保护酶活性与内源激素含量的关系

以自交亲和的苹果品种早红香和自交不亲和的苹果品种斗南、富士、金冠为试验材料,对授粉后花粉管生长情况,花柱SOD,POD,CAT活性,MDA,蛋白质含量及4种内源激素含量进行研究.结果表明:自交不亲和的品种异花授粉和自交亲和的品种白花授粉后花粉管能够正常生长并通过花柱基部.自交不亲和的品种自花授粉后0-24 h花粉管能正常生长,当花粉管生长到距柱头1/2时停止生长;自交亲和的苹果品种早红香自花授粉后0~48 h花柱SOD,POD,CAT活性相对稳定,自交不亲和品种白花授粉后24～72 h(花粉管已停止生长)3种酶活性及MDA含量变化较大;自交亲和的苹果品种早红香自花授粉后24 h花柱GA_3含量达到峰值而ABA含量下降,而自交不亲和的品种白花授粉后12-48 h花柱ABA含量开始大幅上升,自交亲和品种白花授粉后12-24 h(IAA+GA3)/ABA值急剧上升,之后开始下降,但(IAA+GA_3)/ABA值高于其他自交不亲和品种.     

Breakdown of self-incompatibility in perennial ryegrass at high temperature and its uses in breeding

Summary The maximum temperature (34°C) at which perennial ryegrass plants from one breeding population successfully shed pollen was determined and the seed set of ten clones taken from the same population and self-pollinated both in an unheated glasshouse and at a constant 34°C during anthesis was compared. Seed set by selfing of all ten clones was markedly increased by heat treatment, from a mean of 2.3% to 30.7%. Heat treatment of anthers, but not stigmas, greatly enhanced pollen tube growth on stigmas from the same genotype. Germination of progeny was not affected by the heat treatment. Heat treatment of ten clones from a breeding population with contrasting morphology and growth rate was not so successful. Only one clone shed pollen freely at 34°C and showed a marked improvement in subsequent seed set. The advantages to the breeder of routinely producing full-sib families of elite perennial ryegrass parents by selfing are outlined.     

Estimation of introgression rate of a fescue isozymic marker into tetraploid Italian ryegrass at early generations of backcross

The potential for introgression of Festuca glaucescens into tetraploid ryegrass Lolium multiflorum was assessed using a simplex homeoallele at the phosphoglucoisomerase isoenzyme locus (Pgi-2). Overall, the F. glaucescens species-specific marker was found to be transmitted into Italian ryegrass at a rate close to 0.5 suggesting a high rate of homeologous pairing in BC1 and of intergeneric recombination in BC2. Significant variations in transmission rate among progenies in advanced generations indicated that recombination could result from various chromosome rearrangements possibly involving more than one fescue chromosome with some selection against duplex-like introgressed genotypes. Hence, introgressing F. glaucescens genes into tetraploid ryegrass appeared as further procedure to exploit versatility in fescue species, mostly restricted so far to introgression from F.arundinacea or F. pratensis into diploid ryegrass. Implications in terms of breeding strategy and marker-assisted selection are briefly discussed in respect to the genetic control of traits of interest to be introgressed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Identification of self-incompatibility alleles (S) by PCR-RFLP in radish (Raphanus sativus L.)

From 16 inbred lines of cultivated radishes (Raphanus sativus L.), 6 S-alleles tentatively named S²⁰¹ to S²⁰⁶ were identified, and their dominance relationships were examined. Among the S-alleles, S²⁰¹, S²⁰², S²⁰³ and S²⁰⁴ were found to be co-dominant. These 4 S-alleles showed dominance with S²⁰⁵ in pollen and with S²⁰⁶ in both pollen and stigma, while S²⁰⁵ and S²⁰⁶ were co-dominant. Polymerase chain reaction (PCR) was performed using the radish inbred lines randomly selected from the 6 S-allele groups. The primers were based on the highly conserved sequences of the S-locus specific glycoprotein (SLG) genes in Brassica oleracea. As a result of the PCR, a single DNA fragment of about 1.16kb was amplified as expected from the original sequence of B.oleracea. The S-allele specific pattern in the restriction fragments of the PCR products (PCR-RFLP) was confirmed for the first group of S-alleles (S²⁰¹, S²⁰², S²⁰³ and S²⁰⁴). However, for the second group of the S-alleles (S²⁰⁵ and S²⁰⁶), no PCR products were obtained. The usefulness of the PCR-RFLP in a radish breeding program is described. This revised version was published online in July 2006 with corrections to the Cover Date.     

甜荞结实性及授粉受精过程中花粉管的生长动态

【目的】探究甜荞的结实性及授粉受精过程中花粉管的生长动态,为甜荞自交不亲和性机理的研究奠定基础。【方法】以同型花和异型花甜荞品种为材料,在温室条件下利用自然和人工杂交授粉,调查结实率,并对异型花品种的自交和杂交花柱进行荧光显微观察。【结果】1)同型花品种结实率31.5%~72.7%,其为自花结实性品种;异型花品种的结实率为0~6.3%,其为自花不结实品种。2)异型花的异类型花之间杂交结实,其中以长花柱为母本杂交时的结实率高于以短花柱为母本杂交时的结实率;异型花的同类型花之间杂交时不结实或结实率很低,少量的结实发生在长花柱与长花柱类型杂交之间。3)在异型花品种中,长花柱与长花柱杂交授粉,花粉萌发,花粉管伸长,但在花柱的2/3处(时间为1~1.5h)被抑制,其识别部位尚不清楚;短花柱与短花柱杂交授粉,花粉萌发,但花粉管没有伸长,因此其识别和抑制部位均在柱头;异类型花之间杂交花粉管发育正常,并且花粉发育速度快于同类型花之间杂交。【结论】异型花甜荞自交或同类型花之间杂交,花粉管在柱头或花柱中被抑制使甜荞结实率降低,从而降低产量。同型花品种自交可育,结实率提高,培育同型花甜荞是提高产量的有效手段。     

中国白梨PbSFBB13-gamma基因的分子克隆与序列特征

以5个已知S基因型的中国白梨品种为试材,设计分别对应于梨SFBB-alpha,SFBB-beta和SFBB-gamma 基因的3对引物对这5个品种进行基因组PCR扩增.结果仅引物组合PSFBG-F/PSFBG-R从‘金花'(S_(13)S_(18)),‘金花四号'((S_(13)S_(18))和‘鹅梨'((S_(13)S_(34))中扩增出一约1 300 bp的条带,经回收、克隆、测序后,鉴定其为SFBB-gamma基因,命名为PbSFBB13-gamma(Pyrus bretschneideri SFBB13-gamma),GenBank登录号为EU081892.逆转录PCR结果表明PbSFBB13-gamma仅在花粉中特异表达;序列分析表明该基因不含内含子,编码区含1 191个核苷酸,编码396个氨基酸,预测分子质量与等电点分别为45.4 ku、4.63.PbSFBB13-gamma表现出典型的花粉SFB/SLF基因的基本结构特征,即1个F-box结构域及4个可变区;在推导氨基酸水平上,其与蔷薇科SFB/SLF基因的相似性为17.8%-97.7%.试验结果充分表明PbSFBB13-gamma应为花粉S基因的候选基因.选取蔷薇科34个SFB/SLF基因的全长氨基酸序列,构建进化树研究基因间的进化关系.结果表明,34个SFB/SLF基因形成2个亚科特异的类群,但不形成种特异的类群,其进化规律与蔷薇科S-RNase基因一致,即花粉SFB/SLF基因的形成也是在亚科形成之后、种形成之前.研究结果有助于从分子水平上揭示中国白梨的自交不亲和性机制.