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1.
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
2.
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
3.
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
4.
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
5.
Chun-Qing Sun Fa-Di Chen Nian-Jun Teng Zhao-Lei Liu Wei-Min Fang Xi-Lin Hou 《Euphytica》2010,171(2):181-192
Reproductive barriers often exist in the crosses between Dendranthema grandiflorum (Ramat.) Kitamura and its wild species and seriously result in low seed set, consequently reducing breeding efficiency. For
the purpose of revealing the factors leading to low seed set, we investigated pollen viability, germination behavior of pollen
grains on stigmas and embryo development in the crosses between D. grandiflorum and three wild species, D. nankingense (Nakai) Tzvel., D. indicum (L.) Des Moul. and D. zawadskii (Herb.) Tzvel. using technique of paraffin section, and light, fluorescence and scanning electron microscopy. The results
indicated pollen viability of three wild species ranged from 20 to 25%. In the cross between D. grandiflorum and D. nankingense, very few pollen grains germinated on stigmas after pollination and most of them germinated abnormally. In addition, normal
embryos were observed in 12% ovaries at 8 days after pollination and thereafter all the embryos aborted. In other two crosses,
many pollen grains germinated on stigmas and pollen tubes penetrated stigmas normally after pollination. Moreover, normal
embryos were observed in over 50% ovaries from 8 to 15 days after pollination in the cross between D. grandiflorum and D. indicum, and seed set was 59%. In the cross between D. grandiflorum and D. zawadskii, normal embryos were observed in 52% ovaries at 8 days after pollination. After that, however, most embryos degenerated and
seed set was only 9%. These data suggest that pollen viability has no significant effects on seed set of the three crosses.
Very few germinated pollen grains on stigmas and abnormal growth of most pollen tubes before fertilization, and embryo abortion
are the main factors causing failure of the cross between D. grandiflorum and D. nankingense, whereas only embryo abortion is a main factor resulting in low seed set in the cross between D. grandiflorum and D. zawadskii and no barriers occur in the cross between D. grandiflorum and D. indicum. 相似文献
6.
The genus Kalanchoe is currently divided into section Kalanchoe and section Bryophyllum, and there has been no successful report on the production
of inter-sectional hybrids. Therefore, reciprocal crosses were made between Kalanchoe spathulata (sect. Kalanchoe) and K. laxiflora (sect. Bryophyllum) in order to obtain basic information on the reproductive barriers between these two sections. The seeds
were aseptically germinated in vitro and the plants were grown in greenhouse till flowering. When K. spathulata was used as a maternal donor, 39 out of 80 plants showed intermediate characteristics between K. spathulata and K. laxiflora. In contrast, no plants were obtained in the reverse crosses. Hybridity of these plants was confirmed by flow cytometric
analysis, chromosome numbers and RAPD analysis. Bulbil formation on the leaf margin as one of the conspicuous characteristics
of K. laxiflora was not observed in the hybrids. Some of the hybrid lines showed some pollen fertility, but failed to yield viable seeds
by self-pollination or backcross-pollination. Successful production of the inter-sectional hybrid between the two species
suggests that they are not so distantly related as considered previously. 相似文献
7.
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
8.
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
9.
Drought and low soil fertility are considered the most important abiotic stresses limiting maize production in sub-Saharan
Africa. Knowledge of the combining ability and diversity of inbred lines with tolerance to the two stresses and for those
used as testers would be beneficial in setting breeding strategies for stress and nonstress environments. We used 15 tropical
maize inbred lines to (i) evaluate the combining ability for grain yield (GY), (ii) assess the genetic diversity of this set
of inbred lines using RFLP, SSR, and AFLP markers, (iii) estimate heterosis and assess the relationship between F1 hybrid performance, genetic diversity and heterosis, and (iv) assess genotype × environment interaction of inbred lines and
their hybrids. The F1 diallel hybrids and parental inbreds were evaluated under drought stress, low N stress, and well-watered conditions at six
locations in three countries. General combining ability (GCA) effects were highly significant (P < 0.01) for GY across stresses and well-watered environments. Inbred lines CML258, CML339, CML341, and CML343 had the best
GCA effects for GY across environments. Additive genetic effects were more important for GY under drought stress and well-watered
conditions but not under low N stress, suggesting different gene action in control of GY. Clustering based on genetic distance
(GD) calculated using combined marker data grouped lines according to pedigree. Positive correlation was found between midparent
heterosis (MPH) and specific combining ability (SCA), GD and GY. Hybrid breeding program targeting stress environments would
benefit from the accumulation of favorable alleles for drought tolerance in both parental lines. 相似文献
10.
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
11.
Interspecific hybridization is an important approach to broaden the genetic base and create novel plant forms in breeding
programs. However, interspecific hybridization in Ipomoea is very difficult due to the cross incompatibility. Here we report two novel interspecific F1 hybrids between I. batatas (L.) Lam. (2n = 6x = 90) and two wild species, I. grandifolia (2n = 2x = 30) and I. purpurea (2n = 2x = 30). Hybridization was stimulated by applying plant growth hormones. Morphological, molecular and cytological tests were
conducted to confirm their hybridity. We found that the two hybrids were quite distinctive in leaf color and morphology, and
yielded intermediate sizes of storage roots compared to their respective parents. Inter-simple sequence repeat analysis showed
that the unique DNA bands from the wild parents could be detected in these two hybrids. The cluster analysis also showed that
the two F1 hybrids were closer to I. batatas in phylogeny relationship. The number of chromosomes of the two hybrids was both 60, indicating that the hybrids were tetraploid.
The meiotic configuration analysis of the H1 of I. batatas × I. grandifolia revealed the occurrence of 17.58I + 14.28II + 1.36III + 2.48IV at metaphase I in average chromosome association per pollen
mother cells (PMCs), 4.26I + 18.32II + 2.56III + 3.12IV was average meiotic configuration in the H2 of I. batatas × I. purpurea. Both hybrids appeared to be polyads and multi-microcytes at tetrad phase and differed in their pollen fertility. 相似文献
12.
Hadi Pirasteh Anosheh Hossein Sadeghi Yahya Emam 《Journal of Crop Science and Biotechnology》2011,14(4):289-295
Seed priming is a method to improve germination and seedling establishment under stress conditions. The effect of seed priming
in chemical solutions such as urea and KNO3, on protein and proline content, germination, and seedling growth responses of four maize (Zea mays L.) hybrids under drought and salt stress conditions was studied in a controlled environment in 2010. Treatments included
stress type and intensity at five levels: moderate drought (MD), severe drought (SD), moderate salt (MS), severe salt (SS),
and control (C1, without stress), three seed priming types including water (C2, as control), KNO3, and urea (as chemical priming), and four maize hybrids including Maxima, SC704, Zola, and 307. The results showed that the
highest germination percentage (Ger %), germination rate (GR), seedling length (SL), radical length (RL), and seedling to
radical length ratio (S/R) were achieved in no stress treatments and most proline content in SD treatment. Urea priming led
to more Ger%, GR, and SL compared to other primers and treatment under KNO3 priming resulted in higher RL compared to other primers. Chemical priming had no effect on S/R and proline content. Also,
in terms of most traits, no difference was found among the four hybrids. Results showed that salt stress could affect GR and
RL more than the drought stress. Drought stress affected germination percentage and S/R more than the salt stress. Both stresses
decreased all measured parameters, except protein and proline content which were increased remarkably, and more under drought
compared to salt stress. Based on proline content, hybrid 304 appeared to be more resistant to stress than other hybrids.
Generally, KNO3 and urea alleviated effects of both stresses and led to increased germination and seedling growth as well as the root length.
Therefore, priming could be recommended for enhancing maize growth responses under stressful conditions. 相似文献
13.
Using three varieties of Brassica rapa, cv. Hauarad (accession 708), cv. Maoshan-3 (714) and cv. Youbai (715), as the maternal plants and one variety of B. oleracea cv. Jingfeng-1 (6012) as the paternal plant, crosses were made to produce interspecific hybrids through ovary culture techniques. A better response of seed formation was observed when ovaries were cultured in vitro at 9–12 days after pollination on the basal MS and B5 media supplemented with 6-benzylaminopurine (BA) and naphthylacetic acid (NAA). The best response was observed for cross 714×6012 with the rate of seeds per ovary reaching 43.0%. Seeds for cross 715×6012 showed the best germination response (66.7%) on the regeneration medium (MS+1.0 mg l–1 BA+0.05 mg l–1 NAA). In all three cross combinations, good response in terms of root number and length of plants was observed on the root induction medium (MS+1.0 mg l–1 BA+0.1 mg l–1 NAA). A better response was observed for the regenerated plants cultured for 14 days than for 7 days. The ovary-derived plants with well-developed root system were hardened for 8 days and their survival rate reached over 80%. Cytological studies showed that the chromosome number of all plants tested was 19 (the sum of both parents), indicating that these regenerated plants were all true hybrids of B. rapa (n = 10) × B. oleracea (n = 9). The regenerated plants were doubled with colchicine treatment, and the best response in the crosses 708×6012, 714×6012 and 715×6012 was observed when treated with 170 mg l–1 colchicine for up to 30 h and their doubling frequency reached 52, 56 and 62%, respectively. 相似文献
14.
Dragan Milić Slobodan Katić Đura Karagić Jelica Gvozdanović–Varga Sofija Petrović Jan Boćanski 《Euphytica》2011,182(1):25-33
The objective of this study was to develop diallel population hybrids by crossing selected germplasm and to determine the
gene effects and genetic control of yield and yield components using diallel analysis. A complete diallel including reciprocals
was made during 2003 and 2004 between five alfalfa cultivars of different geographic origin. For each pairwise cross, five
plants were chosen at random from each of the two cultivars (~100 florets per plant) to obtain the F1 generation. A spaced plant field was established in 2006 which included the five alfalfa cultivars (parents) and their 20
diallel hybrids (F1). The results of the diallel analysis suggest that the genetic control of major agronomic traits is determined by both additive
gene action (accumulation of frequency of desirable alleles represented by significant GCA effects) and nonadditive gene action
(complementary gene interactions represented by significant SCA effects). This type of gene action expression in alfalfa also
determines the way in which breeding is carried out and brings about changes in the methods used and has given rise to the
idea of the semi-hybrid breeding of this crop. The concept involves: breeding alfalfas within the population, identification
of heterotic germplasm, and the production of seed of the population hybrid (PH). 相似文献
15.
Gabriela de Oliveira Belo Margarete Magalhães Souza Gonçalo Santos Silva Manuella Palmeira Lavinscky 《Euphytica》2018,214(1):2
Two new varieties of interspecific hybrids of Passiflora have been developed from the cross between P. gardneri versus P. gibertii, both registered under the Passiflora Society International. Twelve putative hybrids were analyzed. Hybridization was confirmed using RAPD and SSR markers. Primer UBC11 (5′-CCGGCCTTAC-3′) generated informative bands. Primer SSR Pe75 has amplified species-specific fragments and a heterozygote status was observed with two parent bands 300 and 350 bp. The molecular markers generated have been analyzed for the presence or absence of specific informative bands. Based on the morphological characterization, we have identified two hybrid varieties: P. ‘Gabriela’ and P. ‘Bella’. P. ‘Gabriela’ produced flowers in bluish tones, bluish petals on the adaxial and abaxial faces, light blue sepals on the adaxial and light green on the abaxial faces, corona with the base of filaments in intense lilac color and white apex. P. ‘Bella’ produced flowers in lilac tones, intense lilac petals on the adaxial and abaxial faces, dark lilac sepals with whitish edges on the adaxial and light green on the abaxial faces, corona with the base of filaments in intense lilac color and white apex. The cytogenetic analysis verified that the hybrids have the same chromosomal number as the parents (2n = 18); the formation of bivalents between the homeologous chromosomes (n = 9) was observad, leading to regular meiosis, which allows the sexual reproduction and use of these hybrids in breeding programs. 相似文献
16.
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
17.
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
18.
Junghyun Shim Olivier Panaud Clémentine Vitte Merlyn S. Mendioro Darshan S. Brar 《Euphytica》2010,176(2):269-279
Molecular markers have been successfully used in rice breeding however available markers based on Oryza
sativa sequences are not efficient to monitor alien introgression from distant genomes of Oryza. We developed O. minuta (2n = 48, BBCC)-specific clones comprising of 105 clones (266–715 bp) from the initial library composed of 1,920 clones against
O. sativa by representational difference analysis (RDA), a subtractive cloning method and validated through Southern blot hybridization.
Chromosomal location of O. minuta-specific clones was identified by hybridization with the genomic DNA of eight monosomic alien additional lines (MAALs). The
37 clones were located either on chromosomes 6, 7, or 12. Different hybridization patterns between O. minuta-specific clones and wild species such as O. punctata, O. officinalis, O. rhizomatis, O. australiensis, and O. ridleyi were observed indicating conservation of the O. minuta fragments across Oryza spp. A highly repetitive clone, OmSC45 hybridized with O. minuta and O. australiensis (EE), and was found in 6,500 and 9,000 copies, respectively, suggesting an independent and exponential amplification of the
fragment in both species during the evolution of Oryza. Hybridization of 105 O. minuta specific clones with BB- and CC-genome wild Oryza species resulted in the identification of 4 BB-genome-specific and 14 CC-genome-specific clones. OmSC45 was identified as a fragment of RIRE1, an LTR-retrotransposon. Furthermore this clone was introgressed from O. minuta into the advanced breeding lines of O. sativa. 相似文献
19.
Amaresh Chandra 《Euphytica》2009,169(3):363-374
The genus Medicago encompasses many important forage species for both temperate and tropical regions. M. sativa L., commonly known as lucerne, is one of the most important forage species grown worldwide, but its production suffers seriously
from weevil (Hypera postica Gyll.) infestation. The aim of this work was to identify species/accessions with tolerance to weevil and their molecular
analysis using simple sequence repeat (SSR) markers. After screening 197 global germplasm encompassing 50 Medicago species for weevil tolerance, 22 lines representing 13 species were identified where leaf damage was ≤15% (P ≤ 0.05). In total, 37 accessions of the 22 lines, five Indian lucerne cultivars with leaf damage ≥75% and 10 accessions of
the 13 Medicago species with low to high infestation (>25%) were molecularly assessed using 11 SSR markers (5 newly developed) to delineate
closest to lucerne lines for breeding. In total, 33 bands were scored. The SAHN clustering using UPGM algorithm resulted into
two main clusters supported with high boot strap values and with genetic similarity ranging from 0.33 to 0.96. Two accessions
of M. tenoreana were observed closest to Indian lucerne cultivars. The rich variability revealed can be used as potential resource for transferring
genes across species. Although the inter-specific hybridization is difficult preposition in genus Medicago largely due to post fertilization barrier, the identified species/accessions can be utilized on priority in breeding programs
especially employing biotechnological tools like culturing of fertilized pods, ovule-embryo culture and electroporation. 相似文献
20.
Honggen Zhang Xiaojun Cheng Lijia Zhang Hua Si Yongshen Ge Minghong Gu Shuzhu Tang 《Euphytica》2018,214(3):49
Wild abortive (WA)-type cytoplasmic male sterility (CMS) has been exclusively used for breeding three-line hybrid indica rice, but it has not been applied for generating japonica hybrids because of the difficulties related to breeding japonica restorer lines. Determining whether the major restorer-of-fertility (Rf) gene used for indica hybrids can efficiently restore the fertility of WA-type japonica CMS lines may be useful for breeding WA-type japonica restorer lines. In this study, japonica restorer lines for Chinsurah Boro II (BT)-type CMS exhibited varying abilities to restore the fertility of ‘WA-LiuqianxinA’, which is a WA-type japonica CMS line. Additionally, Rf genes for WA-type CMS were identified in the BT-type japonica restorers. Meanwhile, ‘C9083’, which is a BT-type japonica restorer, exhibited a limited ability to restore the fertility of WA-type japonica CMS lines, and a genetic analysis revealed that the fertility restoration was controlled by one locus. The Rf gene was mapped to an approximately 370-kb physical region and was identified as Rf4. Furthermore, Rf gene dosage effects and the temperature influenced the fertility restoration of WA-type japonica CMS lines. This study is the first to confirm that Rf4 has only minor effects on the fertility restoration of WA-type japonica CMS lines. These results may be relevant for the development of WA-type japonica hybrids. 相似文献