共查询到20条相似文献,搜索用时 15 毫秒
1.
T. S. Cox J. P. Murphy 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1990,79(2):241-250
Summary In winter wheat (Triticum aestivum L.), the development of a methodology to estimate genetic divergence between parental lines, when combined with knowledge of parental performance, could be beneficial in the prediction of bulk progeny performance. The objective of this study was to relate F2 heterosis for grain yield and its components in 116 crosses to two independent estimates of genetic divergence among 28 parental genotypes of diverse origins. Genetic divergence between parents was estimated from (a) pedigree relationships (coefficients of kinship) determined without experimentation, and (b) quantitative traits measured in two years of field experimentation in Kansas and North Carolina, USA. These distances, designated (1 -r) and G, respectively, provided ample differentiation among the parents. The 116 F2 bulks were evaluated at four locations in Kansas and North Carolina in one year. Significant rank correlations of 0.46 (P = 0.01) and 0.44 (P = 0.01) were observed between G and grain yield and kernel number heterosis, respectively. Although (1 -r) was poorly associated with grain yield heterosis, G and midparent performance combined to account for 50% of the variation in F2 yields among crosses when (1 -r) was above the median value, whereas they accounted for only 9% of the variation among crosses when (1-r) was below the median. Midparent and (1 -r) had equal effects on F2 grain yield (R
2= 0.40) when G was greater than the median value. A breeding strategy is proposed whereby parents are first selected on the basis of performance per se and, subsequently, crosses are made between genetically divergent parents that have both large quantitative (G) and pedigree divergence (1 -r).Paper No. 12162 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, NC 27695-7643, and Contribution No. 89-396-J of the Kansas Agricultural Experiment Station, Manhattan, KS 66506 相似文献
2.
Genetic differentiation along environmental clines is often observed as a result of interplay between gene flow and natural
selection. In order to understand the relative roles of these processes in shaping this differentiation, we designed a study
in which we used two approaches that have not previously been combined, the Q
ST–F
ST comparison and crossbreeding. We examined (1) interpopulation phenotypic and genetic (AFLP) variation, and (2) performance
of interpopulation hybrids in a common annual Senecio glaucus. Fitness of interpopulation hybrids (F1 and F2) was tested under simulated population natural conditions in terms of aridity
and analyzed for a relationship with (1) spatial distance and (2) environmental differences (amount of annual rainfall). While
phenotypic variation corresponded to the clinal changes in aridity along population locations, viz. narrower and longer leaves,
longer leaf outgrowths and advanced flowering in more arid environments, the F
ST < 0.1 calculated from AFLP data suggested intensive interpopulation gene flow, with little if any contribution of genetic
drift. Performance of hybrids in simulated natural environments revealed heterosis in F1, but a hybrid breakdown in F2 generation.
These effects were related to both the spatial distance between hybrid parents and their population rainfall differences.
The detected clinal phenotypic variation and outbreeding depression in F2 strongly support presence of aridity-induced clinal
natural selection, which is matched by the observed Q
ST ≫ F
ST. From this we conclude that Q
ST–F
ST comparison can detect effect of diversifying selection when patterns of phenotypic variation across sampled locations can
be reliably predicted from environmental variation. 相似文献
3.
High accuracy of predicting hybrid performance of Fusarium head blight resistance by mid-parent values in wheat 总被引:3,自引:0,他引:3
Thomas Miedaner Albert W. Schulthess Manje Gowda Jochen C. Reif C. Friedrich H. Longin 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2017,130(2):461-470
Key message
Mid-parent values of Fusarium head blight (FHB) resistance tested across several locations are a good predictor of hybrid performance caused by a preponderance of additive gene action in wheat.Abstract
Hybrid breeding is intensively discussed as one solution to boost yield and yield stability including an enhanced biotic stress resistance. Our objectives were to investigate (1) the heterosis for Fusarium head blight (FHB) resistance, (2) the importance of general (GCA) vs. specific combining ability (SCA) for FHB resistance, and (3) the possibility to predict the FHB resistance of the hybrids by the parental means. We re-analyzed phenotypic data of a large population comprising 1604 hybrids and their 120 female and 15 male parental lines evaluated in inoculation trials across seven environments. Mid-parent heterosis of FHB severity averaged ?9%, with a range from ?36 to +35%. Mean better parent heterosis was 2% and 78 of the hybrids significantly (P < 0.05) outperformed the best commercial check variety included in our study. FHB resistance was not correlated with grain yield in healthy status for lines (r = 0.01) and hybrids (r = 0.09, P < 0.01). While a preponderance of GCA variance (P < 0.01) was found, SCA variance was not significantly different from zero. Accuracy to predict hybrid performance of FHB severity based on mid-parent values and on GCA effects was high (r = 0.70 and 0.86, respectively; P < 0.01). Similarly, line per se performance and GCA effects were significantly correlated (r = 0.77; P < 0.01). The substantial level of mid-parent heterosis in the desired direction of decreased susceptibility and the negligible better parent heterosis suggest that hybrids are an attractive alternative variety type to improve FHB resistance.4.
Xiaojie Li Guanpin Yang Yuanyuan Shi Yizhou Cong Shi Che Shancun Qu Zhiling Li 《Journal of applied phycology》2008,20(6):1097-1102
Eighteen microsatellite markers were used to determine the genetic distances between the parental gametophyte clones of 14
Laminaria hybrids, which were then used to establish a linear relationship with the heterosis (hybrid vigor) of economic traits including
yield, mean blade try weight, mean blade fresh weight, blade length, blade width and mean blade thickness using regression
analysis. Significant regression was found between the genetic distance (x) and the heterosis (y) of yield (y = 115.10x − 77.97,
r = 0.8151, p = 0.00038), mean blade dry weight (y = 115.23x −77.97, r = 0.8154, p = 0.00038), mean blade fresh weight (y = 100.08x − 57.85, r = 0.7306, p = 0.0030) and blade length (y = 204.11x − 46.77, r = 0.6963, p = 0.00566). The prediction of the heterosis of Laminaria hybrids with the genetic distance between parental gametophyte clones will facilitate the selection of elite Laminaria hybrids by avoiding the time-consuming and labor-intensive trait evaluation of a large number of hybridization combinations. 相似文献
5.
A. E. Melchinger R. K. Gumber R. B. Leipert M. Vuylsteke M. Kuiper 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(3-4):503-512
Prediction of the means and genetic variances in segregating generations could help to assess the breeding potential of base
populations. In this study, we investigated whether the testcross (TC) means and variances of F3 progenies from F1 crosses in European maize can be predicted from the TC means of their parents and F1 crosses and four measures of parental genetic divergence: genetic distance (GD) determined by 194 RFLP or 691 AFLPTM
1 markers, mid-parent heterosis (MPH), and absolute difference between the TC means of parents (∣P1−P2∣). The experimental materials comprised six sets of crosses; each set consisted of four elite inbreds from the flint or dent
germplasm and the six possible F1 crosses between them, which were evaluated for mid-parent heterosis. Testcross progenies of these materials and 20 random
F3 plants per F1 cross were produced with a single-cross tester from the opposite heterotic group and evaluated in two environments. The characters
studied were plant height, dry matter content and grain yield. The genetic distance between parent lines ranged between 0.17
and 0.70 for RFLPs and between 0.14 and 0.57 for AFLPs in the six sets. Testcross-means of parents, F1 crosses, and F3 populations averaged across the six crosses in a particular set generally agreed well for all three traits. Bartlett’s test
revealed heterogeneous TC variances among the six crosses in all sets for plant height, in four sets for grain yield and in
five sets for dry matter content. Correlations among the TC means of the parents, F1 crosses, and F3 populations were highly significant and positive for all traits. Estimates of the TC variance among F3 progenies for the 36 crosses showed only low correlations with the four measures of parental genetic divergence for all traits.
The results demonstrated that for our material, the TC means of the parents or the parental F1 cross can be used as predictors for the TC means of F3 populations. However, the prediction of the TC variance remains an unsolved problem.
Received: 4 August 1997 / Accepted: 17 November 1997 相似文献
6.
Sarita K. Pandey Tapash Dasgupta Abhishek Rathore Anilkumar Vemula 《Biochemical genetics》2018,56(3):188-209
The genetic distance analysis for selection of suitable parents has been established and effectively used in many crops; however, there is dearth of conclusive report of relationship of genetic distance analysis with heterosis in sesame. In the present study, an attempt was made to estimate the associations of genetic distances using SSR (GDSSR), seed-storage protein profiling (GDSDS) and agro-morphological traits (GDMOR) with hybrid performance. Seven parents were selected from 60 exotic and Indian genotypes based on genetic distance from clustering pattern based on SSR, seed-storage protein, morphological traits and per se performance. For combining ability analysis, 7 parents and 21 crosses generated from 7 × 7 half diallel evaluated at two environments in a replicated field trial during pre-kharif season of 2013. Compared with the average parents yield (12.57 g plant?1), eight hybrids had a significant (P < 0.01) yield advantage across environments, with averages of 26.94 and 29.99% for better-parent heterosis (BPH) and mid-parent heterosis (MPH), respectively, across environments. Highly significant positive correlation was observed between specific combining ability (SCA) and per se performance (0.97), while positive non-significant correlation of BPH with GDSSR (0.048), and non-significant negative correlations with GDMOR (? 0.01) and GDSDS (? 0.256) were observed. The linear regressions of SCA on MPH, BPH and per se performance of F1s were significant with R2 value of 0.88, 0.84 and 0.95 respectively. The present findings revealed a weak association of GDSSR with F1’s performance; however, SCA has appeared as an important factor in the determination of heterosis and per se performance of the hybrids. The present findings also indicated that parental divergence in the intermediate group would likely produce high heterotic crosses in sesame. 相似文献
7.
R. K. Gumber B. Schill W. Link E. v. Kittlitz A. E. Melchinger 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(3-4):569-580
Determining the genetic potential of a base population from the properties of their parental lines would improve the efficiency
of a breeding program. In the present study, we investigated whether the means of the parents and the genetic distance determined
from RAPD data (GD) or multivariate analysis (Mahalanobis D2), mid-parent heterosis (MPH), and the absolute difference between means of the parents (∣P1−P2∣) can be used for predicting the means and genetic variances (σ^2
g
) of F3:4 lines derived from different crosses in faba beans. The material comprised 18 intra- and 18 inter-pool crosses among lines
from the Minor, Major, and Mediterranean germplasm pools. Fifty F3:4 lines from each cross were evaluated for days to anthesis, plant height, seeds per plant, and seed yield in German (GE) and
Mediterranean (ME) environments. GD estimates between parent lines ranged from 0.38 to 0.58, while D2 ranged from 45.5 to 134.7. Correlations between means of the parents and F3:4 lines were highly significant for most traits. Estimates of σ2
g
for all traits showed non-significant correlations with MPH, GD, D2. In one ME, ∣P1−P2∣ had significant associations with σ^2
g
for seed yield and days to anthesis. The predicted usefulness of crosses, defined as the sum of the population mean and selection
responses, was most closely associated with the means of F3:4 lines. We conclude from this study that the means of F3:4 lines can be predicted from the means of the parents, whereas the prediction of genetic variance is still an unsolved problem
Received: 12 December 1997 / Accepted: 13 July 1998 相似文献
8.
Khaled M. Al-Qudah Ahmad A. Gharaibeh Maysa’a M. Al-Shyyab 《Biological trace element research》2010,136(1):40-47
The aim of this study was to determine the levels of trace minerals Zn, Cu, and Se, the effect of dermatophytosis on the level
of thiobarbituric acid reactive substances (TBARS) as an indicator of lipid peroxidation, the status of enzymatic and nonenzymatic
antioxidants, and the relationship between the mentioned trace minerals and antioxidant defense system in calves with dermatophytosis.
A total of 21 Holstein calves with clinically established diagnosis of dermatophytosis and an equal number of healthy ones
were included in this study. Results showed that 81% of mycotic isolates were Trichophyton verrucosum, while 19% were Trichophyton mentagrophytes. The level of Zn, Cu, Se, and glutathione (GSH) and the activity of the antioxidant enzymes, glutathione peroxidase (GSH-Px),
and superoxide dismutase (SOD) were significantly (P ≤ 0.05) lower. The plasma level of TBARS was significantly (P ≤ 0.05) higher in dermatophytic calves compared to healthy controls. SOD activity was fairly correlated with serum Cu and
positively correlated with serum Zn in healthy control (r = 0.68, P ≤ 0.05; r = 0.58, P ≤ 0.05) and in calves affected with dermatophytosis (r = 0.73, P ≤ 0.05; r = 0.55, P ≤ 0.05), respectively. GSH-Px activity was highly correlated with whole blood selenium (r = 0.78, P ≤ 0.05) in healthy control and dermatophytic subjects (r = 0.76, P ≤ 0.05). Our results demonstrated that in dermatophytosis, the alteration in the antioxidant enzyme activities might be secondary
to changes in their cofactor concentrations. 相似文献
9.
Qian W Sass O Meng J Li M Frauen M Jung C 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,115(1):27-34
Chinese semi-winter rapeseed is genetically diverse from Canadian and European spring rapeseed. This study was conducted to
evaluate the potential of semi-winter rapeseed for spring rapeseed hybrid breeding, to assess the genetic effects involved,
and to estimate the correlation of parental genetic distance (GD) with hybrid performance, heterosis, general combining ability
(GCA) and specific combining ability (SCA) in crosses between spring and semi-winter rapeseed lines. Four spring male sterile
lines from Germany and Canada as testers were crossed with 13 Chinese semi-winter rapeseed lines to develop 52 hybrids, which
were evaluated together with their parents and commercial hybrids for seed yield and oil content in three sets of field trials
with 8 environments in Canada and Europe. The Chinese parental lines were not adapted to local environmental conditions as
demonstrated by poor seed yields per se. However, the hybrids between the Chinese parents and the adapted spring rapeseed
lines exhibited high heterosis for seed yield. The average mid-parent heterosis was 15% and ca. 50% of the hybrids were superior
to the respective hybrid control across three sets of field trials. Additive gene effects mainly contributed to hybrid performance
since the mean squares of GCA were higher as compared to SCA. The correlation between parental GD and hybrid performance and
heterosis was found to be low whereas the correlation between GCA(f + m) and hybrid performance was high and significant in each set of field trials, with an average of r = 0.87 for seed yield and r = 0.89 for oil content, indicating that hybrid performance can be predicted by GCA(f + m). These results demonstrate that Chinese semi-winter rapeseed germplasm has a great potential to increase seed yield in spring
rapeseed hybrid breeding programs in Canada and Europe. 相似文献
10.
The genetic diversity and population structure of the vulnerable Chinese Egret (Egretta eulophotes) were surveyed in the present study from three archipelagoes that cover the most southerly to the very northerly parts of
the Chinese distribution range of this species, using a 433-bp fragment of the mitochondrial control region (CR). Among 90
individual samples, 31 different haplotypes were defined by 30 polymorphic sites. Overall haplotype diversity, nucleotide
diversity and mean sequence divergence (p-distance) of this egret were 0.920, 0.0088 and 1.11%, respectively. NJ tree and
parsimony network for the CR haplotypes of the Chinese Egret showed little genetic structure, and analysis of molecular variance
indicated low but significant genetic differentiation (haplotype-based ΦST = 0.03267, P < 0.05 and distance-based ΦST = 0.04194, P < 0.05) among populations. The significant Fu’s F
S
tests (Fu’s F
S
= −16.946, P < 0.01) and mismatch distribution analysis (τ = 4.463, SSD = 0.0081, P = 0.12) suggested that the low genetic differentiation and little geographical structure of the genetic differentiation might
be explained by the population expansion. The Mantel test (haplotype-based F
ST, r = 0.639, P = 0.34 and distance-based F
ST, r = 0.947, P = 0.15) suggest that the significant genetic differentiation among populations was likely due to isolation by distance. 相似文献
11.
Relationship between seed yield heterosis and molecular marker heterozygosity in soybean 总被引:6,自引:0,他引:6
F. J. Cerna S. R. Cianzio A. Rafalski S. Tingey D. Dyer 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(3):460-467
In soybean [Glycine max (L.) Merr.] heterosis has been reported for seed yield. Molecular markers may be useful to select diverse parents for the
expression of heterosis and yield improvement. The objective of this study was to determine if molecular markers could be
used to predict yield heterosis in soybean. From each Maturity Group (MG) II and III, 21 genotypes were selected on the basis
of high yield (HY), different geographic origin (GO), and isozyme loci (ISO) and for diversity in restriction fragment length
polymorphisms (RFLP), and crosses were made within MGs and selection criteria groups to obtain 6 F1 hybrids per group. The 21 parents and the 24 F1 hybrids of each MG were evaluated for yield in replicated tests at two locations in 2 years, and midparent heterosis (MPH)
and high-parent heterosis (HPH) estimates were calculated. On the basis of hybrid performance during the first year, 12 parents
(3 per selection criteria group) were chosen in each MG to conduct a second RFLP analysis using 129 probes. Genetic distances
(GDM) for pairs of the 12 genotypes were calculated with this RFLP information and correlated with MPH and HPH estimates. Significant
MPH averages for seed yield were observed in the combined analysis of variance in each of the four selection criteria groups
of MG II, and in the HY, ISO, and GO of MG III. Significant HPH averages were observed only in the ISO and GO groups of MG
II. The greatest frequency of F1 hybrids with significant MPH was observed in the ISO and GO groups of both MGs. For HPH, the greatest frequency was observed
in the ISO group of both MGs. In both MGs, the ISO group had the largest absolute MPH value; the RFLP group had generally
the smallest. The observations indicated that the expression of heterosis in seed yield might be associated with diversity
in the isozyme loci present in the parents. For the genotypes included in the second RFLP analysis, correlations of GDMs with MPH and HPH values on an entry-mean basis were low and not significant, indicating that heterosis in yield may not
be associated with genetic diversity at the molecular level as determined by RFLPs. The results suggest that in soybean, parent
selection on the basis of RFLPs and isozyme loci to exploit heterosis in seed yield may not be feasible. There was no association
between genetic distance estimated by the RFLP analysis and seed yield heterosis, and in spite of the observed relationship
between isozyme loci and heterosis for yield, the practicality of using the isozyme markers to select parents may be limited
because of the reduced number of assayable isozyme loci in soybean.
Received: 8 March 1996 / Accepted: 21 February 1997 相似文献
12.
T. L. Wang R. Hagqvist P. M. A. Tigerstedt 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,92(3-4):471-476
Hybrid breeding is an effective approach in many agricultural crops. In allogamous tree species severe inbreeding depression and long reproductive cycles generally prohibit its use. However, three generations of selfing in silver birch (Betula pendula Roth) were obtained by forcing trees to flowering under greenhouse conditions. Hybrids were produced by crossing first-, second and third-generation selfed lines. The effects of different levels of parental inbreeding on the growth performance of hybrid families were observed in a 9-year-old field progeny test. Also, provenance crosses were carried out between selfed lines from different parts of Finland and several other European countries. Observations of growth performance of the provenance hybrids were made in the same trial. The results indicated that the mean stem volumes were significantly different between classes of parental in breeding coefficients (FP) (P<0.0001), and were positively correlated with FP (r=0.9106, P<0.05). Within-family variation of the hybrid families decreased with an increase of FP. The performance of the provenance crosses between parents at a relatively close distance did not depart significantly from the standard controls. However, when the cross distance was extended far to the south, hybrids grew faster, indicating either higher heterozygosity or an extended growth period. 相似文献
13.
Heterosis for horticultural traits in Broccoli 总被引:4,自引:0,他引:4
Hale AL Farnham MW Nzaramba MN Kimbeng CA 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,115(3):351-360
Over the last three decades, broccoli (Brassica oleracea L., Italica Group) hybrids made by crossing two inbred lines replaced open-pollinated populations to become the predominant
type of cultivar. The change to hybrids evolved with little or no understanding of heterosis or hybrid vigor in this crop.
Therefore, the purpose of the present study was to determine levels of heterosis expressed by a set of hybrids derived by
crossing relatively elite, modern inbreds (n = 9). An additional objective was to determine if PCR-based marker derived genetic similarities among the parents can be
useful to predict heterosis in this crop. Thirty-six hybrids derived from a diallel mating design involving nine parents were
evaluated for five horticultural characters including the head characteristics of head weight, head stem diameter, and maturity
(e.g., days from transplant to harvest), and the plant vigor characteristics of plant height, and plant width in four environments.
A total of 409 polymorphic markers were generated by 24 AFLP, 23 SRAP and 17 SSR primer combinations. Euclidean distances
between parents were determined based on phenotypic traits. About half of the hybrids exhibited highparent heterosis for head
weight (1–30 g) and stem diameter (0.2–3.5 cm) when averaged across environments. Almost all hybrids showed highparent heterosis
for plant height (1–10 cm) and width (2–13 cm). Unlike other traits, there was negative heterosis for maturity, indicating
that heterosis for this character in hybrids is expressed as earliness. Genetic similarity estimates among the nine parental
lines ranged from 0.43 to 0.71 and were significantly and negatively correlated with highparent heterosis for all traits except
for stem diameter and days from transplant to harvest. Euclidean distances were not correlated with heterosis. With modern
broccoli inbreds, less heterosis was observed for head characteristics than for traits that measured plant vigor. In addition,
genetic similarity based on molecular markers was more highly correlated with plant vigor characteristics than head traits.
Unlike with molecular marker-based estimates of genetic similarity, euclidean distance determined using phenotypic trait data
was not predictive of heterosis. In conclusion, this study has documented heterosis in Brassica oleracea L., and the ability to predict heterosis in this crop using molecular marker-based estimates of genetic similarity among
parents used in producing the hybrid.
The contents of this publication do not necessarily reflect the views or policies of the USDA, nor does the mention of trade
names, commercial products, or organizations imply endorsement by the US Government. The cost of publishing this paper was
defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked as advertisement
solely to indicate this fact. 相似文献
14.
《Saudi Journal of Biological Sciences》2022,29(1):521-525
Wheat (Triticum aestivum L.) is the most important crop for human nutrition that underpins the food safety of Saudi Arabia. The investigation here was to determine heterosis effects using different genetic methods: heterosis over better, mid parents, the genetic advance, and genotype, phenotypic coefficient of variation for estimation some traits among six wheat landraces and their F1 hybrids. In 2019, these landraces were sown using hand and after 100 days, the emasculation and crossing were made among these six landraces using hand emasculation of anthers. In 2020, seeds for these genotypes (six wheat landraces and their F1) were sown under normal irrigation accordingly done in 2019. The results showed that the most important parent was Mabia resulted with the highest value in number of tiller/ plant, 1,000-grain weight, and fresh shoot weight. The highest value of plant height among six parents was Naqra while highest value at the same trait among F1 hybrids was P3 XP6. The estimations of heterosis showed that out of 15 crosses, one cross (P1XP5) was significantly better yield than all crosses for these four traits. The genotype coefficient of variation (GCV) ranged from 12.5% to 8.7% while phenotypic coefficient of variation ranged from 17.7% to 11.3%. The correlation coefficients was found between fresh shoot weight and number of tiller and plant height and umber of tiller. Wild wheat still serve as a source of useful germplasm with proven adaption and productivity and thus assembles of the wild wheat assortments are the initial step of breeding program. 相似文献
15.
Sal (Shorea robusta Gaertn., Dipterocarpaceae) is a wind-pollinated tropical tree species found in southern Asia. We investigated the genetic
diversity and structure at four microsatellites of 15 populations comprising continuous-peripheral and disjunct-peripheral
populations in Nepal. Estimates of genetic diversity (N
A = 8.98, H
O = 0.62, H
E = 0.69) were similar when compared with those of other tropical tree species. A higher level of genetic diversity was observed
in continuous-peripheral populations (N
A = 9.61, H
O = 0.67, H
E = 0.72) as compared to disjunct-peripheral (N
A = 8.04, H
O = 0.55, H
E = 0.64). Population differentiation was higher among disjunct-peripheral populations (F
ST = 0.043) than among continuous peripherals (F
ST = 0.012). There was a significant association between gene flow distances and genetic differentiation (r
2 = 0.128, P ≤ 0.007). No spatial arrangement of populations according to their geographical locations was found. Based on observed genetic
diversity protection of some populations in continuous-peripheral range are suggested for the sustainable conservation of
genetic resources of the species while protection of some disjunct-peripheral populations are also recommended for conserving
rare alleles. 相似文献
16.
Identification of differentially expressed proteins between hybrid and parents in wheat (Triticum aestivum L.) seedling leaves 总被引:2,自引:0,他引:2
Song X Ni Z Yao Y Zhang Y Sun Q 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(2):213-225
In spite of commercial use of heterosis in agriculture, the molecular basis of heterosis is poorly understood. To gain a better
understanding of the molecular basis of wheat heterosis, we carried out a comparative proteomic analysis in seedling leaves
between wheat hybrid and parents. Common wheat (Triticum aestivum L., 2n = 6x = 42, AABBDD) Line 3338 and spelt wheat (Triticum spelta L., 2n = 6x = 42, AABBDD) Line 2463 were used to produce a heterotic F1 hybrid. The expression patterns of the total proteins were compared in seedling leaves between hybrid and its parents by
using two-dimensional gel electrophoresis with two pH ranges for the first dimension separation. Among ~900 protein spots
reproducibly detected, 49 protein spots were identified as being differentially expressed between hybrid and its parental
lines (P < 0.05) for more than 1.5-folds. Six possible modes of differential expression were observed, including high- and low-parent
dominance, underdominance, and overdominance, uniparent silencing and uniparent dominance. Moreover, 30 of the 49 differentially
expressed protein spots were identified, which were involved in metabolism, signal transduction, energy, cell growth and division,
disease and defense, secondary metabolism. These results indicated that wheat hybridization can cause protein expression differences
between hybrid and its parents; these proteins were involved in diverse physiological process pathways, which might be responsible
for the observed heterosis.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
X. Song and Z. Ni have equally contributed to this work. 相似文献
17.
Christopher G. Oakley Sverre Lundemo Jon gren Douglas W. Schemske 《Journal of evolutionary biology》2019,32(6):592-603
The importance of genetic drift in shaping patterns of adaptive genetic variation in nature is poorly known. Genetic drift should drive partially recessive deleterious mutations to high frequency, and inter‐population crosses may therefore exhibit heterosis (increased fitness relative to intra‐population crosses). Low genetic diversity and greater genetic distance between populations should increase the magnitude of heterosis. Moreover, drift and selection should remove strongly deleterious recessive alleles from individual populations, resulting in reduced inbreeding depression. To estimate heterosis, we crossed 90 independent line pairs of Arabidopsis thaliana from 15 pairs of natural populations sampled across Fennoscandia and crossed an additional 41 line pairs from a subset of four of these populations to estimate inbreeding depression. We measured lifetime fitness of crosses relative to parents in a large outdoor common garden (8,448 plants in total) in central Sweden. To examine the effects of genetic diversity and genetic distance on heterosis, we genotyped parental lines for 869 SNPs. Overall, genetic variation within populations was low (median expected heterozygosity = 0.02), and genetic differentiation was high (median FST = 0.82). Crosses between 10 of 15 population pairs exhibited significant heterosis, with magnitudes of heterosis as high as 117%. We found no significant inbreeding depression, suggesting that the observed heterosis is due to fixation of mildly deleterious alleles within populations. Widespread and substantial heterosis indicates an important role for drift in shaping genetic variation, but there was no significant relationship between fitness of crosses relative to parents and genetic diversity or genetic distance between populations. 相似文献
18.
Borzyszkowska J Stanislawska-Sachadyn A Wirtwein M Sobiczewski W Ciecwierz D Targonski R Gruchala M Rynkiewicz A Limon J 《Journal of applied genetics》2012,53(2):175-182
This study examines whether renin-angiotensin-aldosterone system gene polymorphisms: ACE (encoding for angiotensin converting enzyme) c.2306-117_404 I/D, AGTR1 (encoding for angiotensin II type-1 receptor) c.1080*86A>C and CYP11B2 (encoding for aldosterone synthase) c.-344C>T are associated with the extension of coronary atherosclerosis in a group of
647 patients who underwent elective coronary angiography. The extension of CAD was evaluated using the Gensini score. The
polymorphisms were determined by PCR and RFLP assays. The associations between genotypes and the extent of coronary atherosclerosis
were tested by the Kruskal-Wallis test, followed by pairwise comparisons using Wilcoxon test. The population has been divided
into groups defined by: sex, smoking habit, past myocardial infarction, BMI (>, ≤ 25), age (>, ≤ 55), diabetes mellitus, level
of total cholesterol (>, ≤ 200 mg/dl), LDL cholesterol (>, ≤ 130 mg/dl), HDL cholesterol (>, ≤ 40 mg/dl), triglycerides (>,
≤ 150 mg/dl). Significant associations between the ACE c.2306-117_404 I/D polymorphism and the Gensini score in men with high total cholesterol levels (PKruskal-Wallis = 0.008; Padjusted = 0.009), high level of LDL cholesterol (PKruskal-Wallis = 0.016; Padjusted = 0.028) and low level of HDL cholesterol (PKruskal-Wallis = 0.04; Padjusted = 0.055) have been found. No association between the AGTR1 c.1080*86A>C and CYP11B2 c.-344C>T and the Gensini score has been found. These results suggest that men who carry ACE c.2306-117_404 DD genotype and have high total cholesterol, high LDL cholesterol and low HDL cholesterol levels may be predisposed
to the development of more severe CAD. 相似文献
19.
Genetic diversity and differentiation were analyzed in 11 populations of Magnolia stellata (Sieb. and Zucc.) Maxim. (Magnoliaceae) in the Tokai district, Japan. Variation at four nuclear microsatellite (nSSR) loci
was examined, three chloroplast microsatellite (cpSSR) markers were developed and 13 haplotypes identified. The 11 populations
were divided into three groups (A, B and C). Each population within the group was separated less than 40 km. Group B harbored
the highest gene diversity (H) and allelic richness (Ar) for nSSR (H=0.74 and Ar=8.02). Group C had the highest diversity of chloroplast haplotypes (H=0.79 and Ar=6.8): 2.5 times more haplotypes than the other groups. Each population contributed differently to the total diversity, with
respect to nSSR and cpSSR. AMOVA revealed that 58% of haplotypic and 15% of nSSR variation was partitioned among populations
within groups. A Mantel test revealed significant correlations between population pairwise geographic ln(distance) and FST/(1−FST) for both nSSR (r=0.479; P=0.001) and cpSSR (r=0.230; P=0.040). Dendrograms of populations for nSSR, based on Nei’s genetic distance, were constructed using UPGMA and the neighbor-joining
method. These results suggest that populations in group C have diverged from the other populations, while those in group B
are similar to each other. For group B, fragmentation between populations should be avoided in order to maintain gene flow.
For group C, the uniqueness of each population should be given the highest priority when planning genetic conservation measures
for the species. 相似文献
20.
Analysis of transcriptional and epigenetic changes in hybrid vigor of allopolyploid Brassica napus uncovers key roles for small RNAs 下载免费PDF全文
Yifei Shen Shuo Sun Shuijin Hua Enhui Shen Chu‐Yu Ye Daguang Cai Michael P. Timko Qian‐Hao Zhu Longjiang Fan 《The Plant journal : for cell and molecular biology》2017,91(5):874-893