谷子雄性不育系1066A不育基因和黄苗基因的染色体定位

以谷子（Setaria italica(L).Beauv.)雄性不育系1066A为母本,豫谷1号三体（1-7）及四体8和四体9作父本进行杂交,应用初极三体分析法,进行了谷子雄性不育基因和黄苗基因的染色体定位研究。通过配置大时杂交组合和反复授粉,利用豫谷1号三体的极少量花粉,获得了三体2-9的F1代杂种,各杂种三体的形态与豫谷1号三体基本个似,略有差异,苗色呈绿色且可育。杂种F2植株的育性都产生分离。结果是三体3、5、7、8、9的F2代分离出的可育株与不育标之比为3：1,三体6的可育株与不育株之比为14：1（x^2=0.012,p=0.01)。杂种F2分离出的绿苗与黄苗之比只有三体7为12：1（X^2=0.36,P=0.01),其他均为3:１。因此,可以确定1066A的不育基因为隐性单基因,位于第6号染色体上,该品系的黄苗基因也是隐性单基因,位于第7号染色体上。     

谷子显性雄性核不育基因的发现与利用

植物界的雄性不育现象绝大部分都是由隐 性雄性不育基因控制的。1978年我们在澳大利 亚谷和吐鲁番谷的杂交后代中发现一份雄性不 育材料。从1978-1984年7个世代的遗传表 现为：和400个谷子普通品种杂交,其不育株 自由授粉、其不育株和分离出来的可育株杂交、 和原父回交,F,就出现育性分离,不育与可育的 比率都为1：1;其可育株后代育性不分离;其不 育株自交子一代育性分离,不育与可育的比率 为3:1。如此证明,这份雄性不育材料的不育 性是受显性雄性不育基因控制的。     

大白菜细胞核复等位雄性不育基因定位

以大白菜不育材料"939A"为母本,携带恢复基因的材料YDQ56A为父本构建隐性雄性不育F1S4分离群体,利用混合分组分析法(BSA)对不育基因初定位;同时以"939A"为母本,携带保持基因的材料yellow sason为父本构建显性雄性不育F2分离群体,对不育基因进行精细定位。结果在F1S4群体中获得与不育基因连锁的标记2个,A08_1900和Br ID111035,与不育基因分别相距8.8c M和2.5c M,物理距离为804.1kb;F2群体中不育单株与可育单株分离比符合3∶1,不育基因表现为显性。通过标记验证,F2和F1S4两个群体定位结果一致,均位于A08染色体末端,通过新标记的筛选获得不育基因两侧紧密连锁的标记Br19470306和Br19675586,与不育基因分别相距1.6c M和2.4c M,物理距离205.28kb,其中包含58个基因。该结果为大白菜雄性不育系的利用以及转育奠定了基础。     

太古核不育小麦显性不育基因的染色体组测定

以太谷核不育小麦为母本与5个四倍体小麦种——硬粒小麦、波斯小麦、波兰小麦、埃及小麦、东方小麦为父本,进行杂交和回交。杂种F_1育性分离比例是:不育株与可育株为1:1,染色体构型为14Ⅱ+7Ⅰ。不育株的回交后代是随着回交次数的增加,分离出的不育株数逐次减少,可育株数逐次增多,极显著偏离1:1;BC_3不育株绝大多数染色体构型为14 Ⅱ+1 Ⅰ,带有一个单价体,BC_3可育株染色体构型为14Ⅱ。杂种F_1的可育株,其回交后代全是可育株,没有分离出1株不育株。以太谷核不育小麦为母本与3个六倍体小麦种—印度矮生小麦、瓦维洛夫小麦、密穗小麦为父本,进行杂交和回交,其后代育性分离比始终为1:1。测定结果表明:太谷核不育小麦的显性不育基因是在D组染色体的某个染色体上。因而这个基因不能直接导入不含有D组染色体的小麦种中去,如硬粒小麦。     

小麦Ms2基因易位后的染色体组定位研究

Ms2基因易位后育成的显性核不育六倍体小黑麦与硬粒小麦（包括二粒小麦）杂交,F₁代群休中的不育株用原父本连续回交,每轮F₁群体中的不育株与可育株之比都符合1:1。同时用黑麦为父本所做的杂交与回交,各F,群体中的不育株比例明显下降。说明易位后的Ms2基因到达A或B染色体组的某一条染色体上了。细胞学检查的结果也支持这一结论。     

合成甘蓝型油菜中双隐性雄性核不育材料的发现及遗传规律分析

从甘蓝型油菜与白菜型油菜的种间杂交获得的甘蓝型油菜(Brassica napus)中发现了雄性不育单株,兄妹交株系和不育株与甘蓝型油菜常规杂交F1和F2株系的育性分离分析表明,该不育材料属于双隐性雄性核不育类型.利用育性分离株系的可育株自交和可育株与不育株间兄妹交等方法筛选出7个纯合可育株系,等位测验表明这7个纯合可育株系(B1～B7)中存在两种基因型:Ms1Ms1ms2ms2和ms1ms1Ms2MS2.该材料对油菜核不育基因定位和杂种优势利用研究有重要意义.     

谷子Si-SP1小穗突变基因的遗传分析和定位

通过EMS(Ethyl methylsulfonate,甲基磺酸乙酯)诱变豫谷1号获得一个遗传稳定的谷子小穗突变体si-sp1,该突变体突出表现为穗部变小,同时伴随有株高降低、单码小花数减少和根系变小等表现型变异。与野生型豫谷1号相比,突变体的穗长和株高分别降低了37.8%和9.0%,单穗粒重和单码小花数分别降低了40.3%和31.7%,但千粒重增加了20.2%。遗传分析表明,si-sp1突变性状由1对隐性基因控制。以si-sp1为母本、辽谷1号为父本构建的F2定位群体的隐性单株,将突变基因定位在8号染色体上CAAS8003与SSR1038间约11.02 M的距离内,为下一步精细定位并分离该基因奠定了基础。     

小伞山羊草(Aegilops umbellata)恢复基因向小麦的转移

鉴定了小伞山羊草(Ae.umbellulata)6条染色体的中国春添加系对T型细胞质雄性不育系育性的影响,发现UAD能较好地恢复T型不育系的育性,表明染色体A上携带有育性恢复基因。添加染色体A在提莫菲维细胞质背景中通过雄配子的传递率为15.6%。同时进一步证明中国春不含有恢复基因。 在体细胞染色体数为42的331个不育系与UAD的杂种衍生后代中选到18个可育株,并对部分植株进行了细胞学鉴定。其中040-5、061-1和061-4与中国春的杂种F_1的育性分离和染色体配对情况表明它们是含有来自小伞山羊草染色体A上的恢复基因的杂合易位系。     

玉米隐性核不育突变体ms14的遗传分析与基因定位

玉米雄性不育材料是一种宝贵的种质资源,不育基因的遗传分析与定位研究对玉米分子育种和杂种优势利用具有重要价值。通过对从美国引进的玉米雄性不育突变体材料ms14进行雄花育性鉴定和花药I₂-KI染色,表明该突变体是无花粉型雄性不育;通过不育突变体ms14与正常自交系郑58、昌7-2杂交获得F₁,然后自交构建两个F₂遗传分离群体（ms14×郑58和ms14×昌7-2）,并进行雄花育性调查、数据统计和遗传分析,发现可育株数与不育株数的分离比是3∶1,表明该突变体由隐性单基因控制;通过SSR等分子标记与不育位点的连锁分析,将ms14基因定位在玉米第1染色体的SSR标记umc2025和umc1676之间,遗传距离分别是2.2cM和0.3cM。对玉米不育基因ms14的遗传分析和初步定位,为该基因的精细定位和克隆、不育机理的解析及其产业化应用奠定了基础。     

辣椒细胞核雄性不育材料GMS702AB的鉴定

本研究发现1个具有雄性不育与单性结实特征的细胞核雄性不育系辣椒材料,并对该材料的农艺性状、单性结实坐果率、不同发育时期的不育系单性结实与可育系单性结实内源激素进行测定;利用田间鉴定和显微镜镜检,分析了F2群体的遗传分离情况,并利用辣椒细胞核雄性不育基因ms-3、msw、ms、msms、msc-1开发的分子标记,分析了群体的育性分离比。结果表明：不育系单性结实果实纵横径较大,可育系与不育系单性结实坐果率明显不同,可育系坐果率为22%,不育系坐果率为43%;不同时期不育系单性结实果实的赤霉素（GA4）含量显著高于可育系单性结实果实;田间鉴定和分子标记检测表明,F2群体中可育系有97株,不育系有30株,分离比为3.23∶1,符合孟德尔遗传规律,确定其育性由隐性单基因控制,将该辣椒细胞核雄性不育系命名为GMS702AB。本研究提供新的辣椒不育系,有助于辣椒育种和种子生产。     

Determination of n+1 Gamete Transmission Rate of Trisomics and Location of Gene Controlling 2n Gamete Formation in Chinese Cabbage (Brassica rapa)

A set of trisomics of Chinese cabbage was used for determining the n+1 gamete transmission rate and locating the gene controlling 2n gamete formation on the corresponding chromosome. The results showed that the transmission rates of extra chromosomes in different trisomica varied from 0% to 15.38% by male gametes and from 0% to 17.39% by female gametes. Of the nine F2 populations derived from the hybridizations between each triaomic and Bp058 (2n gamete material), only Tri-4×Bp058 showed that the segregation ratio of plants without 2n gamete formation to plants with 2n gamete formation was 10.38:1, which fitted the expected segregation ratio of the trisomics (AAa) based on the 7.37% of n+1 gamete transmission through female and 5.88% through male. In other populations the segregation ratios varied from 2.48:1 to 3.72:1, which fitted the expected 3:1 segregation ratio of the bisomice (Aa). These results suggested that the gene controlling 2n gamete formation in Chinese cabbage Bp058 was located on chromosome 4. Further trisomic analysis based on the chromosome segregation and the incomplete stochastic chromatid segregation indicated that the gene locus was tightly linked to the centromere.     

TRISOMIC TRANSMISSION IN CLARKIA UNGUICULATA

Vasek , F. C. (U. California, Riverside.) Trisomic transmission in Clarkia unguiculata. Amer. Jour. Bot. 48(9): 829–833. 1961.—Seven primary trisomic plants derived from a triploid-diploid cross were self-pollinated. The 7 progenies included diploids and trisomics, the latter varying in frequency from 16 to 30%. In addition, 2 of the progenies included tetrasomic plants. Crosses were made between diploids and either trisomics or tetrasomics. The extra chromosome of 1 progeny was readily transmitted through the pollen of trisomic and tetrasomic plants. When a trisomic of the same progeny was used as a seed parent, only diploids and tetrasomics were found among the offspring, indicating a duplication of the extra chromosome. The extra chromosomes of other progenies were not transmitted through either pollen or eggs in controlled diploid-trisomic crosses but trisomics of these progenies were recovered after self-pollination. It is suggested that differential pollen-tube growth precluded transmission to diploid-trisomic hybrids and that under conditions of reduced pollen competition the extra chromosome normally would be transmitted through pollen. The extra chromosomes generally occur as univalents at metaphase and are ordinarily included in telophase nuclei.     

Association of the yellow leaf (y10) mutant to soybean chromosome 3

At least 19 single recessive gene yellow leaf mutants and one duplicate recessive gene mutant have been described in soybean. This study was conducted to associate a yellow leaf mutant, y10, with a specific soybean chromosome by using primary trisomics (2n = 41). Seven soybean primary trisomics were hybridized as female parent with genetic stock strain, T161, carrying y10. F(1) disomic and primary trisomic plants were identified cytologically. One disomic (control) and all primary trisomic plants were allowed to self-pollinate and F(2) populations were classified for green versus yellow leaf mutant. The F(2) population of Triplo 3 segregated in a 17:1 ratio, while a disomic (3:1) ratio was observed with Triplo 8-, 17-, 18-, and 20-derived F(2) populations, suggesting that the y10 locus is on chromosome 3. The y10 locus was examined with four simple sequence repeat (SSR) markers (Satt584, Sat_033, Satt387, and Satt022) from molecular linkage group (MLG) N and y10 was found linked with Satt022. Therefore we confirmed the association of MLG N with chromosome 3. The possible association of y10 with Triplo 16 and Triplo 19 are discussed.     

四倍体水稻花药培养筛选初级三体的研究

以同源四倍体水稻 ( Oryza sativa L.)各世代杂种和四倍体籼、粳原种为材料进行花药培养 ,诱导花粉植株再生。根据三体植株表型上相互区别的特性 ,且又显著区别于二倍体 ,对其中所诱导的 1 5个花药培养品系 4 390株 H1花粉植株进行了重点固定和染色体镜检。结果表明 ,花粉 H1植株染色体组成包括二倍体、四倍体和非整倍体 ,其频率分别为 88.0 %、5 .5 3%和 6.67%。鉴定出 2 72株三体 ,占全部花粉植株的 6.2 0 %。对照已配套三体系的形态 ,将鉴定的三体株划分为 9种类型 ,并对其中的 91 2 4 - 7窄叶三体进行粗线期核型分析 ,鉴定为三体 8。将三体 8的种子播种 ,在 H2 代苗期统计额外染色体的传递率 ,三体株占 34 .1 1 % ,其农艺性状也同于 H1亲代     

Genetic and cytogenetic analyses of the A genome of Triticum monococcum. IX. Cytological behaviour, phenotypic characteristics, breeding behaviour, and fertility of primary, double, and triple trisomics.

Cytogenetic studies in Triticum monococcum (2n = 2x = 14, AA) were initiated by generating a series of primary as well as double and triple trisomics from autotriploids derived from crosses between induced autotetraploids and a diploid progenitor. Analysis of meiotic chromosome behaviour revealed that, with the exception of primary trisomics for chromosome 7A, the chromosome present in triple dose in all other trisomics formed either a bivalent plus a univalent or a trivalent (always V shaped) at diakinesis - metaphase I in approximately equal proportions. Trisomics for chromosome 7A formed a bivalent plus a univalent or a trivalent in approximately a 1:2 ratio. About 99% of the anaphase I segregations in all the trisomics were seven to one pole and eight to the other, suggesting that primary trisomics in T. monococcum form n and n + 1 meiotic products in equal proportions. The double trisomics and triple trisomics formed 5 II + 2 III and 4 II + 3 III during metaphase I, respectively. A majority of the secondary meiocytes from the double and triple trisomics possessed unbalanced chromosome numbers. All the trisomics differed phenotypically from their diploid progenitors. Single primary trisomics for chromosomes 3A and 7A produced distinct morphological features on the basis of which they could be distinguished. The phenotypes of the double and triple trisomics deviated to a greater extent from that of diploids than those of the single trisomics. Less than 50% of the progeny of all primary trisomics were trisomics themselves. Trisomic progeny were not produced in diploid female x trisomic male crosses, indicating that functional n + 1 male gametes were not generated. Diploid as well as trisomic progeny were produced in the reciprocal crosses and upon self-fertilization of the trisomics. The average frequency of trisomic progeny was 9.9%. The fertility of primary trisomics ranged from 3.8% in trisomics for chromosome 1A to 40.6% in trisomics for chromosome 2A and was significantly less than that of diploids (99.6%). The breeding behaviour and low fertility of these trisomics make their maintenance and use in cytogenetic analyses difficult.     

Aneuhaploids and tetrasomics in rice (Oryza sativa L.) derived from anther culture of trisomics.

Eight types of aneuhaploids (Aneuhaplo 4, 5, 6, 8, 9, 10, 11, and 12) and eight types of tetrasomics (Tetraplo 4, 5, 6, 7, 8, 9, 10, and 12) of rice have been obtained from anther culture of trisomics. This paper reports the plant morphology of these aneuploids and their chromosome behavior at metaphase I. Aneuhaploids for different chromosomes are distinguishable from each other and are morphologically similar to the parental trisomics, suggesting that the extra chromosome has similar genetic effects on plant morphology at the haploid level as at the diploid level. Similarly, tetrasomics with different extra chromosomes are distinguishable from each other and are similar morphologically to the parental trisomic. However, stronger changes in morphological characters were observed in tetrasomics compared with trisomics having the same extra chromosome, as a result of a dosage effect of the extra chromosomes. Comparing plant size between aneuhaploid, tetrasomic, and trisomic with the same extra chromosome, it was shown that the trisomic was the largest, the tetrasomic was of medium size, and the aneuhaploid was the smallest, except for those plants with an extra chromosome 8 in which plant size is dramatically decreased in both the aneuhaploid and the tetrasomic. At metaphase I, aneuhaploids showed chromosome configurations of 1 II + 11 I and 13 I. The frequency of the 1 II + 11 I configuration is higher than 70%, indicating that homologous chromosomes in aneuhaploids tend to stay associated in meiosis. Intragenome chromosome pairing (2 II + 9 I), so called secondary association, was observed in the aneuhaploid for chromosome 5. Tetrasomic plants showed 5 kinds of chromosome configurations: 1 IV + 11 II, 1 III + 11 II + 1 I, 13 II, 12 II + 2 I, and 11 II + 4 I. A chromosome configuration of 13 II was often observed in tetrasomics with shorter extra chromosomes and a chromosome configuration of 1 IV + 11 II was often observed in tetrasomics with longer extra chromosomes. Aneuhaploids had complete seed sterility. Tetrasomics showed very poor pollen fertility and complete seed sterility, except for a few shriveled seeds that were observed in Tetraplo 6 and 9. This is the first report in rice where many aneuhaploids and tetrasomics have been characterized. This information will help to further unravel rice aneuploidy and cytogenetics. The aneuploids obtained here will be very useful tools for the study of genetics and breeding in rice.     

Secondary Trisomics and Telotrisomics of Rice: Origin, Characterization, and Use in Determining the Orientation of Chromosome Map

Secondary trisomics and telotrisomics representing the 12 chromosomes of rice were isolated from the progenies of primary trisomics. A large population of each primary trisomic was grown. Plants showing variation in gross morphology compared to the primary trisomics and disomic sibs were selected and analyzed cytologically at diakinesis and pachytene. Secondary trisomics for both arms of chromosomes 1, 2, 6, 7 and 11 and for one arm of chromosomes 4, 5, 8, 9 and 12 were identified. Telotrisomics for short arm of chromosomes 1, 8, 9 and 10 and for long arms of chromosomes 2, 3 and 5 were isolated. These secondary and telotrisomics were characterized morphologically and for breeding behavior. Secondary trisomics 2n + 1S.1S, 2n + 1L.1L, 2n + 2S.2S, 2n + 2L.2L, 2n + 6S.6S, 2n + 6L.6L and 2n + 7L.7L are highly sterile, and 2n + 1L.1L, 2n + 2L.2L and 2n + 7L.7L do not set any seed even upon backcrossing. Telotrisomics are fertile and vigorous. Genetic segregation of 43 marker genes was studied in the F(2) or backcross progenies. On the basis of segregation data, these genes were delimited to specific chromosome arms. Correct orientation of 10 linkage groups was determined and centromere positions on nine linkage groups were approximated. A revised linkage map of rice is presented.     

Studies on trisomics in a Jute hybrid

Fifteen red pigmented trisomics were isolated in the F₂ generation from the cross Corchorus olitorius L. x C. capsularis L. In the F₃ generation a few green trisomics were obtained; more of these were isolated from the backcross generation. A detailed morphological and cytological analysis of the trisomic hybrid populations derived from the F₃ and F₄ generations is presented. The trisomics were scored for several morphologically differentiating characters and most of them were intermediate between the parental species, a few resembling the olitorius parent more. Cytological studies showed the formation of abnormal sporads in trisomics with different frequencies indicating a misdivision at meiosis. This imbalance at meiosis results in a higher percentage of pollen sterility in the trisomics as compared with the parents. Analysis of M₁ of meiosis showed that there were: differences in the frequencies of the various chromosome configurations between the two categories of trisomics; significantly higher trivalent frequencies per PMC in the green trisomics; in contrast significantly hihger univalent frequencies per PMC in the red trisomics. No significant difference in chiasma formation was observed between red and green trisomics, nor between trisomics and their parental species. It appears that segmental homology in the parental chromosomes has probably resulted in varying degrees of preferential pairing in the trisomic hybrid.     

PHENOTYPIC VARIATION IN TRISOMICS OF CLARKIA UNGUICULATA

Vasek , F. C. (U. California, Riverside.) Phenotypic variation in trisomics of Clarkia unguiculata. Amer. Jour. Bot. 50(4): 308–314. 1963.—Progenies of 3n × 2n crosses included, in addition to diploids, plants trisomic for 1, 2, 3, 4, 5, 6 or 7 chromosomes. Means and variances were calculated for 15 phenotypic traits, including 3 width/length ratios, in one set of progenies, and for 10 of the traits, including 2 of the ratios, in another set of progenies. In 25 trait comparisons, including 15 different traits, the means for each chromosome number class were heterogeneous in 11 comparisons, which included 8 different traits. Single trisomics differed significantly from diploids in 5 comparisons (4 different traits). Despite these significant differences the variation followed no particular pattern except that sepal length increased and pollen fertility decreased with chromosome number, and trisomics, as a group, sometimes differed from diploids with regard to the width/length ratio of leaves or petals. The variances were heterogeneous in 5 comparisons (4 different traits). Sepal length and pollen fertility were the only traits for which single trisomics were more variable than diploids and for which the entire population was more variable than diploids. In addition, in 4 progenies of self-pollinated trisomics, diploids and trisomics (which within each progeny were trisomic for the same Chromosome) differed significantly in mean value in only 3 traits (out of 60 trait comparisons). Variances were significantly different in 6 comparisons (4 different traits) but, surprisingly, diploids were more variable than trisomics in 3 of these 6 comparisons. Except for sepal length, pollen fertility and some width/length ratios, a wide variety and number of extra chromosomes rarely had a significant effect on the mean or variability of various phenotypic traits, and single specific extra chromosomes had very little effect except sometimes on pollen fertility or an occasional ratio. A large amount of variation, probably caused by the environment and the general genetic background, may obscure possible specific trisomic phenotypes. Morphological identification of specific trisomics is considered impractical in this species.     

Trisomics from triploid-diploid crosses in self-incompatible Lycopersicum peruvianum

Summary An attempt was carried out to produce trisomics of the wild tomato L. peruvianum, to define their essential features, and to detect relationships between trisomy and the expression of self-compatibility.Triploid-diploid crosses in L. peruvianum yielded nearly 40% aneuploids. Of these, 18% were single trisomics, and the rest had 2, 3 and 4 extra chromosomes. Almost all the trisomics occurred in crosses where the triploid was used as female parent. Vigour and fertility of trisomics were not much different from those of disomics, and morphologically they were very similar.The extra chromosome was identified in three self-compatible trisomic plants through somatic and pachytene chromosome morphology. One of these plants was trisomic for chromosome 1, while the other two were trisomic for chromosome 3. In these trisomics a positive correlation was found between chromosome length and trivalent formation, but no relationship between chromosome length and frequency of laggards was observed.A series of test-crosses revealed that the capacity of the trisomics to produce seed upon selfing always resulted from alterations of the incompatibility phenotype of the style and not from competitive interaction in the pollen. Progeny analyses showed that the self-compatibility features of the trisomics were not transmitted from one generation to the next. The implications of these findings are discussed.This work has been supported by a contract between the European Communities and the CNEN. This publication is contribution no. 1458 from the Biology Division of the European Communities and contribution no. 472 from the Divisione Applicazioni delle Radiazioni del CNEN.