在水稻花培后代中RFLP零等位的遗传分析

在构建水稻分子图谱的研究中,有４ 个ＲＦＬＰ探针揭示了一对籼粳稻之间的零等位现象．其中ＲＧ ２２９ 揭示了籼稻“圭６３０”（Ｏｒｙｚａ ｓａｔｉｖａ ｓｓｐ． ｉｎｄｉｃａ）两个零等位位点;ＲＧ ４１９,ＲＧ４２４ 及ＲＧ ３５３ 揭示了粳稻“０２４２８”（Ｏ． ｓａｔｉｖａ ｓｓｐ．ｊａｐｏｎｉｃａ）的零等位． 利用８１ 个圭６３０／０２４２８ 的花培植株（ＤＨ）进行的遗传分析结果表明,这些零等位位点与ＭｃＣｏｕｃｈ 发表的水稻分子图谱中其相邻分子标记间的连锁关系发生了变化．另外,用ＲＧ ６８４ 探针在一些ＤＨ植株中检测出有新的零等位出现,虽然双亲都具有与ＲＧ ６８４ 同源的序列． 零等位的出现可能与转座因子的转位有关     

利用分子标记定位水稻野败型核质互作雄性不育恢复基因

以籼稻恢复系圭６３０与粳型广亲和品种０２４２８的Ｆ１代花药培养,获得８１个双单倍体（ＤＨ）,构建了有２３３个ＲＦＬＰ标记的分子图谱。用籼稻野败型不育系珍汕９７Ａ测定各ＤＨ系的恢复性,并将恢复性作为数量性状进行ＱＴＬ的区间作图分析,鉴别出８个基因座位,其中有２个基因座位,Ｒｆｉ－３和尾Ｒｆｉ－４,单个ＱＴＬ的基因贡献值分别是４９．６％和３５．４％,对育性恢复起主要作用,定为主效基因座位,位于第三和四染色体上,其它６个基因座位对育性恢复亦有一定的影响。表明野败型雄性不育恢复性是受主效基因和微效基因共同控制的性状。     

云南地方稻种的遗传变异和籼粳分化

用７ 个单拷贝探针对８７ 份云南稻地方品种进行了ＲＦＬＰ分析．结果表明∶云南稻（Ｏｒｙｚａｓａｔｉｖａ Ｌ．）地方品种中,籼稻（ｉｎｄｉｃａ）和粳稻（ｊａｐｏｎｉｃａ）都表现出较高水平的变异,粳稻的等位基因数目和遗传多样性水平都高于籼稻,表明粳稻的遗传变异比籼稻丰富． 云南稻地方品种中的籼稻和粳稻间表现出明显的遗传分化,且不同染色体区段分化程度不同． 研究结果支持栽培稻的二系起源学说     

海岛棉原位杂交及核型比较

采用Ａ染色体组（Ａ genome)棉种亚洲基因组ＤＮＡ（gDNA)为探针,对海岛棉体细胞染色体进行荧光原位杂交（ＦＩＳＨ）,结果发现５２条染色体中有杂交信号与否的刚好各一半,从而直观地证实了海岛棉异源双二倍体起源的理论,但是,染色体的长度Ａ亚组的并非全部大于Ｄ亚组的。海岛棉基于ＦＩＳＨ图像的核型公式为：２n=4x=52=38m 14sm(sat)。３对随体染色体序号分别是Ａ亚组第１１、Ｄ亚组第２２和２５,均属于近中部着丝点（sm)类型,随体均在各自杂色体的短臂上,而且与所有染色体无关晨同一亚组起源。Ａ亚组第５、６和９对染色体长臂发生长了片段的易位,易位的片段较大,占所在染色体和蔗的百分率依次为１９．２１％、１７．６９％和１２．８８％,在Ｄ亚组１３对染色体中,最少５对的着丝点区域多或少地显示出与亚洲棉gDNA探针杂交的红色荧光信号,意味着有Ａ亚组染色体的交换。     

Ds因子在烟草染色体插入位点旁邻顺序的克隆

用ＮｅｓｔｅｄＰＣＲ 方法从含Ｄｓ 因子的转基因烟草ＤＮＡ 中克隆了Ｄｓ 因子在烟草染色体插入位点的９ 个旁邻ＤＮＡ 片段,以这些片段作探针,和野生型烟草的ＤＮＡ 进行Ｓｏｕｔｈｅｒｎ 杂交,以检测这些片段在烟草基因组中的拷贝数,结果表明它们都属于烟草染色体上的低拷贝ＤＮＡ。另外,对这些ＤＮＡ 片段进行核苷酸序列测定,并将它们的顺序与Ｇｅｎｂａｎｋ 数据库中已有的核苷酸序列相比较,其中长度为１２８ 核苷酸的片段１ 和荷兰芹的４ＣＬ２ 基因的一个区段有５７ ．８ ％ 同源性,而另一长度为１６９ 核苷酸的片段３ 和百合中的反转座子的一个区段有６０ ．９ ％ 的同源性。这都表明Ｄｓ 因子在异源植物烟草中插入染色体单拷贝基因的机率很高,这对转座子标签法克隆基因是非常有利的。     

籼粳不育新位点的发现及其遗传分析

粳稻０２４２８携有Ｓ－５ｎ广亲和基因,然而与籼稻ＩＲ２４杂交表现为半不育。对０２４２８与ＩＲ２４．Ｐｅｃｏｓ、秋光等品种杂交的分离世代的小穗育性进行遗传分析,结果表明：０２４２８与ＩＲ２４之间的不育性受单基因控制,遗传规律符合单位点孢子体一配子体遗传模式,不育性由非Ｓ－５的新位点引起,美国品种Ｐｅｃｏｓ具有复等位的中性基因;ＲＦＬＰ标记技术检测后初步确定,该新不育位点在第１１染色体上的标记Ｇ２４附件,与目前已报道的不育位点都不等位,新位点暂定名为Ｓ－ｐ（ｔ）。研究结果还显示,粳稻品种秋光与籼稻品种ＩＲ２４之间的不育性受２个不育位点Ｓ－５和Ｓ－ｐ（ｔ）控制,其遗传效应表现有累加作用。     

由小麦×玉米获得的普通小麦加倍单倍体后代的RFLP变异

用小麦（Ｔｒｉｔｉｃｕｍ　ａｅｓｔｉｖｕｍＬ．）的ｒＤＮＡ克隆ｐＴａ７１和与小麦基因组有部分同源性的玉米（ＺｅａｍａｙｓＬ．）ＤＮＡ克隆作探针,对由小麦ｘ玉米获得的普通小麦加倍单倍体（ＤＨ）后代群体进行ＲＦＬＰ分析。结果发现,不但用ｐＴａ７１在这些ＤＨ后代中检测到ｒＤＮＡ所发生的明显的减少和扩增及非转录间隔区的限制性片段长度的变化,而且用与小麦基因组部分同源的玉米克隆ＭＲ１３和ＭＲ５０在一些ＤＨ后代中检测到缺失变异,特别是用ＭＲ１３在普通小麦ＤＨ系的１８号株的基因组中检测到大幅度的限制性片段长度的变化,即原来的４．３ｋｂ的强信号带消失,取而代之的是４０．０ｋｂ、２．５ｋｂ和２．０ｋｂ三条杂交带。这可能与小麦基因组ＤＮＡ较大的重排事件有关,也可能是由外源的玉米ＤＮＡ插入造成的。     

Ds因子在烟草染色体插入位点旁邻顺序的克隆

用Ｎｅｓｔｅｄ－ＰＣＲ方法从含Ｄｓ因子的转基因烟草ＤＮＡ中克隆了Ｄｓ因子在烟草染色体插入位点的９个旁邻ＤＮＡ片段,以这些片段作探针,和野生型烟草的ＤＮＡ进行Ｓｏｕｔｈｅｒｎ杂交,以检测这些片段在烟草染色体上的低拷贝ＤＮＡ。另外,对这些ＤＮＡ片段进行核苷酸序列测定,并将它们的顺序与Ｇｅｎｂａｎｋ数据中已有的核苷酸序列相比较,其中长度为１２８核苷酸的片段１和荷兰芹的４ＣＬ－２基因的一个区段有５７．８％     

用分子原位杂交（GISH）鉴定小麦－簇毛麦双倍体、附加系、代换系和易位系

用生物素标记的簇毛麦（Ｈａｙｎａｌｄｉａｖｉｌｌｏｓａ）染色体组ＤＮＡ（ｔｏｔａｌｇｅｎｏｍｉｃＤＮＡ）作探针,以普通小麦染色体组ＤＮＡ作遮盖（用量１：２００左右）,进行有丝分裂中期和减数分裂中期Ｉ染色体的分子原位杂交（ＧＩＳＨ）,经抗生物素蛋白－辣根过氧化物酶复合物（ｂｉｏ－ｓｔｒｅｐｔａｖｉｄｉｎ－ｈｏｒｓｅｒａｄｉｓｈｐｅｒｏｘｉｄａｓｅ）和联苯胺四盐酸（ＤＡＢ）检测显色后,小麦－簇毛麦双倍体、附加系、代换系和易位系中的簇毛麦染色体及染色体片段显棕色,与显浅蓝色的小麦染色体可明显区分。用ＧＩＳＨ不仅可以检测导入小麦中的簇毛麦染色质,而且可以清楚地显示出易位染色体断裂点的确切位置。将ＧＩＳＨ用于减数分裂期染色体配对分析,还可以清晰形象地显示出同源和非同源染色体之间的配对和分离情况。     

水稻亚铁胁迫诱导ADH的基因定位及其遗传分析

籼稻品种ＩＲ６４与粳稻品种Ａｚｕｃｅｎａ及其ＤＨ群体１３５个系用于进行Ｆｅ＾２＋胁迫（２５０ｍｇ／Ｌ,ｐＨ４．５）及对照实验,对处理及对照条件下的ＡＤＨ进行基因定位及遗传分析,结果表明,在Ｆｅ＾２＋胁迫条件下,ＡＤＨ酶的活性大大提高,群体在Ｆｅ＾２＋胁迫条件下,表现低值的超亲现象,分布偏向ＩＲ６４,单标记分析和最大似然区间作图结果表明,Ｆｅ＾２＋胁迫条件下,１１号染色体上紧密连锁的３个标记位点ＲＧ     

Genetic Mapping of Rice Using RFLP Markers and a Double Haploid Population of a Cross Between indica and japonica Varieties

A genetic linkage map of rice was constructed using a double haploid (DH) population from "Gui 630” (Oryza sativa subsp, indica)/"02428" (O. sativa subsp, japonica, wide compatibility variety) and RFLP markers. It consists of 233 loci and covers rice genomes about 2070 cM (centimorgan), and compares well with the other published rice maps. 25 RFLP markers, 2 telomeres and sh-2 (shattering ability) gene were first located on the molecular map of rice. RFLPs between "Gui 630' and "02428' mainly came from base substitution and a few DNA construction variance, not distributed evenly among chromosomes and on chromosome. This was probably resulted from the difference genetic stability among chromosomes and regions, in exchanging recombination ability in different segments of chromosome.     

Genetic Analysis of Null Alleles in Rice Doubled Haploid Plants from Anther Culture

In the research of constructing a rice(Oryza sativa) molecular map, 4 RFLP markers, i.e. RG 229, RG 419, RG 424 and RG 353, detected the null alleles in the indica and japonica parental rice. RG 229 indicated two null alleles in indica rice Gui 630, and each of the other markers revealed a null allele in japonica rice 02428. Genetic analysis in the doubled haploid (DH) population consisting of 81 plants showed that the linkage relationships between these null allele loci and the neighboring molecular markers shown in McCouch' s rice molecular map were changed. In addition, the marker RG 684 could detect its null alleles in some DH plants, though the RG 684 sequence did exist in the genomes of both parents. Appearence of null alleles might be induced by transpositional changes on chromosomes.     

Genotypic Mapping Using RFLP Markers on Doubled Haploids Derived from a Cross Between indica and japonica Rice

A rice RFLP map with 233 loci based on a population of 81 doubled haploids (DH) from the indica/japonica hybrid of "Gui 630'/"02428" was used to analyse the genome ratios and graphical genotypes of DH lines. The “Gui 630” genome ratio of the individual DH lines varied from 29.3% to 78.6% with an average of 49% while the ratios of most DH lines ranged between 44% and 49%. Of the mapped RFLP markers 130 showed skewed segregations with a significant deviation from the expected monogenic ratio, but the numbers of the markers deviated towards male and female parent were approximately equal. It was found that the markers with the segregation deviation in the same direction tend to cluster on some chromosomes and some of their regions. The average "Gui 630' genome ratios of different chromosomes in the DH population varied greatly between 29% and 65 %. In addition, several chromosomes were inherited completely from either one of the parents in some DH lines, indicating the rare occurrence of crossover along the pairing homologous chromosomes during meiosis.     

利用RFLP标记分析一对水稻籼粳交双单倍体的基因型

对一对籼(Oryza sativa ssp.indica)粳(O.sativa ssp.japonica)(“圭630”/“02428”)杂种进行花药培养获得81个双单倍体(DH),构建了有233个RFLP标记的水稻遗传连锁图谱。对各DH系的“圭630”等位基因组频率及图示基因型进行了分析。结果表明,该DH群体的平均基因组频率为49％,各DH系分布在29.3％～78.6％之间,集中分布在44％～49％之间;有130个RFLP标记出现显著的偏分离,偏父本与偏母本分离的标记数基本相等;同向偏分离的标记常集中在一些染色体或染色体的某些区段;各染色体的平均基因组频率分布在29％～65％之间,出现明显的偏父或偏母分离;一些DH中出现其特征完全来于某一亲本的染色体,可能与这些染色体在减数分裂期的同源配对和交换有关。     

RFLP Analysis of Progeny from Hybrid of Oryza alta×O.sativa

Oryza alta Swallen is a species of allotetraploid wild rice (CCDD, 2n = 48) with high biomass production and resistant to several insects and diseases. The high polymorphism (RFLP) between O. alta and O. sativa L. (average 90%) reveals the long phylogenical distance between these two species which may impede the crossing. The chromosome constitutions of several progeny from O. alta × O. sativa were analyzed with 22 mapped rice RFLP markers. The results showed that almost all triploid sterile plants which had 36 chromosomes were, as expected, composed of the chromosomes from two parents. But the two partial fertile regenerated plants from 02428 (O. sativa) × WHS601-2 (O. alta) which had only 24 and 25 chromosomes respectively, in most cases, had RFLP patterns similiar to their O. sativa parent. Therefore the chromosomes constituted their genomes were mainly from O. sativa or have high homology with the chromosomes of O. sativa. It seems evident that chromosome elimination had occurred during the wide hybridization as O. alta RFLP patterns could be found in them. Furthermore, that the introgression of O. alta chromosome fragment into that of O. sativa in an F2 plant was indicative that some kind of recombination also occurred. Regarding the rare chromosome pairing in PMCs, the probability of the existence of a nonconventional mechanism for the wild rice chromosomes (chromosome fragments ) to introgressing into cultivated rice genomes in a relatively short time was discussed.     

RFLP mapping of major and minor genes for important agronomic characters in rice

A molecular genetic map with 233 RFLP markers which covered about 2070 cM of rice genome was constructed based on a doubled haploid (DH) population derived from anther culture of a cross between an indica variety Gui630 and a japonica variety 02428. Quantitative trait loci (QTLs) for agronomic characters such as number of panides, heading date, plant height, number of spikelets, number of grains, fertility and 1 000-grain weight were analyzed using interval mapping approach. 8 major genes and 29 minor genes were identified associating with these traits. The results also indicated that great phenotypic difference between parents was profitable in detection of major genes.     

Segmental Duplications Are Common in Rice Genome

Segmental duplications on rice (Oryza sativa L.) chromosomes 8, 9, 11, and 12 were studied by examining the distributions of sequences resolved by 13 probes detecting multiple copies of DNA sequences. Four of the hybridization bands detected by a repetitive sequence probe, rTRS, were mapped to the ends of all the four chromosomes. Two or three of the bands detected by each of the other 12 probes were also mapped to different chromosomes. The bands detected by the same probe usually occurred in similar locations of different chromosomes. Loci detected by different DNA probes were often similarly arranged on different chromosomes. Chromosomes 8 and 9 showed colinearity of marker loci arrangement indicating a possible common origin. A segment on chromosome 9 was also very similar to the previously reported duplicated fragments on the ends of chromosomes 11 and 12 which were also detected in this study, indicating a likely common origin. Moreover, the various degrees of distributional similarity of the segments suggest a complex relationship among the chromosomes in the evolution of the rice genome. These results support the proposition that chromosome duplication and diversification may be a mechanism for the origin and evolution of the chromosomes in the rice genome.     

Genetic analysis and gene mapping of a rice few-tillering mutant in early backcross populations (Oryza sativa L.)

A rice mutant, G069, characteristic of few tiller numbers, was found in anther culture progeny from the F1 hybrid between an indica-japonica cross, Gui630×02428. The mutant has another two major features: delayed tillering development and yellowing apex and margin on the mature leaves. As a donor parent, G069 was further backcrossed with the recurrent parent, 02428, for two turns to develop a BC2F2 population. Genetic analysis in the BC2F2 population showed that the traits of few-tillering and yellowing apex and margin on the mature leaves were controlled by one recessive gene. A pool of equally mixed genomic DNA, from few-tillering individual plants in BC2F2, was constructed to screen polymorphism with simple sequence repeat (SSR) markers in comparison with the 02428 genome. One SSR marker and three restriction fragment length polymorphism (RFLP) markers were found possibly linked with the recessive gene. By using these markers, the gene of few-tillering was mapped on chromosome 2 between RFLP marker C