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1.
Pedro M. R. Mendes Moreira Silas E. Pêgo Carlota Vaz Patto Arnel R. Hallauer 《Euphytica》2008,163(3):481-499
In 1984, Pêgo started, with the CIMMYT support, an on-farm participatory maize breeding (PMB) project at the Portuguese Sousa
Valley region (VASO). VASO was intended to answer the needs of small farmers (e.g., yield, bread making quality, ability for
polycropping systems). During 20 years of PMB at VASO, mass (MS) and S2 recurrent selection (S2RS) were applied on the maize
landrace ‘Pigarro’. Morphological (e.g., ear length and fasciation level) and yield evaluations were conducted in Portugal
(2–3 locations in 2 years) and in USA (4 locations in one year) using samples from original population, six MS cycles and three S2RS cycles. North American Populations (BS21, BS22, TEPR-EC6) were also included as checks. ANOVA comparisons
and regression analyses on the rate of direct response to selection were performed. Response to MS for Iowa showed significant
decrease in stalk lodging, while in Portugal ear length significantly decreased, whereas ear diameter, kernel-row number,
and fasciation level significantly increased. Selection also significantly increased days-to-silk and anthesis in Portugal.
Response to S2RS in Portugal significantly increased days-to-silk, uniformity, and cob/ear weight ratio. These results showed
that the methods used by farmer and breeder were not effective for significant yield increase, but the ear size increased
significantly for MS and showed a positive tendency for S2RS. Adaptation to farmer needs was maintained for the last cycles
of selection. 相似文献
2.
T. Miedaner F. Wilde V. Korzun E. Ebmeyer M. Schmolke L. Hartl C. C. Schön 《Euphytica》2009,166(2):219-227
Fusarium head blight (FHB) infects all cereals including maize and is considered a major wheat disease, causing yield losses and mycotoxin
contamination. This study aimed to compare the realized selection gain from marker and phenotypic selection in European winter
wheat. A double cross (DC) combined three FHB resistance donor-QTL alleles (Qfhs.lfl-6AL and Qfhs.lfl-7BS from ‘Dream’, and one QTL on chromosome 2BL from ‘G16-92’) with two high yielding, susceptible winter wheats, ‘Brando’ and
‘LP235.1’. The base population of 600 DC derived F1 lines was on one hand selected for the respective QTLs by SSR markers (marker-selected cycle, CM), resulting in 35 progeny
possessing different combinations of beneficial donor-QTL alleles. On the other hand it was selected phenotypically, only
by FHB rating, and the best 20 lines were recombined and selfed (phenotypically selected cycle, CP). The variants CP, CM,
and an unselected variant (C0) were tested at four locations by inoculation of Fusarium culmorum. Resistance was measured as the mean of multiple FHB ratings (0–100%). FHB severity was reduced through both phenotypic and
marker selection by 6.2 vs. 5.0%, respectively. On a per-year basis, marker selection by 2.5% was slightly superior to phenotypic
selection with 2.1%, because the first variant saved 1 year. Marker-selected lines were on average 8.6 cm taller than phenotypically
selected lines. A high genetic variation within the marker-selected variant for FHB resistance and the high effect of a resistance-QTL
allele on straw length indicate that additional phenotypic selection will further enhance selection gain. 相似文献
3.
Assessing the genetic diversity of Portuguese maize germplasm using microsatellite markers 总被引:4,自引:0,他引:4
A collection of Portuguese maize accessions representing a valuable source of genes for introduction into modern cultivars
is stored at the Portuguese Plant Germplasm Bank (Banco Português de Germoplasma Vegetal—BPGV). To assess genetic diversity
among inbreds, microsatellite analysis was carried out for 54 inbred lines representing the diversity of Portuguese dent and
flint maize germplasm. Fifty American and other European elite inbreds were also analysed for comparison. Fifteen microsatellite
loci distributed throughout the maize genome were chosen based on their repeat unit and base composition. A total of 80 alleles
were detected with an average allele number of 5.33 per locus. Polymorphism information content (PIC) values and observed
genetic distances showed the existence of large variability among inbreds. Cluster analysis indicated that almost all of the
inbreds could be distinguished from each other and Portuguese inbreds were present in all clusters formed. These associations
were consistent with the known pedigree records of the inbreds, confirming a mixed origin of Portuguese materials. Comparative
analysis of microsatellite diversity among groups was established according to important traits for both breeding and line
identification. This revealed that, although most of the genetic diversity (>95%) was attributable to differences among inbreds
of different groups, the existence of phenotypic differentiation in endosperm colour, kernel type and cob colour could be
suggested for grouping. These findings support the joint use of molecular and morphological traits in management of the germplasm
collection. In this study, SSR markers proved to be effective to characterise and identify maize inbred lines, and demonstrate
associations among them.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
4.
In order to investigate the effect of long term recurrent selection on the pattern of gene diversity, thirty randomly-selected
individuals from the progenitors (p) and four selection cycles (C0, C3, C6 and C11) were sampled for DNA analysis from the
tropical maize (Zea mays L.) breeding populations, Atherton 1 (AT1) and Atherton 2 (AT2). Fifteen polymorphic Simple Sequence Repeat markers amplified
a total of 284 and 257 alleles in AT1 and AT2 populations, respectively. Reductions in the number of alleles were observed
at advanced selection cycles. About 11 and 12% of the alleles in AT1 and AT2 populations respectively, were near to fixation.
However, a higher number of alleles (37% in AT1 and 33% in AT2) were close to extinction. Fisher’s exact test and analysis
of molecular variance (AMOVA) showed significant population differentiations. Gene diversity estimates and AMOVA revealed
increased genetic differentiations at the expense of loss of heterozygosity. Population differentiations were mainly due to
fixation of complementary alleles at a locus in the two breeding populations. The estimates of effective population at an
advanced selection cycle were close to the population size predicted by the breeding method. 相似文献
5.
Based on polyacrylamide gel electrophoresis, nine natural populations of Atriplex halimus L., a perennial shrub, collected in different regions of Morocco, were studied for their genetic variation using isoenzyme
polymorphism of the highly active enzyme systems: esterases (EST), acid phosphatases (ACP) and glutamate oxaloacetate transaminase
(GOT). Different allozyme frequencies from 7 different loci were obtained for all populations of this halophyte species. High
levels of genetic diversity were revealed. The mean number of alleles per locus (A = 1.9–2.0), the percentage of polymorphic
loci (p = 71.4–85.7) and the mean expected heterozygosity (He = 0.339–0.385) showed an important variability in all populations. Gene diversity was essentially explained by the within
population component. The between populations differentiation accounted for 8% of the whole diversity (FST, averaged over all loci, is 0.08). The relationships among the 9 populations were inferred from the Nei’s genetic distances.
Four major groups were formed. The northern population ‘Tanger’, forming a unique group, was highly divergent from the other
groups. It appeared that the genetic distance between all groups was related to the geographic distance that separates them.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
6.
Maize participatory breeding in Portugal: Comparison of farmer's and breeder's on‐farm selection
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Pedro Mendes‐Moreira Zlatko Satovic João Mendes‐Moreira João Pedro Santos João Pedro Nina Santos Silas Pêgo Maria Carlota Vaz Patto 《Plant Breeding》2017,136(6):861-871
“VASO” is a Portuguese participatory maize breeding project (1984), where several maize landraces such as “Pigarro” have been selected both by a farmer's (phenotypic recurrent selection) and a breeder's approach (S2 lines recurrent selection). The objectives of this study were to determine the phenotypic and genotypic responses to participatory selection using these two different approaches, to clarify to which extent both selection methods preserve genetic diversity, and conclude what is the preferred method to apply in sustainable farming systems. The results, obtained via ANOVA, regression analyses and molecular markers, indicate that for both selection methods, genetic diversity was not significantly reduced, even with the most intensive breeder's selection. Although there were some common outputs, such as the determinated versus indeterminated ears, cob and ear weight ratio per ear and rachis 2, specific phenotypic traits evolved in opposite directions between the two selection approaches. Yield increase was only detected during farmer selection, indicating its interest on PPB. Candidate genes were identified for a few of the traits under selection as potential functional markers in participatory plant breeding. 相似文献
7.
D. Sharma R. C. Sharma R. Dhakal N. B. Dhami D. B. Gurung R. B. Katuwal K. B. Koirala R. C. Prasad S. N. Sah S. R. Upadhyay T. P. Tiwari G. Ortiz-Ferrara 《Euphytica》2008,164(3):689-698
The national maize improvement program in Nepal regularly receives elite maize (Zea mays L.) genotypes from CIMMYT and other countries and tests them for their performance stability in highly diverse environments.
Studies were conducted on research stations and farmers’ fields at five sites in three years to determine performance stability
of exotic maize genotypes. Replicated on-station and on-farm studies were conducted using 25 and 10 genotypes, respectively,
including a local check and an improved check (Manakamana-3), in 2004–2006. We analyzed grain yield, days to flowering, plant
and ear height, plant population, husk cover, and plant and ear aspect. Stability and genotype superiority for grain yield
was determined using genotype and genotype × environment (GGE) biplot analysis that compares among a set of genotypes with
a reference ‘ideal’ genotype, which has the highest average value of all genotypes and is absolutely stable. Several genotypes
produced significantly higher grain yield than the local check. Four genotypes (‘Across9942 × Across9944’, ‘Open Ended White
Hill Population’, ‘Population 44C10’ and ‘ZM621’), that produced significantly higher grain yield than the improved check,
also had other agronomic traits (days to flowering, plant and ear height, number of ears, resistance to leaf blight, plant
and ear aspect and husk cover tightness) equal to or better than the improved check. GGE-biplot analysis showed that Across9942 × Across9944
and ZM621 were the most superior genotypes in the on-station and on-farm trials, respectively. The findings from this study
provide new information on the stability of the maize genotypes that are also adapted to other regions of the world. Such
information could be useful for maize improvement program for the highlands in Nepal and other similar environments. 相似文献
8.
Aluminium (Al) toxicity is a major constraint to crop productivity in acidic soils. A quantitative trait locus (QTL) analysis
was performed to identify the genetic basis of Al tolerance in the wheat cultivar ‘Chinese Spring’. A nutrient solution culture
approach was undertaken with the root tolerance index (RTI) and hematoxylin staining method as parameters to assess the Al
tolerance. Using a set of D genome introgression lines, a major Al tolerance QTL was located on chromosome arm 4DL, explaining
31% of the phenotypic variance present in the population. A doubled haploid population was used to map a second major Al tolerance
QTL to chromosome arm 3BL. This major QTL (Qalt
CS
.ipk-3B) in ‘Chinese Spring’ accounted for 49% of the phenotypic variation. Linkage of this latter QTL to SSR markers opens the possibility
to apply marker-assisted selection (MAS) and pyramiding of this new QTL to improve the Al tolerance of wheat cultivars in
breeding programmes. 相似文献
9.
Mun Sup Yoon Jeongran Lee Chang Yung Kim Jung Hoon Kang Eun Gi Cho Hyung Jin Baek 《Euphytica》2009,165(1):69-77
Approximately 7,000 accessions of Korean soybean (Glycine max (L.) Merrill) landraces, largely composed of three collections, the Korea Atomic Energy Research Institute’s soybean (KAS),
the Korean Crop Experiment Station’s soybean (KLS) and the Korean Agricultural Development and Technology Center’s soybean
(KADTC) collections, have been conserved at the Rural Development Administration (RDA) genebank in Korea. The accessions within
collections were classified based on their traditional uses such as sauce soybean (SA), sprouted soybean (SP), soybean for
cooking with rice (SCR), and OTHERS. A total of 2,758 accessions of Korean soybean landraces were used to profile and to evaluate
genetic structure using six SSR loci. A total of 110 alleles were revealed by at the six SSR loci. The number of alleles per
SSR locus ranged from 9 to 39 in Satt187 and Satt_074, respectively. The number of alleles ranged from 87 in the KADTC collection
to 96 in the KLS collection, and from 63 in the SCR group to 95 in the SP group. Nei’s average genetic diversity ranged from
0.68 to 0.70 across three collections, and 0.64 to 0.69 across the usage groups. The average between-group differentiation
(G
st) was 0.9 among collections, and 4.1 among the usage groups. The similar average diversity among three collections implies
that the genetic background of the three collections was quite similar or that there were a large number of duplicate accessions
in three collections. The selection from the four groups classified based upon usage may be a useful way to select accessions
for developing a Korean soybean landrace core collection at the RDA genebank. DNA profile information of accessions will provide
indications of redundancies or omissions and aid in managing the soybean collection held at the RDA genebank. The information
on diversity analysis could help to enlarge the genetic diversity of materials in breeding programs and could be used to develop
a core collection. 相似文献
10.
Hoy-Taek Kim Yutaka Hirata Yong-Uk Shin Hae-Sung Hwang Jeong-Hwan Hwang Il-Sheob Shin Dae-Il Kim Sang-Jo Kang Hyun-Jung Kim Dong-Young Shin Ill-Sup Nou 《Euphytica》2004,138(1):73-80
The pear cultivar ‘Osa-Nijisseiki’ (S2Ssm
4; sm = stylar-part mutant) has been used as a parent to breed self-compatible cultivars that produce excellent fruits. However,
determination of the self-compatibility of ‘Osa-Nijisseiki’ offspring requires a lot of time, 6 years or more, by conventional
cross breeding. We have designed a rapid reliable method for the identification of self-compatible varieties of ‘Osa-Nijisseiki’
offspring based on the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) with S-allele specific
restriction endonucleases. By using this method, 8 self-compatible varieties were selected among 16 selections resulting from
a cross between the self-compatible cultivar ‘Osa-Nijisseiki’ (S2Ssm
4) and the self-incompatible cultivars ‘Niitaka’ (S3S9), ‘Whasan’ (S3S5), ‘Chuwhangbae’ (S4S6). The S-genotypes of 16 ‘Osa-Nijisseiki’ offsprings were also determined.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
11.
Celso Lopes de Albuquerque Frederico Denardi Adriana Cibele de Mesquita Dantas Rubens Onofre Nodari 《Euphytica》2011,181(2):277-284
Apple plants are self-incompatible because a genetic mechanism allows the female reproductive organ to recognize and reject
self-pollen or pollen from genetic related individuals and allows non-self pollen to effect fertilization. Thus, there are
implications to both breeding strategies and orchard management for fruit production. The purpose of this study was to identify
and to characterize the S-RNase alleles of the gametophytic incompatibility among apple cultivars developed in Brazil, seeking
to give support for choosing right combinations of parent in the apple breeding programs. It also sought to identify correct
combinations of scion/pollinator cultivars of commercial apple orchards. A total of 16 specific S-RNase alleles primers were
tested against DNA extracted from 12 Brazilian cultivars and their parents. The molecular analysis confronted to the reference
cultivars, showed that the cultivars Daiane, Imperatriz and Princesa have the same incompatibility S3 and S5 alleles, while
‘Lisgala’ showed the alleles S2 and S5; ‘Suprema’, S1 and S9; ‘Catarina’, S1 and S19; ‘Joaquina’ and ‘Fred Hough’, S5 and
S19; ‘Baronesa’, S3 and S9; ‘Duquesa’, S2 and S3. For ‘Primícia’ and ‘Condessa’ it was only possible to identify one of the
S-alleles, namely S24 and S2, respectively, with the second allele remaining to be identified. Progeny test indicated the
Mendelian inheritance for RNase alleles. Results of this study will be helpful to judiciously choose parents in apple breeding
programs to improve compatibility. 相似文献
12.
Phenotypic and genotypic analysis of a commercial cultivar and wild populations of Anemone coronaria
Yonash Nissim Fang Jinggui Shamay Arik Pollak Neta Lavi Uri Cohen Avner 《Euphytica》2004,136(1):51-62
Seven wild populations of Anemonecoronaria were assessed for 11 phenotypic traits, most of them having economic value for the flower industry. The wild populations
were sampled to represent the diversity in habitats, climates, rock and soil types, terrains, and elevations in Israel. AFLP
analysis was carried out on 12 individuals from each of six out of the seven wild populations and for six individuals from
the commercial cultivar ‘Mona-Lisa’. It was found that the Dorot population, which is located in the area bordering the semi-arid
zone at the very end of the species distribution, exhibits extreme and different phenotypes with relatively low variability
compared withthe other wild populations. The other six wild populations, that grow in more favorable geographic and climatic
conditions exhibit phenotypes with larger plants, larger numbers of flowers and less dissected leaves. These populations were
less uniform than that of Dorot. Genetic characterization by AFLP markers revealed a total of 165 bands. The wild populations
exhibit wide variation within-population, with about 80% polymorphic bands and average gene diversity between pairs of about
30%. The Dorot population has the lowest genetic variation and the Megido population the highest. Thus, the phenotypic variation
reflects the genetic variation. The cultivar ‘Mona-Lisa’, as expected, has much lower genetic variation. The Dorot population
and the ‘Mona-Lisa’ cultivar were found to have the largest genetic distances from the other wild populations, and the highest
genetic variation between themselves. Phenetic analysis yielded a dendrogram describing the genetic relatedness of these populations.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
13.
European flint maize (Zea mays L.)cannot be considered an uniform group of germplasm based on its origin and area of adaptation. However, maize breeders
have not taken full advantage of the variability within the European flint germplasm. The objective of this work was to study
the heterotic relationships among European maize inbreds from different origins. Nine European flint inbreds were crossed
in a diallel that was evaluated in three environments in northwestern Spain. The variability within the European flint germplasm
and the agronomic value of some inbreds could be utilized for maize breeding programs as an alternative to the systematic
introduction of U.S. dent germplasm that is narrowing the germplasm base of breeding programs even in places where it is poorly
adapted. Some European flint inbreds may also be valuable sources of earliness (F7 and EP42), resistance to root lodging (EA1070),
and yield (EP42).These results suggest that, within the European flint germplasm, there could be some heterotic patterns,
such as ‘north-central Europe × southern Europe’, which could provide an alternative to the heterotic pattern ‘European flint
× U.S. dent’.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
14.
Juthaporn Khampila Kamol Lertrat Weerasak Saksirirat Jirawat Sanitchon Nooduan Muangsan Piyada Theerakulpisut 《Euphytica》2008,164(3):615-625
Exserohilum turcicum causes northern corn leaf blight (NCLB), an important disease occurring in maize producing areas throughout the world. Currently,
the development of cultivars resistant to E. turcicum seems to be the most efficient method to control NCLB damage. Marker-assisted selection (MAS) enables breeders to improve
selection efficiency. The objective of this work was to identify random amplified polymorphic DNA (RAPD) and sequence characterized
amplified region (SCAR) markers associated with NCLB resistance. Bulked segregant analysis (BSA) was used to search for RAPD
markers linked to NCLB resistance genes, using F2 segregating population obtained by crossing a susceptible inbred ‘209W’ line with a resistant inbred ‘241W’ line. Two hundred
and twenty-two decamer primers were screened to identify four RAPD markers: OPA07521, OPA16457, OPB09520, and OPE20536 linked to NCLB resistance phenotype. These markers were converted into dominant SCAR markers: SCA07496, SCA16420, SCB09464, and SCE20429, respectively. The RAPD and SCAR markers were developed successfully to identify NCLB resistant genotypes in segregating
progenies carrying NCLB resistant traits. Thus, the markers identified in this study should be applicable for MAS for the
NCLB resistance in waxy corn breeding programs. 相似文献
15.
Fourteen developed microsatellite markers were characterized for their use in genotyping and diversity studies of olive varieties.
After optimisation of microsatellite assay and allele sizing, ninety-six alleles were found in nineteen varieties, with an
average of 6.8 alleles per locus. The characteristics of the microsatellite markers were used to identify markers that can
be reliably applied for variety genotyping. Such features were the generation of complex banding patterns supported by underlying
allele sequences, `short allele dominance', an unstable repeat structure and a low number of alleles. AFLP analysis was performed
on the same set of olive varieties using eight primer pair combinations. The genetic relationships among nineteen olive varieties
were compared on the basis of microsatellite and AFLP polymorphisms. Genetic distances between all pairwise combinations of
the varieties were calculated using Jaccard's coefficient of similarity and dendrograms were constructed by the UPGMA method.
The results of clustering analysis with both molecular systems showed the common genetic background of Tuscan varieties, and
genetic divergence within Slovene olive germplasm. Slovenian varieties ‘Buga’, ‘Štorta’ and ‘Samo’ might represent regionally
selected olives, while ‘Zelenjak’ and ‘Črnica’ are probably derived from the Central Italian region. The predominant local
‘Istrska belica’ was introduced to Slovenia independently from the other regional varieties and showed the lowest genetic
similarity with the other regional varieties.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
16.
Trygve Berg 《Euphytica》2009,166(3):423-430
Farmers’ seeds are most often lumped together in one broad category called ‘landraces’. But such a category covers variety
types that reflect different levels of farmer involvement. Those differences matters when we discuss such issues as genetic
erosion, on-farm conservation and seed related policies. The term landrace can be traced to the time when ‘modern’ varieties
of cereals were introduced to European farmers in the late nineteenth century. The farmers’ varieties of the time were called
‘landraces’ and understood as seeds adapted to local growing conditions through natural adaptation usually with no intentional
selection. But the term was quickly adopted as generic for all farmers’ varieties including those that are bred and maintained
by active seed selection on-farm. Such farmer-bred varieties are better termed ‘folk varieties’. The article discusses how
interaction of crop characteristics and developing technologies resulted in the evolution of crop varieties as either landraces
or folk varieties. It is argued that vulnerability to different agents of genetic erosion and feasibility of on-farm conservation
are clearly different for the two categories of farmers’ varieties. Likewise seed policies, particularly the issue of Farmers’
Rights would benefit from clarity of type of farmers’ varieties. 相似文献
17.
‘Conrad’, a soybean cultivar tolerant to Phytophthora root rot (PRR), and ‘OX760-6-1’, a breeding line with low tolerance
to PRR, were crossed. F2 derived recombinant inbred lines were advanced to F6 to generate a population through single-seed descent. This population was used to identify quantitative trait loci (QTLs)
influencing PRR tolerance in ‘Conrad’. A total of 99 simple sequence repeat (SSR), or microsatellite, markers that were polymorphic
and clearly segregated in the F6 mapping population were used for QTL detection. Based on the data of PRR in the field at two planting locations, Woodslee
and Weaver, for the years 2000 and 2001, one putative QTL, designated as Qsatt414-596, was detected using MapMaker/QTL. Qsatt414-596
was flanked by two SSR markers from the linkage group MLG J, Satt414 and Satt596. Satt414 and Satt596 were also detected to
be significantly (P < 0.005) associated with PRR using the SAS GLM procedure and were estimated to explain 13.7% and 21.5% of the total phenotypic
variance, respectively. 相似文献
18.
While the roles of sugars and acids in fruit flavour are well known and described, the roles of volatile compounds that contribute
to flavour and odour are more difficult to define. The determination of volatiles that make a significant contribution to
the flavour of kiwifruit (Actinidia chinensis) is essential for efficient and cost effective flavour breeding. The aims of this study were to explore associations between
volatile compounds, sensory and fruit attributes of A. chinensis fruit and to identify potential key flavour impact volatiles, superior parents and selection methods, using multivariate
analysis. We investigated the volatiles produced by ripe fruit of 24 genotypes selected by principal component analysis (PCA)
to represent the diversity of taste and fruit characteristics in a breeding population. Seventy-two volatiles were detected.
Extended use of multivariate analysis proved powerful for gaining maximum information from the limited plant material. The
volatiles were successfully grouped into four clusters, using hierarchical clustering of variables based on phenotypic correlations
between volatiles to avoid a singular correlation matrix in PCA. Based on these clusters, associations between volatiles,
sensory and fruit attributes were explored using PCA and multiple linear regressions. Principal components provided a measure
of the balance of complex volatiles that is likely to affect consumer responses. Thirteen potential key impact volatiles that
made a substantial contribution to the flavour of A. chinensis fruit were identified. Five esters were strongly associated with the flavours and odours characteristic of ‘Hort16A’. Volatiles
associated with ‘sour taste’, ‘fruit ripeness’, ‘atypical ‘Hort16A’-like odour’ and ‘atypical kiwifruit flavour’ were also
recognized. Parents with potentially desirable volatile profiles and a possible selection method for flavour breeding were
identified. 相似文献
19.
In order to identify the markers linked to microspore embryogenic ability in Brassica crops, RAPD segregation analyses were performed in a microspore-derived (MD) population and a F2 population derived from F1between ‘Ho Mei’ (high responsive parent in microspore embryogenesis) and ‘269’ (low responsive parent) in Chinese cabbage,
and between ‘Lisandra’ (high responsive parent) and ‘Kamikita’ (low responsive parent) in oil seed rape. After 230 and 143
primers were screened, a total of 148 and 52markers were detected to be polymorphic between the parents in Chinese cabbage
and oilseed rape, respectively. Twenty-seven percent of the markers in the MD population showed a significant segregation
distortion in both crops. Of the markers showing segregation distortion in the MD population, 71–75% of the markers followed
the expected Mendelian segregation ratio in the F2 population. When the relationships between such distorted markers and microspore embryogenesis of the F2 population were examined, 7 and 3 markers were identified to be associated with embryogenic ability in Chinese cabbage and
oilseed rape, respectively. These markers showed additive effects on embryo yields, and the plants having more alleles of
the high responsive parent produced higher embryo yields. These markers maybe useful in marker-assisted selection for improving
microspore responsiveness straits in Brassica crops.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
20.
There is a need to identify genetic markers that can assist coconut (Cocos nucifera L.) breeding programs. With that objective,
electrophoretic patterns of leaf peroxidases, endopeptidases and coomassie blue stained proteins were analysed in four cultivars
(‘West African Tall’, ‘Rennell Tall’, ‘Malayan Yellow Dwarf’, ‘Cameroon Red Dwarf’), and in the hybrids PB121 (‘Malayan Yellow
Dwarf’ × ‘West African Tall’) and PB111 (‘Cameroon Red Dwarf’ × ‘West African Tall’). The polymorphisms detected fit the expression
of two alleles of a dimeric peroxidase, two alleles of a monomeric endopeptidase, and a pair of active and null alleles of
a coomassie blue stained protein. Four distinctive genotypes were identified. One for each of the tall cultivars, another
for both of the dwarf cultivars, and the last for both of the hybrids. Applications of the markers in breeding programs, and
in research concerning reproductive biology and phylogeny, are discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献