Creation of the technique of interspecific hybridization for breeding in cotton

The new technique of interspecific hybridization was created in Gossypium, which could remarkably overcome abortion of interspecific hybridization and hybrid sterility of F1. A large number of germplasm resources were obtained from seventy cross combinations among the cultivated species and between the cultivated and the 14 wild species, respectively. 8 varieties have been developed, of which 4 were from the cross combination of G. hirsutumXG. arboretum and the other are the first breed from the hybrids between G. hirsutum and 4 wild species, respectively. Of them Shiyuan 321 (jimian 24) is a new variety which had the highest increase in the national Yellow River Valley Regional test, with planting area added up to 933333 ha in the recent three years. The breeding system of interspecific hybridization was established.     

四个栽培棉种间的杂种F1细胞遗传学与亲缘关系研究

以棉属四个栽培棉种进行种间杂交,产生(亚洲棉×草棉)和(陆地棉×海岛棉)2个二元杂种F1及其[(亚洲棉×草棉)×(陆地棉×海岛棉)]四元杂种F1,观察和测定4个栽培棉种及其2个二元杂种F1和四元杂种F1的花粉母细胞(PMC)减数分裂的染色体行为及其花粉生活力,以研究4个栽培棉种间的亲缘关系和进化关系。结果表明,二元杂种(亚洲棉×草棉)F1的PMC减数分裂中期Ⅰ出现一个四体环,其余为二价体,染色体构型为2n=26=11Ⅱ 1Ⅳ;花粉生活力的测定表明,(亚洲棉×草棉)F1可育型花粉为50.71%,表现为典型的配子半不育特性,说明两个二倍体棉种间发生一次染色体易位。(陆地棉×海岛棉)F1以26个二价体细胞为主,但有少量的单价体、三价体以及四价体,染色体构型为2n=52=0.78Ⅰ 22.24Ⅱ 0.94Ⅲ 0.98Ⅳ。花粉生活力的测定表明,(陆地棉×海岛棉)F1可育型花粉为54.84%,可见2个四倍体棉种间亲缘关系较近,二者之间仅发生了染色体的易位或倒位。而由4个栽培种合成的四元杂种F1,其减数分裂异常,染色体丢失现象普遍,部分染色体不能联会配对,以单价体的形式存在,并出现三价体、四价体、五价体等多价体,染色体构型为2n=52=5.45Ⅰ 14.41Ⅱ 2.44Ⅲ 1.59Ⅳ 0.63Ⅴ 0.15Ⅵ,其可育花粉为6.87%。研究结果表明了4种栽培棉种之间的亲缘关系相对较近,可以通过遗传重组产生综合有4个栽培棉种性状的新种质。     

High-density Linkage Map of Cultivated Allotetraploid Cotton Based on SSR, TRAP, SRAP and AFLP Markers

A high-density linkage map was constructed for an F2 population derived from an Interspecific cross of cultivated allotetraploid species between Gossypium hirsutum L. and G. barbadense L. A total of 186 F2 individuals from the Interspecific cross of ＂CRI 36 × Hal 7124＂ were genotyped at I 252 polymorphic loci Including a novel marker system, target region amplification polymorphism （TRAP）. The map consists of 1 097 markers, including 697 simple se- quence repeats （SSRs）, 171 TRAPs, 129 sequence-related amplified polymorphisms, 98 amplified fragment length polymorphisms, and two morphological markers, and spanned 4 536.7 cM with an average genetic distance of 4.1 cM per marker. Using 45 duplicated SSR loci among chromosomes, 11 of the 13 pairs of homologous chromosomes were Identified In tetraploid cotton. This map will provide an essential resource for high resolution mapping of quantitative trait loci and molecular breeding in cotton.     

Esterase Isozyme analyses of the Species and Their Varieties of the Genus Gossypium

The isozyme make up of esterases of the seeds from fifteen species and twenty-three cultivar of Gossypium was analyzed by isoelectrofocusing. The experimental results are summarized as follows: 1. Differeces were observed in the number of esterase isozyme bands among the species of different genome groups. The cultivated species, G. hirsutum (AD)1 gave rise to 46 isozyme bands, the most among the species of the genus Gossypium. G. barba- dense (AD)2, G. arboreum (A2) and G. herbaceum (A1) gave rise to 42, 40 and 38 bands, respectively. In wild species, G. australe (C3) had 20 esterase bands, the least in all species of Gossypium. The bands given rise from other wild species ranged from 26 to 40. 2. Each species of every genome groups had its marker bands. The results were in agreement with the traditional classification and provided some biochemical evidence for modern classification of Gossypium. 3. It was clear that all cotton species of different genome groups contain 5 main isozyme bands, viz. PI=3.85, 4.61, 5.48, 5.73 and 5.91 in the zymograms. In other words, these zymograms are common characters of Gossypium. 4. The esterase of 23 cultivers in four cultivated species studied showed that no variation in isozyme patterns existed within one species, except the disease-resistant variety Hea-7124 which differs from other 4 cultivars of G. barbadense.     

大豆优异种质资源的利用与创新

黑龙江省农科院利用已获得的具有野生大豆(含半野生大豆)多花荚、多分枝、高蛋白等有益性状基因的优异种间杂交新种质(G.max×G.soja)与栽培大豆(G.max)回交,一方面继续拓宽大豆育种遗传基础,另一方面改善现有种间杂交种质的农艺性状和品质,并提高产量水平,已选育出外贸制纳豆、豆芽、制酱及青瓤黑豆等特用大豆品种(系).实践表明,利用野生大豆及种间杂交新种质,对拓宽大豆育种遗传基础,提高大豆育成品种水平,尤其对特用大豆品种(系)的选育是有效可行的.     

Structural variation of mitochondrial genomes sheds light on evolutionary history of soybeans

The architecture and genetic diversity of mitogenome (mtDNA) are largely unknown in cultivated soybean (Glycine max), which is domesticated from the wild progenitor, Glycine soja, 5000 years ago. Here, we de novo assembled the mitogenome of the cultivar ‘Williams 82’ (Wm82_mtDNA) with Illumina PE300 deep sequencing data, and verified it with polymerase chain reaction (PCR) and Southern blot analyses. Wm82_mtDNA maps as two autonomous circular chromosomes (370 871-bp Chr-m1 and 62 661-bp Chr-m2). Its structure is extensively divergent from that of the mono-chromosomal mitogenome reported in the landrace ‘Aiganhuang’ (AGH_mtDNA). Synteny analysis showed that the structural variations (SVs) between two genomes are mainly attributed to ectopic and illegitimate recombination. Moreover, Wm82_mtDNA and AGH_mtDNA each possess six and four specific regions, which are absent in their counterparts and likely result from differential sequence-loss events. Mitogenome SV was further studied in 39 wild and 182 cultivated soybean accessions distributed world-widely with PCR/Southern analyses or a comparable in silico analysis. The results classified both wild and cultivated soybeans into five cytoplasmic groups, named as GSa–GSe and G1–G5; ‘Williams 82’ and ‘Aiganhuang’ belong to G1 and G5, respectively. Notably, except for members in GSe and G5, all accessions carry a bi-chromosomal mitogenome with a common Chr-m2. Phylogenetic analyses based on mtDNA structures and chloroplast gene sequences both inferred that G1–G3, representing >90% of cultigens, likely inherited cytoplasm from the ancestor of domestic soybean, while G4 and G5 likely inherited cytoplasm from wild soybeans carrying GSa- and GSe-like cytoplasm through interspecific hybridization, offering new insights into soybean cultivation history.     

Characterization of Interspecific Hybrids Between Oryza sativa L. and Three Wild Rice Species of China by Genomic In Situ Hybridization

In the genus Oryza, interspecific hybrids are useful bridges for transferring the desired genes from wild species to cultivated rice （Oryza sativa L.）. In the present study, hybrids between O. sativa （AA genome） and three Chinese wild rices, namely O. rufipogon （AA genome）, O. officinalis （CC genome）, and O. meyeriana （GG genome）, were produced. Agricultural traits of the F1 hybrids surveyed were intermediate between their parents and appreciably resembled wild rice parents. Except for the O. sativa × O. rufipogon hybrid, the other F1 hybrids were completely sterile. Genomic in situ hybridization （GISH） was used for hybrid verification. Wild rice genomic DNAs were used as probes and cultivated rice DNA was used as a block. With the exception of O. rufipogon chromosomes, this method distinguished the other two wild rice and cultivated rice chromosomes at the stage of mitotic metaphase with different blocking ratios. The results suggest that a more distant phylogenetic relationship exists between O. meyeriana and O. sativa and that O. rufipogon and O. sativa share a high degree of sequence homology. The average mitotic chromosome length of O. officinalis and O. meyeriana was 1.25- and 1.51-fold that of O. sativa, respectively. 4＇,6＇-Diamidino- 2-phenylindole staining showed that the chromosomes of O. officinalis and O. meyeriana harbored more heterochromatin, suggesting that the C and G genomes were amplified with repetitive sequences compared with the A genome. Although chromocenters formed by chromatin compaction were detected with wild rice-specific signals corresponding to the C and G genomes in discrete domains of the F1 hybrid interphase nuclei, the size and number of O. meyeriana chromocenters were bigger and greater than those of O. officinalis. The present results provide an important understanding of the genomic relationships and a tool for the transfer of useful genes from three native wild rice species in China to cultivars.     

Hybridization between Gossypium herbaceum and Gossypium stocksii through embryo rescue

INTRODUCTIONGOSndumherbaceuminoneofthetwo'A'genomediploidcultivatedspeciesofcotton.ItisgrowninsomepartsofcentralIndia,esDeciallyasarainfedcrop.G-sto~isawiIdspeciesbelongingto'E'ge11omeandisfoundinWestAsia.Thisspecieshasaverygoodrootsystemandistoleranttodrought[1]-Thus,thehybridizationbetweenG.herbaceumandG.stock8iisdesiredtodevelopdrought-tolerantvarietiesinG.herbaceum.Theattemptstoproduceinterspecifichybridsbytheconventionalmethodsareoftenunsuccessfulduetotheformationofunderdevel-op…     

陆地棉×比克氏棉育成种质系的同工酶和RAPD分析

为了从分子水平上检验野生棉遗传特性向陆地棉转育的结果以及育成种质之间的遗传差异,通过等电聚焦电泳和RAPD技术,对来自科遗181陆地棉品系与野生比克氏棉杂交后代的6个遗传稳定的不同种质系及其亲本的过氧化物酶同工酶图谱和DNA指纹图谱进行了分析。结果如下（1）6个种质系的基本酶谱特征均倾向于陆地棉亲本,但在其中2个种质系的过氧化物酶图谱中,观察到各具有1条等电点值（PI）为4.85的野生亲本的特征带;（2）DNA指纹图谱的分析表明,不同种质系之间在基因组水平上具有高度的异质性。并且在OPO10和OPO112个引物的扩增图谱中观察到4个育成种质系具有野生比克氏棉亲本的特征带。     

远缘杂交和异源多倍体化技术在水稻育种中的应用

从野生稻遗传资源在育种中的作用出发,概述了栽培稻与野生稻远缘杂交和多倍体化在水稻育种中的应用。对远缘杂交中的杂交不亲和性以及杂种不育等问题采用激素处理、胚挽救等途径解决,对所获杂种从形态学、细胞学、生物化学以及分子生物学等多方面鉴定,对栽野杂种存在的野生性状通过选择与改造相结合的方法而淘汰,对其有利基因则加以选择和聚合以获得稳定优良品种。这些从理论上和实践上证明远缘杂交和多倍体化相结合的异源多倍体化是获得高产优质水稻新品种的一条新途径。     

The Inheritance of Gossypol Level in Gossypium II: Inheritance of Seed Gossypol in Two Strains of Cultivated GOSSYPIUM BARBADENSE L

Two strains of cultivated Gossypium barbadense L., Sea Island AS-2 and Pima S-4, were used to study the effects of alleles at two loci on the production and/or storage of gossypol in mature embryos. The normal alleles, Gl(2) and Gl(3), are "native" to G. barbadense, whereas the mutant alleles, gl(2) and gl(3), were introduced from Gossypium hirsutum L. through backcrossing. Each strain was grown in three replications per trial, and one, Sea Island AS-2, was grown in three environments. Each experiment consisted of all possible crosses, including reciprocals, of the four true-breeding genotypes, plus parents. Additive effects accounted for more than 90% of the total genetic variance for seed gossypol level in all trials. Epistatic effects, though small, were frequently significant. In G. barbadense Gl(2) and Gl(3) were associated with the production of similar amounts of gossypol, whereas previous trials with cultivated varieties of G. hirsutum showed that Gl(2) was more than twice as expressive as Gl(3). The greater average productivity of seed gossypol in cultivated G. barbadense, as compared with G. hirsutum, was attributed to greater activity at the Gl(3) locus in the former species.     

80份甘蔗种质RAMP标记遗传多样性分析

采用RAMP分子标记技术对80份甘蔗种质(32份祖亲种、48份栽培品种或品系)的遗传基础进行了分析。从30对引物组合中筛选出4对多态性较强引物,构建了甘蔗80份种质的RAMP指纹图谱,这四对引物组合共扩增出84条带,其多态性为91.7%。80份种质的遗传相似系数变化范围在0.433～0.988,平均0.710。聚类分析表明,随着相似系数结合线的不同,可分别将参试的甘蔗种质从属间(甘蔗属与斑茅种)、野生种(割手密种、大茎野生种、印度种、中国种)与栽培种(热带种)间、栽培种与杂交栽培品种(或品系)间区别开来。各祖亲种与杂交栽培品种(或品系)的遗传相似性由大到小依次为热带种>印度种和中国种>大茎野生种＞云南割手密种＞其它割手密种＞斑茅。另外,本试验首次利用RAMP标记,获得了部分热带种、野生种及斑茅种特异片段,并发现这些特异片段能不同程度地在具有其血缘的栽培种中得到传递。     

Genetic relationships among the annual species of Cicer L.

Summary Genetic relationships between 7 annual species of the genus Cicer, including the cultivated chickpea, have been studied. These species were assigned to 3 crossability groups. In each group interspecific hybrids could be obtained but their fertility differed considerably in the various cross combinations. Crosses between members of different groups yielded no viable seeds. The possibility of gene transfer from the wild species to the cultivated chickpea C. arietinum was also assessed. Only two species could be considered for this purpose, C. reticulatum, which is the wild progenitor of the cultivated species, and C. echinospermum, which is in the secondary gene pool of C. arietinum. A unique postzygotic reproductive barrier mechanism was found between the members of Group II, C. judaicum, C. pinnatifidum and C. bijugum. It is based on a disharmony in the growth rate of the stigma and the anthers at the time of anthesis of the F₁ interspecific hybrid so that selfpollination is avoided. It is proposed that this kind of mechanism has been involved only when an effective spatial isolation between the three species had been obtained.     

Partial hybridization in wide crosses between cultivated sunflower and the perennial Helianthus species H. mollis and H. orgyalis

To obtain introgressed sunflower lines with improved disease resistance, interspecific crosses were performed with foreign perennial species. We report on several unusual features displayed by these hybrid plants. The methods used to produce the kernels affected yield and genotypes of progeny. Phenotypic traits and DNA markers were investigated in 97 plants derived from cross-pollination between annual diploid cultivated sunflower (Helianthus annuus) and the perennial diploid species H. mollis or H. orgyalis, and the reverse reciprocal crosses. The level of hybridization in progeny was determined using RAPD and RFLP markers. Hybridization was performed by leaving embryos to develop normally on the head (classical crossing) or using embryo rescue. All observed plants derived from H. mollis were diploid (2n = 34). Phenotypes were predominantly similar to the female when cultivated sunflower was the female parent. Progeny from crosses using a wild species as the female parent resembled that parent. Thus, reciprocal crosses led to different progeny. F1 sister progeny shared different sets of molecular markers representing a few of those of the wild species used as the pollen donor. Our results indicate mechanisms leading to the unusual event of partial hybridization. Possible mechanisms behind these unusual events and their possible impact on evolution are discussed.     

Fertile allotetraploid from the cross betweenPhaseolus coccineus L. andPhaseolus acutifolius A. Gray

Summary As somatic hybridization and genetic transformation are not yet applicable to beans, a programme of hybridization between a male sterile line ofP. coccineus and a wild genotype ofP. acutifolius var.tenuifolius was carried out in order to introduce useful characters from the wild parent into the genome of the cultivated species. This interspecific cross is of particular interest sinceP. acutifolius is a source of resistance to many diseases, drought and high temperature. The difficulties in producing these hybrids were overcome by repeated pollinations and with the help of embryo culture. The F₁ hybrid shows a high sterility which may be explained by the poor pollen quality and the presence of a chromosomic asynapsis at meiosis. Fertile allotetraploids (Co) were successfully produced in progeny from colchicine treated cuttings of F₁ hybrids. Several (C₂) mature seeds were harvested from selfed allotetraploid plants.Abbreviations Co initial allotetraploid plants - C₁, C₂ first and second allotetraploid generation - PMC pollen mother cell     

甜瓜属植物种间杂交研究进展

在甜瓜属野生种Cucumis hystrix Chakr. 和栽培黄瓜之间的种间杂交取得成功的基础上,简要回顾了甜瓜属植物种质资源和系统学的研究情况,然后从甜瓜属植物种间杂交的概况、种间杂交的障碍及其解决途径等三个方面,回顾和讨论了甜瓜属植物的种间杂交的研究进展,并对进一步通过种间杂交研究利用甜瓜属野生植物资源的前景进行了展望。     

利用野生大豆资源创新优质抗病大豆新种质

利用野生大豆与栽培大豆种间杂交中间材料与高产栽培大豆回交转育,创新选育出蛋白质含量45％以上,蛋脂总含量63％以上,分别抗大豆疫霉根腐病,抗大豆灰斑病,农艺性状优良的大豆创新种质资源3份。其中,龙品8802-1抗大豆疫霉根腐病兼抗大豆灰斑病,蛋白质含量45．64％,脂肪含量18．42％,蛋脂总含量64．06％;龙品01-757抗大豆灰斑病,蛋白质含量45．99％,脂肪含量19．4％,蛋脂总含量65．39％;龙品9501,中抗大豆灰斑病,蛋白质含量45．11％,脂肪含量18．32％,蛋脂总含量63．43％。研究结果表明,利用含有野生大豆血缘的种间杂交材料与高产栽培大豆回交,是拓宽大豆遗传基础,创新选育优质、抗病、农艺性状优良大豆新种质资源的有效途径。     

Exogenous hormone applications at pollination for in vitro and in vivo production of cotton interspecific hybrids

Interspecific hybridization of cotton (Gossypium) has been assisted by ovule and embryo culture. These culture methods were compared to exogenous hormone applications for efficient plant production from crosses between Upland cotton, G. hirsutum L., as the maternal parent, and various diploid and tetraploid wild species as the pollen donor. The best exogenous hormone treatment resulted in an average production of five seeds per boll and 4% boll abscission. Generally, exogenous hormones used with standard hybridization techniques were superior to in vitro methods, but for some crosses, embryo culture following hormone applications was warranted.Abbreviations GA gibberellic acid, >90% A₃ - NAA 1-naphthaleneacetic acid - NOA 2-naphthoxyacetic acid.