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1.
Chun-Qing Sun Fa-Di Chen Nian-Jun Teng Zhao-Lei Liu Wei-Min Fang Xi-Lin Hou 《Euphytica》2010,174(1):51-60
Chrysanthemum grandiflorum ‘Yuhuaxingchen’ is an important commercial chrysanthemum cultivar with excellent ornamental quality but low drought tolerance,
whereas C. indicum has exceptional drought tolerance. In our earlier study, many hybrid seeds between them were obtained through interspecific
hybridization. In the present study, we selected six putative hybrid lines with most drought tolerance from all the hybrid
lines by withholding water, indentified their facticity by chromosome counting, and then evaluated their drought tolerance
through determining foliar electrolyte leakage (EL), contents of malondialdehyde (MDA) and proline, and plant survival rate
after 20% polyethylene glycol 6000 treatment. It was found that 155 out of 282 seeds germinated and only 132 seedlings survived.
In addition, chromosome and morphological analysis showed that the six putative hybrids were real hybrids and their morphological
features were intermediate between their parents. Furthermore, the density of leaf epidermal hair, proline content, and plant
survival rate were the highest in C. indicum and the lowest in C. grandiflorum among the six hybrids and their parents. In contrast, EL value and MDA content were the highest in C. grandiflorum and the lowest in C. indicum. These results suggest that some true hybrids with improved drought tolerance can be obtained through interspecific hybridization
in chrysanthemum breeding. Therefore, interspecific hybridization between chrysanthemum cultivars and their wild species may
become a promising way to improve their biotic and abiotic resistance in the future breeding. 相似文献
2.
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
3.
Ovary rescue was employed to create six interspecific hybrids from the cross between Dendranthema morifolium (Ramat.) Kitamura ‘rm20-12’ (2n = 54) and its wild diploid relative D. nankingense (Nakai) Tzvel. (2n = 18). The morphology of the hybrids differed from that of either parent. The leaf length and width of all three D. morifolium × D. nankingense hybrids exceeded that of the parents, as did the plant height of two and the inflorescence diameter of another of the hybrids.
One of the reciprocal hybrids was heterotic for leaf length and width. All the hybrids bore yellow flowers. The cold tolerance
of five hybrids was significantly superior to that of their D. morifolium parent. Interspecific hybridization clearly provides an effective means of cultivar improvement in chrysanthemum. 相似文献
4.
Zea mays ssp. mexicana, an annual wild relative of maize, has many desirable characteristics for maize improvement. To transfer alien genetic germplasm
into maize background, F1 hybrids were generated by using Z. mays ssp. mexicana as the female parent and cultivated maize inbred line Ye515 as the male parent. Alien introgression lines, with a large range
of genetic diversity, were produced by backcross and successive self-pollinations. A number of alien introgression lines with
the predominant traits of cultivated maize were selected. Genomic in situ hybridization (GISH) proved that small chromosome
segments of Z. mays ssp. mexicana had been integrated into the maize genome. Some outstanding alien introgression lines were evaluated in performance trials
which showed 54.6% hybrids had grain yield greater than that of hybrid check Yedan12 which possessed 50% Ye515 parentage,
and 17.1, 9.9% hybrids had grain yield competitive or greater than those of Nongda108 and Zheng958, which were elite commercial
hybrids in China, respectively. The results indicated that some of the introgression lines had excellent agronomic traits
and combining ability for maize cultivar, and demonstrated that Z. mays ssp. mexicana was a valuable source for maize breeding, and could be used to broaden and enrich the maize germplasm. 相似文献
5.
P. Kaushal Aarti Khare S. A. Siddiqui A. Agrawal Sharmishtha Paul D. R. Malaviya A. K. Roy S. N. Zadoo 《Euphytica》2010,174(2):261-281
New tri-species hybrids (GOS) in the genus Pennisetum involving the cultivated species pearl millet (P. glaucum L.) and two wild species, viz. P. squamulatum Fresen and P. orientale L. C. Rich, are reported. Six hybrid plants were recovered after crossing a backcross hybrid (2n = 3x = 23, GGO) between P. glaucum (2n = 2x = 14, GG) and P. orientale (2n = 2x = 18, OO) with F1s (2n = 6x = 42, GGSSSS) between P. glaucum (2n = 4x = 28, GGGG) and P. squamulatum (2n = 8x = 56, SSSSSSSS). The hybrids were perennial, morphologically intermediate to their parents, and represented characters from the three contributing
species. The hybrids contained 2n = 44 chromosomes (GGGSSO) representing 21, 14 and nine chromosomes from P. glaucum, P. squamulatum and P. orientale, respectively. Meiotic and flow-cytometric analysis suggested origin of these hybrids from unreduced female and reduced male
gametes. Average chromosome configuration (8.42I + 14.32II + 1.62III + 0.52IV) at Meiosis showed limited inter-genomic pairing indicating absence of significant homology between the three genomes. The
hybrids were male sterile (except one) and highly aposporous. P. orientale was identified to induce apospory in hybrid background with P. glaucum at diploid and above levels, though it was quantitatively affected by genomic doses from sexual parent. A case of inducible
and recurrent apospory is presented whereby a transition from Polygonum-type sexual embryo-sacs to Panicum-type aposporous
embryo-sacs was observed in diploid interspecific hybrids. Results supported independent origin and partitioning of the three
apomixis-components (apomeiosis, parthenogenesis, and functional endosperm development), reported for the first time in Pennisetum. Potential utilization of GOS hybrids in understanding genome interactions involved in complex traits, such as perenniality
and apomixis, is discussed. 相似文献
6.
Katrijn Van Laere Leen Leus Johan Van Huylenbroeck Erik Van Bockstaele 《Euphytica》2009,166(3):445-456
Interspecific hybrids Buddleja
davidii × Buddleja
weyeriana, Buddleja
weyeriana × Buddleja
davidii and Buddleja
davidii × Buddleja
lindleyana were generated using in vitro embryo rescue 10–11 weeks after manual pollination. The morphological variation within the
F1 populations was limited. The F1 progeny of B. davidii × B. lindleyana was almost sterile and no F2 generation was obtained. From the other hybrids, F2 generations were made by self pollinations
and back crosses. Hybrid nature of all F1 and F2 seedlings was confirmed by AFLP. Chromosome counting and genome size measurement
for B. weyeriana (F2 selection of (diploid) B. globosa × (tetraploid) B. davidii) revealed a higher chromosome number (76 chromosomes) and genome size than expected, indicating 2n-gametes formation occurred during meiosis of B. globosa. The F1 hybrids B. weyeriana × B. davidii (76 chromosomes) had an intermediate genome size compared with the genome size of the parent plants, proving their hybrid
nature. However, the F1 and F2 hybrids of B. davidii × B. weyeriana all had 76 chromosomes but had a lower genome size than expected, suggesting the occurrence of chromosome rearrangements
in the genome of the hybrids. B. lindleyana had 38 chromosomes, while the F1 hybrids of B. davidii × B. lindleyana had 76 chromosomes. Also genome size measurements revealed that the F1 seedlings B. davidii × B. lindleyana had higher genome sizes than expected. Both the results of chromosome counting and genome size measurement indicate that
2n-gametes formation took place during meiosis of B. lindleyana. 相似文献
7.
Aneeta Pradhan Julie A. Plummer Matthew N. Nelson Wallace A. Cowling Guijun Yan 《Euphytica》2010,176(1):87-98
A triploid hybrid with an ABC genome constitution, produced from an interspecific cross between Brassica napus (AACC genome) and B. nigra (BB genome), was used as source material for chromosome doubling. Two approaches were undertaken for the production of hexaploids:
firstly, by self-pollination and open-pollination of the triploid hybrid; and secondly, by application of colchicine to axillary
meristems of triploid plants. Sixteen seeds were harvested from triploid plants and two seedlings were confirmed to be hexaploids
with 54 chromosomes. Pollen viability increased from 13% in triploids to a maximum of 49% in hexaploids. Petal length increased
from 1.3 cm (triploid) to 1.9 cm and 1.8 cm in the two hexaploids and longest stamen length increased from 0.9 cm (triploid)
to 1.1 cm in the hexaploids. Pollen grains were longer in hexaploids (43.7 and 46.3 μm) compared to the triploid (25.4 μm).
A few aneuploid offsprings were also observed, with chromosome number ranging from 34 to 48. This study shows that trigenomic
hexaploids can be produced in Brassica through interspecific hybridisation of B. napus and B. nigra followed by colchicine treatment. 相似文献
8.
The present study aims at characterization of Jatropha species occurring in India using nuclear and organelle specific primers for supporting interspecific gene transfer. DNA from
34 accessions comprising eight agronomically important species (Jatropha curcas, J. gossypifolia, J. glandulifera, J. integerrima, J. podagrica, J. multifida, J. villosa, J. villosa. var. ramnadensis, J. maheshwarii) and a natural hybrid, J. tanjorensis were subjected to molecular analysis using 200 RAPD, 100 ISSR and 50 organelle specific microsatellite primers from other
angiosperms. The nuclear marker systems revealed high interspecific genetic variation (98.5% polymorphism) corroborating with
the morphological differentiation of the species used in the study. Ten organelle specific microsatellite primers resulted
in single, discrete bands of which three were functional disclosing polymorphism among Jatropha species. The PCR products obtained with organelle specific primers were subjected to sequence analysis. PCR products from
two consensus chloroplast microsatellite primer pairs (ccmp6 and 10) revealed variable number of T and A residues in the intergenic
regions of ORF 77–ORF 82 and rp12–rps19 regions, respectively in Jatropha. Artificial hybrids were produced between J. curcas and all Jatropha species used in the study with the exception of J. podagrica. Characterization of F1 hybrids using polymorphic primers specific to the respective parental species confirmed the hybridity of the interspecific
hybrids. Characterization of both natural and artificially produced hybrids using chloroplast specific markers revealed maternal
inheritance of the markers. While the RAPD and ISSR markers confirmed J. tanjorensis as a natural hybrid between J. gossypifolia and J. curcas, the ccmp primers (ccmp6 and 10) unequivocally established J. gossypifolia as the maternal parent. Evaluation of backcross interspecific derivatives of cross involving J. curcas and J. integerrima indicate scope for prebreeding and genetic enhancement of Jatropha curcas through interspecific hybridization. 相似文献
9.
Nicotiana wuttkei Clarkson and Symon discovered in the 1990s in Australia may be of potential interest to breeders as it carries resistance
to Peronospora hyoscyami de Bary. The crossability between N. wuttkei (2n = 4x = 32) and three N. tabacum (2n = 4x = 48) cultivars (‘Puławski 66’, ‘Wiślica’ and ‘TN 90’) and the morphology and cytology of their amphihaploid hybrids (2n = 4x = 40) were studied. Seeds were produced only when N. wuttkei was used as the maternal parent, but under normal germination all seedlings died. Viable F1 hybrids of N. wuttkei × N. tabacum cv. ‘Puławski’ and N. wuttkei × N. tabacum cv. ‘Wiślica’ were obtained only by in vitro cotyledon culture. The amphihaploid plants were intermediate between the parents
for most morphological traits. In 46.4% of the PMC’s, only univalents were present. The remainder of the cells had 1–5 bivalents
and 1–2 trivalents. In spite of a detectable frequency of monads (2.6%), dyads (2.6%) and triads (4.5%), the hybrids were
self and cross sterile. 相似文献
10.
Takahiro Iizuka Tsutomu Kuboyama Wataru Marubashi Masayuki Oda Takahiro Tezuka 《Euphytica》2012,186(2):321-328
To elucidate the genetic mechanism of hybrid lethality observed in hybrids between cultivated tobacco, Nicotiana tabacum, and wild tobacco species in the section Suaveolentes, genetic analyses were conducted through the triple cross of the hybrids of wild species, including N. benthamiana and N. fragrans, and N. tabacum. N. benthamiana and N. fragrans produced only viable hybrids after crossing with N. tabacum. Subsequently, N. benthamiana and N. fragrans were crossed with N. africana, N. debneyi, and/or N. suaveolens, which produced inviable hybrids after crossing with N. tabacum. Hybrids of the wild species were obtained from four of the six cross combinations. Only when hybrid plants of N. debneyi × N. fragrans, whose hybridity was confirmed by morphological characteristics, random amplified polymorphic DNA analysis, and chromosome observation, were crossed with N. tabacum, triple hybrids were obtained and segregated 1:1 (lethal:viable). Based on these results, a single dominant gene, designated Hybrid Lethality A1 (HLA1), in N. debneyi was found to control hybrid lethality by the interaction with gene(s) on the Q chromosome in N. tabacum. This represents the first report to identify a causal gene for hybrid lethality in the genus Nicotiana. 相似文献
11.
Renanthera imschootiana and Vanda coerulea are two rare and endangered orchid species featuring in IUCN Red List of Threatened Plants as well as in Red Data Book of
Indian Plants, and are renowned for their unique ornamental traits. Renanthera imschootiana and V. coerulea have different flowering periods and by taking opportunity of off-season flowering of V. coerulea which happened during the flowering season of R. imschootiana, the hybridization was effected by hand-pollination. Viable pollinia were present in the off-season flowers of V. coerulea and one out of four cross was successful when R. imschootiana was taken as female parent. Reciprocal cross was unsuccessful. The resulting immature hybrid embryos were germinated in vitro
on Vacin and Went medium supplemented with 15% v/v coconut water. Best seedling growth was observed on half-strength Murashige
and Skoog medium devoid of any plant growth regulators while the transplanted seedlings grew best on brick chips:charcoal
pieces (2:1) potting mix in community earthen trays. First flowering of the hybrid seedlings happened four years ten months
after transfer to ex vitro environment. RAPD markers generated by the decamer primer OPA1 convincingly confirmed the hybridity.
Registration of the hybrid was made with the Royal Horticultural Society with the grex Renantanda Kebisana Shija. 相似文献
12.
Psathyrostachys huashanica Keng ex Kuo (2n = 2x = 14, NsNs), a source of wheat stripe rust, take-all fungus, and powdery mildew resistance with tolerance to salinity and drought, has been successfully hybridized as the
pollen parent to bread wheat without using immature embryo rescuing culture for the first time. All of the CSph2b × P. huashanica hybrid seeds germinate well. Backcross derivatives were successfully obtained. F1 hybrids were verified as intergeneric hybrids on the basis of morphological observation, cytological and molecular analyses.
The results obviously showed the phenotypes of the hybrid plants were intermediate between bread wheat and P. huashanica. Chromosome pairing at MI of PMCs in the F1 hybrid plants was low, and the meiotic configuration was 26.80 I + 0.60 II (rod). Cytological analysis of the hybrid plants
revealed the ineffectiveness of the ph2b gene on chromosome association between the parents. Eight RAPD-specific markers for Ns genome were selected for RAPD analysis, and the results indicated that F1 hybrids contained the Ns genome of P. huashanica. Furthermore, the significance of the finding for bread wheat improvement was discussed. 相似文献
13.
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
14.
The present study evaluated the individual plants reaction of F2 hybrid generation of C. annuum: ATZ1 × PO and ATZ1 × CDT as well as two interspecific hybrids: C. frutescens × C. annuum ATM1 and C. frutescens × C. chinense on androgenesis conditions in in vitro anther cultures. The experiment was carried out following a modified method of Dumas
de Vaulx et al. (Agronomie 1:859–864, 1981). There were demonstrated clear differences in the effectiveness of androgenesis
both between the pepper hybrid forms as well as among individual plants of all the genotypes tested. The highest effectiveness
of androgenic embryos development was observed for the cultivated form of C. annuum: (ATZ1 × PO)F2. Anthers of most of the plants of this hybrid produced embryos at the level higher than 5%, while in anther cultures of the
second C. annuum hybrid (ATZ1 × CDT)F2 almost 3-fold fewer embryos and plants were produced. Anthers isolated from flower buds of interspecific hybrids formed much
lower number of embryos. A positive reaction was recorded for five hybrid plants of (C. frutescens × C. annuum ATM1)F2, while in case of (C. frutescens × C. chinense)F2 androgenic embryos were obtained from anthers of two plants. Only in the case of a one of these plants did the effectiveness
of androgenesis exceed 5%. The ploidy level of the regenerants was determined by flow cytometry. Among the regenerants there
were observed both haploid forms and the plants with the diploid number of chromosomes. 相似文献
15.
Nadeem Khan Rodrigo Barba-Gonzalez M. S. Ramanna Paul Arens Richard G. F. Visser Jaap M. Van Tuyl 《Euphytica》2010,171(2):157-173
Sexual polyploids were induced in diploid (2n = 2x = 24) interspecific F1 hybrids of Longiflorum × Asiatic (LA) and Oriental × Asiatic (OA) Lilium hybrids by backcrossing to Asiatic (AA) parents as well as by sib-mating of the F1 LA hybrids. A majority of the BC1 progenies
were triploid and the progenies from sib-mating were tetraploid or near tetraploids. Genomic in situ hybridization (GISH)
technique was applied to assess the intergenomic recombination in the BC1 populations of LA and OA hybrids obtained after
unilateral sexual polyploidization. A total of 63 LA (LA × AA and AA × LA) and 53 OA hybrids were analysed. LA hybrids were
originated through the functioning of 2n gametes either as 2n eggs or 2n pollen while those of OA hybrids originated through functional 2n pollen of diploid OA genotype. In both type of crosses, a majority of the progenies had originated through First Division
Restitution (FDR) mechanism of functional 2n gamete either with or without a cross over. However, there were nine LA- and four OA-genotypes where Indeterminate Meiotic
Restitution (IMR) was the mechanism of 2n gamete formation. Based on GISH, total amount of introgression of Longiflorum and Oriental genome into Asiatic genome was
determined. Most of the BC progenies exhibited recombination and the amount of recombination was higher in LA hybrids as compared
to OA hybrids. Intergenomic recombination was also determined cytologically in the 16 plants of sib-mated LA hybrids where
both parents had contributed 2n gametes. Based on these results the nature of interspecific lily hybrids obtained from uni- and bilateral sexual polyploidization
leading to allotriploid and allotetraploid formation is discussed in the context of introgression and intergenomic recombination. 相似文献
16.
Cytoplasmic-nuclear male-sterility is an important biological tool, which has been used by plant breeders to increase yields
in cross-pollinated cereals and vegetables by commercial exploitation of the phenomenon of hybrid vigor. In legumes, no such
example exists due to the absence of an economic way of mass pollen transfer from male to female parent. Pigeonpea [Cajanus cajan (L.) Millsp.], however, is a different legume where a moderate level of insect-aided natural out-crossing (25–70%) exists
and it can be used to produce commercial hybrid cultivars, if an efficient and stable cytoplasmic-nuclear male-sterility (CMS)
system is available. This paper reports the development of a stable CMS system (ICP 2039A), derived from an inter-specific
hybrid of Cajanus cajanifolius, a wild relative of pigeonpea, with a cultivar ICP 11501. Using this genetic material, designated as the A4 cytoplasm, a number of fertility restorers and maintainers have been developed. The best short-duration experimental pigeonpea
hybrid ICPH 2470 produced 3205 kg ha−1 grain yield in 125 days, exhibiting 77.5% advantage over the control cultivar UPAS 120. At present, all the important biological
systems necessary for a successful commercial hybrid breeding program are available in pigeonpea and the package of this technology
has been adopted by private seed sector in India for the production and marketing of hybrid varieties. 相似文献
17.
In a previously made cross Brassica napus cv. Oro (2n = 38) × Capsella bursa-pastoris (2n = 4x = 32), one F1 hybrid with 2n = 38 was totally male sterile. The hybrid contained no complete chromosomes from C. bursa-pastoris, but some specific AFLP (amplified fragment length polymorphism) bands of C. bursa-pastoris were detected. The hybrid was morphologically quite similar to ‘Oro’ except for smaller flowers with rudimentary stamens
but normal pistils, and showed good seed-set after pollination by ‘Oro’ and other B. napus cultivars. The fertility segregation ratios (3:1, 1:1) in its progenies indicated that the male sterility was controlled
by a single recessive gene. In the pollen mother cells of the male sterile hybrid, chromosome pairing and segregation were
normal. Histological sectioning of its anthers showed that the tapetum was multiple layers and was hypertrophic from the stage
of sporogenic cells, and that the tetrads were compressed by the vacuolated and disaggregated tapetum and no mature pollen
grains were formed in anther sacs, thus resulting in male sterility. The possible mechanisms for the production of the male
sterile hybrid and its potential in breeding are discussed. 相似文献
18.
Three CMS lines, Ogu1A, Ogu2A and Ogu3A were selected among ten lines after BC7 based on superior commercial, floral and seed setting traits. Introgression of sterile Ogura cytoplasm in cauliflower nuclear
background reduced the flower size but did not affect commercial and seed setting traits drastically. Line × Tester analysis
was done by taking these three CMS lines free from floral deformities as female parent with nine diverse lines of snowball
cauliflower as tester. The parent Ogu2A exhibited highest GCA effect for curd yield (4.51) and harvest index (1.97) while
Ogu1A exhibited highest GCA for earliness (−2.73). The parent, Ogu2A exhibited significant GCA for curd length (0.39) while,
none of the CMS lines showed significant GCA for curd diameter and depth. Heterosis for curd yield was highest in the hybrid,
Ogu2A × Kt-22 (63.5%) followed by Ogu1A × WF (36.9%) and Ogu1A × Kt-15 was the best hybrid for earliness followed by Ogu3A × Kt-22
with heterosis of −14.4% and −11.7%. However, the number of heterotic hybrids for yield and earliness was low indicating narrow
genetic base of the snowball cauliflower. 相似文献
19.
The recessive mutation of the XANTHA gene (XNT) transforms seedlings and plants into a yellow color, visually distinguishable from normal (green) rice. Thus, it has been
introduced into male sterile lines as a distinct marker for rapidly testing and efficiently increasing varietal purity in
seed and paddy production of hybrid rice. To identify closely linked markers and eventually isolate the XNT gene, two mapping populations were developed by crossing the xantha mutant line Huangyu B (indica) with two wild type japonica varieties; a total of 1,720 mutant type F2 individuals were analyzed for fine mapping using polymorphic InDel markers and high dense microsatellite markers. The XNT gene was mapped on chromosome 11, within in a fragment of ~100 kb, where 13 genes are annotated. The NP_001067671.1 gene
within the delimited region is likely to be a candidate XNT gene, since it encodes ATP-dependent chloroplast protease ATP-binding subunit clp A. However, no sequence differences were
observed between the mutant and its parent. Bioinformatics analysis demonstrated that four chlorophyll deficient mutations
that were previously mapped on the same chromosome are located outside the XNT region, indicating XNT is a new gene. The results provide useful DNA markers not only for marker assisted selection of the xantha trait but also its eventual cloning. 相似文献
20.
Taing Aung Pamela Zwer Robert Park Philip Davies Parminder Sidhu Ian Dundas 《Euphytica》2010,174(2):189-198
Two diploid accessions of wild oat, CIav6956 and CIav7233, were identified as carrying seedling resistance to oat crown rust
(caused by Puccinia coronata f. sp. avenae; Pca). Two vigorous interploidy F1 hybrids were generated from crosses involving the hexaploid oat cultivar Wintaroo and the diploid oat Avena strigosa Schreb. accession CIav6956. An additional interploidy F1 hybrid, designated “F1-Aa1”, was produced from a cross of Wintaroo and the diploid oat accession CIav7233. All three hybrids
were more vigorous and taller than the cultivated parent Wintaroo. The three F1 hybrids contained full chromosome complements from both parents (2n = 4x = 28), but no seeds were obtained when the three F1 hybrids were selfed. Meiotic analyses of the hybrids indicated that they exhibited a high degree of inter-genome and intra-genome
pairing. Trivalent configurations were detected in 95–96% of meiotic cells and a minimum of three bivalents was present in
all cells. An average chiasma frequency of 7.2–7.9 per cell was observed for the three F1 hybrids. A fourth F1 hybrid was subsequently generated from a cross between the diploid oat accession CIav7233 and Wintaroo. One octaploid (2n = 8x = 56) was generated from this hybrid and progeny were resistant to two Pca races. The chromosome number of the octaploid progeny varied between 51 and 54 chromosomes. Development of a chromosome addition
line(s) with the crown rust resistance should be possible from these partial-octaploids. 相似文献