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1.
Marinês Bastianel Mariângela Cristofani-Yaly Antonio Carlos de Oliveira Juliana Freitas-Astúa Antonio Augusto Franco Garcia Marcos Deon Vilela de Resende Vandeclei Rodrigues Marcos Antônio Machado 《Euphytica》2009,169(1):101-111
Leprosis, caused by citrus leprosis virus (CiLV) and transmitted by the tenuipalpid mite Brevipalpus phoenicis, is one of the most important viruses of citrus in the Americas. Sweet oranges (Citrus sinensis L. Osb.) are highly susceptible to CiLV, while mandarins (C. reticulata Blanco) and some of their hybrids have higher tolerance or resistance to this disease. The mechanisms involved in the resistance
and its inheritance are still largely unknown. To study the quantitative trait loci (QTL; quantitative trait loci) associated
with the resistance to CiLV, progeny analyses were established with 143 hybrid individuals of ‘Pêra’ sweet orange (C. sinensis L. Osb.) and ‘Murcott’ tangor (C. reticulata Blanco × C. sinensis L. Osb.) from controlled crossings. Disease assessment of the hybrid individuals was conducted by infesting the plants with
viruliferous mites in the field. The experiment consisted of a randomized completely block design with ten replicates. The
evaluated phenotypic traits were incidence and severity of the disease on leaves and branches, for a period of 3 years. The
MapQTL™ v.4.0 software was used for the identification and location of possible QTL associated with resistance to CiLV on
a genetic map obtained from 260 AFLP and 5 RAPD markers. Only consistent QTLs from different phenotypic traits and years of
evaluation, with the critical LOD scores to determine the presence or absence of each QTL calculated through the random permutation
test, were considered. A QTL was observed and had a significant effect on the phenotypic variation, ranging from 79.4 to 84%
depending on which trait (incidence or severity) was assessed. This suggests that few genes are involved in the genetic resistance
of citrus to CiLV. 相似文献
2.
Eileen Azevedo Santos Margarete Magalhães Souza Priscilla Patrocínio Abreu Leo Duc Haa Carson Schwartzhaupt da Conceição Ioná Santos Araújo Alexandre Pio Viana Alex-Alan Furtado de Almeida Jôsie Cloviane de Oliveira Freitas 《Euphytica》2012,184(3):389-399
Three new varieties of Passiflora hybrids were developed from crosses between P. sublanceolata J. M. MacDougal (ex P. palmeri var. sublanceolata Killip) versus P. foetida var. foetida L. Twenty putative hybrids were analyzed. Hybridizations were confirmed by RAPD and SSR markers. The RAPD primer UBC11 (5′-CCGGCCTTAC-3′)
generated informative bands. The SSR primer A08FP1 amplified species-specific fragments and heterozygote status was observed
with the two parent bands 240 and 280 bp. The molecular markers generated by primers were analyzed in terms of the presence
or absence of specific informative bands. The morphological characterization of the hybrids enabled their differentiation
into three groups, identified as: (1) Passiflora ‘Alva’, composed of five hybrid plants with white flowers, large corona, light purple filaments at base, white and purple/white
banding to apex; (2) P. ‘Aninha’, composed of six hybrid plants with pale pink flowers, corona filaments reddish/purple at base, white, purple/white
banding to apex; (3) P. ‘Priscilla’, composed of nine hybrid plants with white flowers, small corona, filaments dark purple at base, white and purple
to apex. The genomic homology of parent plants was verified by cytogenetic analysis. Both parents were 2n = 22. Meiosis was regular in genitors and hybrids. Aneuploidy was observed at hybrid groups P. ‘Alva’ and P. ‘Priscilla’ (2n = 20). Other authors had already observed the same number of chromosomes for some P. foetida genotypes. Obtaining valuable interspecific hybrids opens up new perspectives to offer opportunities in agribusiness for
producers and to arouse the interest of consumers into using passion flowers in the Brazilian ornamental plant market. 相似文献
3.
Protoplasts from cell suspension cultures of ‘Bonnaza’ navel orange (Citrus sinensis (L.) Osbeck) were electrically fused with mesophyll protoplasts isolated from seedless ‘Red Blush’ grapefruit (Citrusparadisi). After 6 months of culture, a total of 20 plants were regenerated. Root tip chromosome counting revealed that 4 of them
were tetraploids (2n = 4x = 36)and the rest were diploids (2n = 2x = 18) morphologically resembling the mesophyll parent.
After 6 months of transplantation into the greenhouse, 4 of the diploidmesophyll regenerants unexpectedly flowered, but this
phenomenon disappeared in the next year. This is the first report of precocious flowering in citrus via protoplast fusion.
RAPD analysis further confirmed that the tetraploid regenerants were somatic hybrids while the diploid regenerants were mesophyll
parent type. This somatic hybrid will be utilized as a possible pollen parent for improving the seedy pummelo cultivars in
China by producing triploid seedless pummelo hybrid. The mechanism of early flowering was also discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
4.
Sergio Pietro Ferrante Sergio Lucretti Silvia Reale Alessandro De Patrizio Loredana Abbate Nicasio Tusa Maria-Teresa Scarano 《Euphytica》2010,173(2):223-233
We report the accurate determination of the allelic configurations of a total of eight new citrus tetraploid hybrids by means
of SSR analysis, coupled with capillary electrophoresis, and PCR based dosage effects. Tetraploid hybrids were spontaneously
obtained from different interploid crosses (2x × 4x) between diploid ‘Femminello’ lemon and the allotetraploid somatic hybrid
(2n = 4x = 36) ‘Key’ lime + ‘Valencia’ orange, and between diploid ‘Wilking’ and ‘Fortune’ mandarins and an autotetraploid ‘Dancy’
mandarin (2n = 4x = 36). To understand the opportunity to employ them in further backcross programs, the cytological mechanisms underlying
their ploidy level were unambiguously determined using six SSR primers. PCR conditions were optimized and skewness in template/product
ratios were verified. Tetraploid allelic configurations were determined from PCR based dosage effects using electropherogram
peak heights to estimate the copy number per allele. In all the tetraploid hybrids we found out that diploginy (2n eggs) has occurred, contributing the extra haploid genome in the tetraploids. According to the marker genotypes, it was further
inferred that the 2n eggs in ‘Femminello’ lemon resulted from first division restitution (FDR), while in ‘Wilking’ and ‘Fortune’ mandarins 2n eggs occurred in second division restitution (SDR). These new genotypes, with their improved genetic female background, can
be therefore considered very valuable in our citrus genetic improvement program as pollen donors in backcrosses suitable to
eliminate negative traits. 相似文献
5.
Valdenice Moreira Novelli Marco Aurélio Takita Marcos Antonio Machado 《Euphytica》2004,138(3):227-237
Most of the cultivated species of citrus have narrow genetic basis. Relationships among species and cultivars are obscured by sexual compatibility, polyembryony, apomixis and a high incidence of somatic mutations. DNA analysis is crucial in genetic studies not only for citrus breeding programs but also for characterization of hybrids and species. In this paper, single nucleotide polymorphisms (SNPs) were investigated in 58 accessions of Citrus, hybrids and related genera. Genomic sequences of Pêra IAC sweet orange (Citrus sinensis L. Osbeck) were used for primer design and selection of sequence tagged sites (STSs) for identification of SNPs. Analysis of 36 STSs showed identical sequences among 40 of the 41 sweet orange accessions studied. However, these accessions were heterozygous for many SNPs. Ten selected STSs were analyzed in 17 additional accessions from 13 species and hybrids. Comparing to the Pêra IAC sweet orange accession, a total of 150 polymorphic nucleotides were identified and most of the alterations were transitions (52.7%). The greatest number of SNPs was observed in Poncirus trifoliata (L.) Raf. and the smallest in Ponkan mandarin (Citrus reticulata Blanco). At the intra-specific level, Baía Gigante (Citrus sinensis L. Osbeck) was the only sweet orange accession with a divergent SNPs genotype, which corroborates the hypothesis of a hybrid origin for this accession. Although the STSs analyzed represent randomly sampled genomic sequences, they provided consistent information about the level of polymorphism and showed the potential of SNPs markers for characterization and phylogenetic studies. 相似文献
6.
Arancha Arbeloa M. E. Daorden E. García A. Wünsch J. I. Hormaza J. A. Marín 《Euphytica》2006,147(3):389-394
The incidence of fortuitous pollination on interspecific hybridizations of the plum rootstock Myrobalan with the apricot cultivars
‘Moniquí’ and ‘Moniquí Borde’ was assessed in this work. Progeny was originated through hand pollination of emasculated flowers
of three Myrobalan clones, without bagging, in 1998 and 1999. Fruit set was low and variable among years (1.8–8.0%), but higher
than the level of accidental pollination measured with emasculated and non-pollinated flowers (1.2%). Molecular characterization
of the progeny was performed with three SSR markers showing that only 28% of the seedlings, obtained by in vitro germination
and culture of immature embryos, were hybrids. This represents a lower percentage than expected, and is explained here by
the low viability of hybrid embryos and seedlings. The use of molecular markers is discussed in terms of a convenient method
for an early identification of putative hybrids in breeding programs with low setting crosses, where the proportion of non-hybrids
is magnified. 相似文献
7.
Sequence-related amplified polymorphism (SRAP), simple sequence repeats (SSR), inter-simple sequence repeat (ISSR), peroxidase
gene polymorphism (POGP), resistant gene analog (RGA), randomly amplified polymorphic DNA (RAPD), and a morphological marker,
Alternaria brown spot resistance gene of citrus named as Cabsr caused by (Alternaria alternata f. sp. Citri) were used to establish genetic linkage map of citrus using a population of 164 F1 individuals derived between ‘Clementine’ mandarin (Citrus reticulata Blanco ‘Clementine) and ‘Orlando’ tangelo’ (C. paradisi Macf. ‘Duncan’ × C. reticulata Blanco ‘Dancy’). A total of 609 markers, including 385 SRAP, 97 RAPD, 95 SSR, 18 ISSR, 12 POGP, and 2 RGA markers were used
in linkage analysis. The ‘Clementine’ linkage map has 215 markers, comprising 144 testcross and 71 intercross markers placed
in nine linkage groups. The ‘Clementine’ linkage map covered 858 cM with and average map distance of 3.5 cM between adjacent
markers. The ‘Orlando’ linkage map has 189 markers, comprising 126 testcross and 61 intercross markers placed in nine linkage
groups. The ‘Orlando’ linkage map covered 886 cM with an average map distance of 3.9 cM between adjacent markers. Segregation
ratios for Cabsr were not significantly different from 1:1, suggesting that this trait is controlled by a single locus. This locus was placed
in ‘Orlando’ linkage group 1. The new map has an improved distribution of markers along the linkage groups with fewer gaps.
Combining different marker systems in linkage mapping studies may give better genome coverage due to their chromosomal target
site differences, therefore fewer gaps in linkage groups. 相似文献
8.
Intergeneric sexual hybridizations were conducted between two genera of Rutaceae, with Satsuma mandarin (Citrus unshiu Marc) and Red tangerine (C. reticulata Blanco) as maternal parents, and Poncirus trifoliata (L.) Raf as the paternal parent, in an effort to generate hybrid populations for both molecular mapping and rootstock breeding.
Embryo rescue is important for citrus sexual breeding because polyembryony can interfere with hybrid embryo recovery. Immature
embryos of 80, 85, 90 days after pollination (DAP) from the Satsuma mandarin (S) × trifoliate orange (P) cross, 80 and 85
DAP from the Red tangerine (R) × trifoliate orange (P) cross, were cultured on MG1.0 medium consisting of MT basal medium
supplemented with 1.0 mg l−1 GA3 and 4% sucrose. The results showed that 80 DAP was the optimal time for embryo rescue of the tested crosses, as evidenced
by embryos at this stage exhibiting high germination rates, 37.3% for S × P and 51.3% for R × P. Among the eight tested media,
MT medium supplemented with 0.5 mg l−1 GA3 was the best one for Satsuma mandarin, and MT plus 1.0 mg l−1 GA3 for Red tangerine. A total of 85 plants were obtained from S × P, and 340 from R × P. Out of them, 44 progenies from S × P
and 111 from R × P were sufficiently confirmed to be hybrids by morphological characterization and SSR analysis. In addition,
two hybrid callus lines were obtained from S × P and R × P respectively. 相似文献
9.
Most commercial citrus fruit species and cultivars are inter- and intra-specific hybrids. Conventional hybridization in citrus is largely handicapped by apomixis and long juvenility. As an alternative, somatic hybridization via protoplast fusion has been employed to create novel citrus germplasm. Witches' broom disease of lime (WBDL) emerged in Oman during the 1970s, which has been spreading to the neighboring countries. The disease is extremely destructive. A possible solution to the WBDL problem is to develop resistant hybrids. Resistance is available among the citrus relatives of lime i.e., sweet orange. Somatic hybrids combining sweet orange with lime have been produced but the fruit characteristics are different from lime. Herein, we report the development of somatic hybrids between a progenitor of lime (Citrus micrantha) and sweet orange (Citrus sinensis) in efforts to recreate a lime-like fruit using sweet orange as a donor of disease resistance gene(s). Successful somatic hybridization was verified by ploidy analyses using flow cytometry and RAPD analyses. This is the first report of using a progenitor species in somatic hybridization experiments in efforts to resynthesize an improved lime. 相似文献
10.
Ceratocystis canker, which is caused by the fungus Ceratocystis fimbriata Ellis et Halsted, is one of the most severe diseases of the common fig (Ficus carica L.). In contrast, the wild fig species F. erecta Thunb. is resistant to this fungus. We performed interspecific hybridization between the common fig (seed parent) and F. erecta (pollen parent) through artificial pollination. Even though hybrid seeds showed high germination rates, the seedling survival
rates were low. All of the seedlings contained the expected simple sequence repeat (SSR) alleles from both common fig and
F. erecta at each of the three loci tested, thus confirming the parent–offspring relationships of the interspecific hybrids. The leaf
morphological characters of hybrid seedlings were intermediate between those of the parents. Cuttings of cultivars of common
fig, F. erecta, and hybrid seedlings were inoculated with C. fimbriata by direct wounding of the shoot. All of the common fig cultivars tested withered and died within 10 weeks. Leaves and shoots
of the hybrids and F. erecta were healthy 100 days after inoculation. Our results suggest that interspecific hybridization between the common fig and
the wild species F. erecta is a breakthrough in the breeding of a new fig rootstock source with resistance to Ceratocystis canker. 相似文献
11.
Successful selection of interspecific hybrid progenies with superior ability to regenerate shoots from apical meristems was
performed in sunflower which now allows for the development of lines for improved biotechnological applications. Early generations
of interspecific hybrids originating from crosses between the two H. annuus CMS lines ‘HA89’ and ‘Baso’, and 9 wild species were screened for their ability to regenerate in vitro. Evaluation of 36 progenies allowed to identify seven progenies from crosses involving H. mollis, H. giganteus, H. strumosus, and H. decapetalus which showed a significantly higher regeneration potential than the commercial hybrid ‘Albena’ regarding the number of shoots
per explant. Among these progenies, 47.2 to 62.4% of explants produced shoots with an average of 2.3 to 3.5 shoots per cultured
explant. Regeneration in vitro was significantly determined by the genotype. More than half of the investigated interspecific hybrids performed better than
the inbred ‘HA89’ demonstrating that the high regeneration potential available in the wild species can be efficiently transferred
to cultivated sunflower. The seven progenies with high regeneration potential in vitro were characterised by agronomic performance in the field. Two of the interspecific hybrids derived from H. strumosus and H. decapetalus not only showed a superior regeneration potential but also proved to be competitive to commercial hybrids with regard to
important agronomic traits, e.g. fat content and TGW.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
12.
Quantitative evaluation of the degree of sprout leaf bending of rice cultivars using P-type Fourier descriptors and principal component analysis 总被引:1,自引:0,他引:1
For decades, seedling peaches have been used as the standard rootstock in California almond orchards. Vigorous, deep rooted
trees are needed in almond orchards for maximum yields and to withstand the annual tree-shaking at harvest. Currently, researchers
are actively evaluating rootstocks for almonds in field trials and in various screening protocols. In this study, seedling
rootstocks, obtained from male-sterile advanced generation peach-almond (PEAL) hybrid mother trees, were compared with ‘Nemaguard’
peach seedlings for emergence in the nursery row, trunk caliper at propagation time, and end of season dormant above ground
tree weight. Seedling emergence was affected significantly (P ≤ 0.05) by seed source, as was trunk caliper and end of season dormant above ground tree weight. Trunk caliper and dormant
above ground tree weight were also affected significantly (P ≤ 0.05) by planting year. Results obtained in this study demonstrate the enhanced first year growth from seedlings of advanced
generation PEAL hybrids, as compared to ‘Nemaguard’ seedlings. Seedling emergence in the rootstock bed was not affected significantly
by planting year. Advanced generation PEAL hybrid seedlings were ready for June-budding at an earlier date compared to ‘Nemaguard’
seedlings, providing the potential for larger-sized finished nursery stock by the end of the growing season. Due to the male-sterile
status of the advanced generation PEAL mother trees, bloom periods of several root-knot nematode resistant rootstock cultivars
were examined for their degree of synchronicity with the mother trees. The examined rootstocks and mother trees varied in
both chill hour and post-chill heat requirements necessary to effect bloom. ‘Flordaguard’ peach rootstock began bloom in advance
of the male-sterile mother trees, whereas the bloom period of ‘Tsukuba No. 4’ occurred well after, suggesting they would not
be effective synchronous pollenizers for consistent hybrid seed production. Based on more limited flowering period data, better
bloom synchronicity was achieved with a Tsukuba No. 4 X Flordaguard hybrid. 相似文献
13.
Interspecific hybridisation between Hibiscus syriacus, Hibiscus sinosyriacus and Hibiscus paramutabilis 总被引:1,自引:0,他引:1
Interspecific hybrids from crosses between H. syriacus × H. paramutabilis and H. syriacus × H. sinosyriacus were obtained. In both cases unilateral incongruity was observed and reciprocal crosses yielded no fruits. In vitro embryo
rescue, 11 weeks after pollination, increased the germination capacity of H. syriacus × H. sinosyriacus embryos, while this was not the case for H. syriacus × H. paramutabilis embryos. However, a lot of the generated H. syriacus × H. sinosyriacus seedlings were lost due to variegated and total albinism. In the progeny of H. syriacus ‘Oiseau Bleu’ × H. paramutabilis about 95% of the seedlings had an intermediate flower and leaf morphology compared to both parent plants. Leaves on the adult
F1 hybrids showed a polymorphism. In total four different leaf types could be observed on the same plant. This leaf polymorphism
also was seen in the progeny of H. syriacus ‘Melwhite’ × H. sinosyriacus ‘Lilac Queen’. In this progeny about 50% of the seedlings had an intermediate flower and leaf morphology compared with the
parent plants. The hybrid nature of the seedlings of both progenies was also confirmed by AFLP analysis. Despite the low germination
vigour of the pollen of the hybrids, a small F2 generation was obtained from H. syriacus ‘Oiseau Bleu’ × H. paramutabilis. 相似文献
14.
Squash silverleaf (SSL), caused by the silverleaf whitefly [Bemisia argentifolii (formerly known as Bemisia tabaci Gennadius, B strain)], is an important physiological disorder that affects squash (Cucurbita spp.) by reducing yield potential. Breeding squash with resistance to SSL disorder can be facilitated by using marker-assisted
selection (MAS). Resistance to SSL disorder, in Cucurbita pepo, is conferred by a single recessive gene (sl). The objective of this study was to identify molecular markers associated with resistance. A zucchini squash, SSL disorder
resistant breeding line, ‘Zuc76’ (sl/sl) and a SSL disorder susceptible zucchini cultivar ‘Black Beauty’ (Sl/Sl) were screened with 1,152 randomly amplified polymorphic DNA (RAPD) primers and 432 simple sequence repeat (SSR) markers
to identify polymorphisms. Using F2 and BC1 progeny segregating for SSL disorder resistance, three RAPD (OPC07, OPL07 and OPBC16) primers and one SSR (M121) marker were
found associated with sl. Fragments amplified by RAPD primer OPC07 was linked in coupling phase to sl, whereas RAPD primer OPL07 was linked in repulsion phase. RAPD primer OPBC16 and SSR marker M121 were co-dominant. The allelic
order of these loci was found to be M121–sl–OPC07–OPL07–OPBC16. The closest marker to sl is M121 with an estimated genetic distance of 3.3 cM. The markers identified in this study will be useful for breeding summer
squash (C. pepo) for SSL disorder resistance derived from zucchini squash breeding line ‘Zuc76’. 相似文献
15.
Lei Zhang Zuozhou Li Yanchang Wang Zhengwang Jiang Shengmei Wang Hongwen Huang 《Euphytica》2010,175(1):133-143
Seedlings derived from an Actinidia interspecific cross between the hexaploid Actinidia chinensis var. deliciosa ‘Jinkui’ and the diploid male A. eriantha × A. chinensis var. chinensis ‘Chaohong’ hybrid were analyzed using flow cytometry, SSR markers and phenotypic observations. The results show that the
leaf vitamin C content of this hybrid population has a mid-parent heterosis. Separation of flower color in the progeny was
also observed, progeny with red flowers lighter than ‘Chaohong’, white flowers as in ‘Jinkui’ and intermediate types with
a red base to the petals and white margins were all present. Flow cytometry analysis confirmed that most of the progeny were
tetraploids, and molecular marker data showed that most of these tetraploid progeny had three alleles from the hexaploid parent
and one allele from the diploid parent. UPGMA analysis based on the SSR markers showed that the diploid parent was completely
separated from the hexaploid parent and all the progeny. 相似文献
16.
Interspecific hybridization was carried out between Lilium longiflorum and L. lophophorum var. linearifolium by using the cut style method of pollination, as a contrast, intraspecific hybridization between L. longiflorum ‘Gelria’ and L. longiflorum was also made, but no mature seeds and offspring were obtained from the two combinations under in vivo condition. Ovules
excised from each carpel 5–35 days after pollination (DAP) were cultured on B5 or half-strength B5 medium containing sucrose
at different concentrations in vitro. In L. longiflorum × L. lophophorum var. linearifolium, only 1.17% of ovules excised at 10 DAP developed into seedlings, and in L. longiflorum ‘Gelria’ × L. longiflorum, only 0.99% of ovules excised at 25 DAP developed into seedlings; none of the ovules excised at other different DAP in the
two cross combinations produced any seedlings. The results showed that interspecific hybridization had a more serious post-fertilization
barrier than the intraspecific hybridization, and that a lower concentration (3%) of sucrose led to better embryo development
and higher percentage of seedlings in ovule cultures. All hybrid seedlings obtained were successfully transplanted to soil
and grew normally. The progenies investigated were identified as true hybrids based on inter-simple sequence repeat (ISSR)
analysis. 相似文献
17.
Interspecific hybridization of various tuberous Begonia species hybrids with Begonia socotrana results in so-called ‘Elatior’-begonias hybrids (B. × hiemalis Fotsch). In our study, genomic in situ hybridization (GISH) has been employed to assess the genome composition in eleven
‘Elatior’-begonias hybrids and their ancestor genotypes. Genomic DNA of tuberous Begonia was sonicated to 1–10-kb fragments,
labelled by nick translation with digoxigenin-11-dUTP and used as a probe whereas B. socotrana DNA was autoclaved to 100 bp fragments and used as block. The genome of tuberous Begonia was clearly pronounced in ‘Elatior’-begonias
when the probe concentration was ~3.75 ng/μl (150 ng/slide), with 30 times the excess of B. socotrana blocking DNA and stringency of post hybridization washings at 73% (0.1× SSC at 42°C). In ‘Elatior’-begonias hybrids GISH
distinguished two groups comprising short (0.6–1.03 μm in length) and relatively longer chromosomes (1.87–3.88 μm) which represent
B. socotrana and tuberous Begonia genomes, respectively. The number of chromosomes derived from tuberous Begonia ranged from 14 to 56
and for B. socotrana from 7 to 28 which suggest the presence of different ploidy levels in analyzed ‘Elatior’-begonia hybrids. Intergenomic recombination
has not been detected through GISH in hybrids analyzed. Genomic in situ hybridization turned out to be useful to identify
the genome constitution of ‘Elatior’-begonia hybrids and thus gain an insight into the origins of these cultivars. This knowledge
on the ploidy level and genome composition is essential for further progress in breeding Begonias. 相似文献
18.
Somatic hybridization has been an effective and successful technique for plant improvement. In this paper, embryogenic callus protoplasts of red tangerine (Citrus reticulata Blanco) were electrically fused with mesophyll protoplasts from citrange (C. sinensis × P. trifoliata, a Chinese local strain) in an effort to produce complementary tetraploid citrus rootstocks. Regenerated embryoids grew slowly and were vulnerable to browning. Twelve plants were finally regenerated, rooted and transplanted into a greenhouse. Root‐tip chromosome counting of five randomly‐selected plants revealed most cells were tetraploid (2n = 4x = 36), but aneuploid cells also existed. Flow cytometry analysis further confirmed their tetraploid nature. Nuclear simple sequence repeat (SSR) analysis verified their hybridity. Further mitochondrial genome analysis by restriction fragment length polymorphism and cleaved amplified polymorphic sequence revealed their mtDNA banding pattern was identical to that of red tangerine, the embryogenic callus parent; while their chloroplast DNA inheritance was random as revealed by chloroplast SSR analysis, in addition to cpDNA co‐existence detected in one plant. Cytological and molecular analysis indicated that somatic hybrid plants between red tangerine and citrange had been successfully obtained. 相似文献
19.
Manli Li Nana Yuyama Mariko Hirata Jianguo Han Yunwen Wang Hongwei Cai 《Euphytica》2009,170(3):327-338
A consensus genetic linkage map with 447 SSR markers was constructed for zoysiagrass (Zoysia japonica Steud.), using 86 F1 individuals from the cross ‘Muroran 2’ × ‘Tawarayama Kita 1’. The consensus map identified 22 linkage groups and had a total
length of 2,009.9 cM, with an average map density of 4.8 cM. When compared with a previous AFLP-SSR linkage map, the SSR markers
from each linkage group mapped to similar positions in both maps. Eight pairs of linkage groups from the AFLP-SSR map were
joined into eight new groups in the current map. This zoysiagrass consensus map contained 35 SSR markers exhibiting high homology
with rice genomic sequences from known chromosomal locations. This allowed synteny to be identified between Zoysiagrass linkage
groups 2, 3, 9, 19 and rice chromosomes 3, 12, 2, 7 respectively. These results provide important comparative genomics information
and the new map is now available for quantitative trait locus analysis, marker-assisted selection and breeding for important
traits in zoysiagrass. 相似文献
20.
Summary Central Asian apricot germplasm was used in hybridizations with California adapted apricots to increase Brix levels and improve fresh eating quality. Fruit from parental trees, the F1 hybrid and two backcross families were evaluated for fruit quality traits and analyzed by HPLC for specific sugar content. The F1 hybrid between Central Asian and California adapted apricots was intermediate to its parents in many of the evaluated characteristics and levels of specific sugars. When the F1 hybrid was backcrossed to California adapted apricots ‘Lorna’ and ‘Robada,’ the resulting hybrids were diverse in Brix, juice acidity, fruit size and profiles of specific sugars. Glucose: fructose ratios higher that 3.3 were encountered in fruit from five of the 22 analyzed seedlings, and fructose: sorbitol ratio ranged from 0.67 to 6.46. Brix and total sugar content correlated significantly with each other and with both sucrose and glucose. No significant correlations existed between sorbitol and any of the other analyzed sugars, nor with Brix or total sugars. The results demonstrated the extent of sugar profile modification possible in California adapted apricots after just two generations of breeding with Central Asian apricot germplasm. 相似文献