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991.
Soybean oil content QTL mapping and integrating with meta-analysis method for mining genes 总被引:2,自引:0,他引:2
Zhao-ming Qi Qiong Wu Xue Han Ya-nan Sun Xiang-yu Du Chun-yan Liu Hong-wei Jiang Guo-hua Hu Qing-shan Chen 《Euphytica》2011,179(3):499-514
Oil content of soybean was a valuable quantitative trait controlled by multiple genes. Eleven QTLs were detected by both CIM
and MIM method with the population crossed between Charleston and Dong nong594 in recent 3 years (2007, 2008, 2009). Combining
the QTLs collected over the past 20 years, an integrated map of oil-content major QTLs in soybean was established using soymap2,
which was published in 2004, as a reference. Using the software BioMercator ver.2.1, QTLs were projected from their own maps
onto the reference map. In total, ninety-eight QTLs were integrated into soymap2. A meta-analysis method was used to narrow
down the confidence interval, and 20 consensus QTLs and their corresponding markers were obtained. Using a local version of
GENSCAN, 10,137 sequences in the consensus QTL intervals were predicted. With BLAST, these predicted genes were compared to
the International Protein Index database to mine the related genes. The results offer a basis for gene mining and molecular
breeding in soybean. 相似文献
992.
Hamidreza Nooryazdan Hervé Serieys Jacques David Roberto Bacilieri André J. Bervillé 《Euphytica》2011,178(2):159-175
The genetic base of sunflower elite lines is very narrow, due to many years of selection and breeding. To broaden the genetic
diversity of the cultivated sunflower, in 1995 73 wild sunflower populations were crossed with 3 cultivated lines (Testers),
and 219 hybrid offspring’s were evaluated in the field. GCA and SCA effects were computed suggesting for all traits a genetic
potential for improvement through selection. Study of the hybrids revealed that the wild accessions bear different genetic
abilities to combine with the testers for traits of morphological architecture, phenology and yield (seed weight and seed
oil). The variance due to GCA and SCA showed that gene action was additive for days to flowering, branching and plant height.
Genotypes derived from the same geographic origin may have either good or poor general combing ability. The correlation between
GCA and per se genotype performance was positive for all traits except for seed oil content. This was the first attempt to evaluate wild-cultivated
hybrids in sunflower on a large scale and will be the starting point for the management of hybrid Helianthus annuus populations for breeding. GCA and SCA estimations will facilitate the definition of strategies to manage and exploit the
natural diversity for this crop. 相似文献
993.
Genetic impacts under selective breeding of agricultural crops have been frequently investigated with molecular tools, but
inadequate attention has been paid to assess genetic changes under long-term genetic improvement of plant traits. Here we
analyzed allelic changes with respect to wheat trait improvement in 78 Canadian hard red spring wheat cultivars released from
1845 to 2004 and screened with 370 mapped SSR markers. The improvements in quality, maturity, yield, disease, stem rust, leaf
rust, sawfly resistance, and agronomy were considered. A total of 154 (out of 370) loci with significant allelic changes across
21 chromosomes were detected in the 78 wheat cultivars separated into improved versus non-improved groups for eight traits.
The number of significant loci for improving a trait ranged from four for quality to 68 for yield and averaged 35. Many more
loci with significant allelic reduction for improving a trait were detected than those with significant allelic increase.
Selection for early maturity introduced more alleles, but improving the other traits purged more alleles. Significantly lower
numbers of unique alleles were found in the cultivars with improved traits. The distributions of unique allele counts also
varied greatly across the 21 chromosomes with respect to trait improvement. Significant SSR variation between two cultivar
groups was observed for improvement in seven traits, but not in stem rust. The proportional SSR variation residing between
two groups ranged from 0.014 to 0.118. The proportional SSR variations within the improved cultivar groups consistently were
much lower than those within the non-improved groups. These findings clearly demonstrate the association between allelic changes
and wheat trait improvements and are useful for understanding the genetic modification of the wheat genome by long-term wheat
breeding. 相似文献
994.
This paper offers projections of potential effects of climate change on rusts of wheat and how we should factor in a changing
climate when planning for the future management of these diseases. Even though the rusts of wheat have been extensively studied
internationally, there is a paucity of information on the likely effects of a changing climate on the rusts and their influence
on wheat production. Due to the lack of published empirical research we relied on the few published studies of other plant
diseases, our own unpublished work and relevant information from the vast literature on rusts of wheat to prepare this overview.
Three broad areas of potential risks from a changing climate were described: increased loss from wheat rusts, new rust pathotypes
evolving faster and the reduced effectiveness of rust resistances. Increased biomass of wheat crops grown in the presence
of elevated CO2 concentrations and higher temperatures will increase the leaf area available for attack by the pathogen leading to increased
inoculum production. If changed weather conditions were to accelerate the life cycle of a pathogen, the increased inoculum
can lead to severe rust epidemics in many environments. Likewise should the effects of climate change result in more conducive
conditions for rust development there will also be a corresponding increase in the rate of evolution of new pathotypes which
could increase the rate of appearance of new virulences. The effectiveness of some rust resistance genes is influenced by
temperature and crop development stage. Climate change may directly or indirectly influence the effectiveness of some resistance
genes but this can not be ascertained due to a complete lack of knowledge. Since disease resistance breeding is a long term
strategy it is important to determine if any of the important genes may become less effective due to climate change. Studies
must be made to acquire new information on the rust disease triangle to increase the adaptive capacity of wheat under climate
change. Leadership within the Borlaug Global Rust Initiative (BGRI) is needed to broker research on rust evolution and the
durability of resistance under climate change. 相似文献
995.
Five inbred lines, 10 single cross maize (Zea mays L.) hybrids and two standard cultivars as check were used to study the combining abilities and heterosis under three environmental
conditions. Random amplified polymorphic DNAs (RAPDs) markers were used to study the genetic diversity (GD) and further to
analyze relationship of RAPDs based GD with combining ability and heterosis in short duration maize. Spearman’s rank correlation
coefficients and linear regressions were analyzed to identify the most important factor determining heterosis and per se performance
of the hybrids. Variances due to general combining ability (GCA), specific combining ability (SCA) and their interactions
with environment were found to be significant. Twenty random primers generated 179 RAPD fragments. Of these, 102 RAPD fragments
were polymorphic. GD was determined using Jaccard’s similarity coefficient, and a dendogram was constructed by UPGMA cluster
analysis. The RAPDs based GD exhibited non-significant negative or positive association, non-significant linear regression
along with very low coefficient of determination (R
2) with SCA, high and mid parent heterosis (HP and MP) and per se performance of the hybrids. Significant positive correlations
and regressions along with high coefficients of determination were recorded for SCA with HP, MP and per se performance of
the hybrids. The HP and MP also established significant positive association and linear regression along with high coefficient
of determination with per se performance of hybrids whereas the parental mean did not establish any significant correlations
with the GD, HPH, MPH and grain yield of F1s. The present investigation, therefore, did not find any role of RAPDs based GD in determining hybrid heterosis and hybrid
performance in short duration sub-tropical maize. The SCA, however, has emerged as the most important factor in determination
of heterosis as well as per se performance of the hybrids in short duration maize. 相似文献
996.
Tomatoes are the most important vegetable, globally as well as in Germany. Outdoor tomato production is seriously impaired
due to increasing infections with evolving late blight (Phytophthora infestans) populations. Within organic agriculture, research is being conducted to develop regionally adapted and open pollinated cultivars
of outdoor tomatoes with late blight field resistance. In the present experiment, three crosses, including wild, cocktail,
and beefsteak tomatoes, were selected for field resistance against late blight in F2 at one location per cross. The comparison of positive and negative selection in F3 revealed the selection of single F2 plants to be efficient in all three crosses. F2 selection has proved to be a robust and efficient tool for breeding programs. The correlated response to selection in other
traits, including yield, fruit weight, days to maturity, harvest period, and plant height, depended on the cross. It was evident
that selection for desired traits combined with field resistance against late blight is promising, even in wide crosses. The
most undesired attribute of wild tomatoes is the formation of shoots on leaves and in inflorescences. No correlation was observed
between field resistance and shoot formation, allowing the selection of genotypes with improved field resistance and yield,
but without morphological disadvantages. 相似文献
997.
Tusar K. Behera Jack E. Staub Snigdha Behera Isabelle Y. Delannay Jin Feng Chen 《Euphytica》2011,178(2):261-272
Cucumber (Cucumis sativus L.) is a major cucurbit vegetable species whose genetic base has been drastically reduced during its domestication. The crop’s
narrow genetic base (3–12% DNA polymorphism) has resulted from the use of limited genetic material and intense selection during
plant improvement. Recently, however, interspecific hybridization has been successful in Cucumis via mating of C. hystrix Chakr. and C. sativus, which resulted in the amphidiploid C. hytivus. We report herein a marker-assisted strategy for increasing genetic diversity in cucumber through introgression backcrossing
employing C. hytivus. The comparatively late-flowering but high-yielding, indeterminate, monoecious line WI 7012A (P1; donor parent) derived from a C. hytivus × C. sativus-derived line (long-fruited Chinese C. sativus cv. Beijingjietou) was initially crossed to the determinate, gynoecious C. sativus line WI 7023A (P2; recurrent parent 1), and then advanced backcross generation progeny (BC2) were crossed with the gynoecious indeterminate line WI 9-6A (P3; recurrent parent 2). More specifically, a single F1 individual (P1 × P2) was backcrossed to P2, and then BC progeny were crossed to P2 and P3, where marker-assisted selection (MAS) for genetic diversity (8 mapped and 16 unmapped markers; designated Sel) or no selection
(designated NSel) was applied to produce BC3P2 (Sel) and BC3P3 (Sel), and BC2P2 (NSel) and BC2P2S1 (NSel) progeny. Relative vegetative growth, number of lateral branches (LB), days to flowering (DF), yield (fruit number),
and fruit quality [as measured by length:diameter (L:D) and endocarp:total diameter (E:T) ratios] were assessed in parents
and cross-progeny. DF varied from ~20 (BC3P2Sel) to ~25 days (BC2P3Sel) among the populations examined, where progeny derived from P2 possessed the shortest DF. Differences in cumulative yield among the populations over six harvests were detected, varying
from ~8 fruits per plant in BC3P2 (Sel) to ~39 fruits per plant in BC2P3 (Sel). Although the vigorous vegetative growth of line P1 was observed in its backcross progeny, highly heterozygous and polymorphic backcross progeny derived from P3 were comparatively more vigorous and bore many high-quality fruit. Response to selection was detected for LB, DF, L:D, and
E:T, but the effectiveness of MAS depended upon the parental lines used. Data indicate that the genetic diversity of commercial
cucumber can be increased by introgression of the C. hystrix genome through backcrossing. 相似文献
998.
Sarika Mathure Asif Shaikh N. Renuka Kantilal Wakte Narendra Jawali Ratnakar Thengane Altafhusain Nadaf 《Euphytica》2011,179(2):237-246
Eighty-eight aromatic cultivars collected from Maharashtra state were assessed for determinants of kernel quality (kernel
size-shape, test weight and aroma) and grain morphology such as awning, lemma and palea characters, pubescence, colour of
sterile lemma and apiculus colour. We, report seven cultivars—‘Girga’, ‘Kothmirsal’, ‘Kala bhat’, ‘Chimansal’, ‘Jiri’, ‘Kalsal’
‘Velchi’ and ‘Kali kumud’ as indigenous to southern India. Of the 69 cultivars characterized for agronomic traits 36 cultivars
were exquisite genotypes and possessed one or more superior traits such as early flowering, dwarf stature, higher number of
productive tiller per plant; long panicles; higher number of filled grains per panicle and strong aroma. Variability in aromatic
cultivars was assessed on the basis of nine traits placed aromatic rice cultivars in five clusters. Number of cultivars in
each cluster ranged from 1 to 33. 27 significant correlations were obtained in the physical, agronomic and grain morphology
traits. Aroma was found to be negatively associated with days to 50% flowering as well as with filled grains per panicle.
However, correlation between panicle length and effective tillers with aroma was not observed. Therefore, to increase the
yield, improvement in length of panicle and increasing number of productive tillers in medium or mild scented cultivars would
be the best strategy. 相似文献
999.
Heat stress adversely affects wheat production in many regions of the world and is particularly detrimental during reproductive
development. The objective of this study was to identify novel quantitative trait loci (QTL) associated with improved heat
tolerance in wheat (Triticum aestivum L.) and to confirm previous QTL results. To accomplish this, a recombinant inbred line (RIL) population was subjected to
a three-day 38°C daytime heat stress treatment during early grain-filling. At maturity, a heat susceptibility index (HSI)
was calculated from the reduction of three main spike yield components; kernel number, total kernel weight, and single kernel
weight. The HSI, as well as temperature depression (TD) of the main spike and main flag leaf during heat stress were used
as phenotypic measures of heat tolerance. QTL analysis identified 14 QTL for HSI, with individual QTL explaining from 4.5
to 19.3% of the phenotypic variance. Seven of these QTL co-localized for both TD and HSI. At all seven loci, the allele for
a cooler flag leaf or spike temperature (up to 0.81°C) was associated with greater heat tolerance, indicated by a lower HSI.
In a comparison to previous QTL results in a RIL population utilizing the same source of heat tolerance, seven genome regions
for heat tolerance were consistently detected across populations. The genetic effect of combining three of these QTL, located
on chromosomes 1B, 5A, and 6D, demonstrate the potential benefit of selecting for multiple heat tolerance alleles simultaneously.
The genome regions identified in this study serve as potential target regions for fine-mapping and development of molecular
markers for more rapid development of heat tolerant germplasm. 相似文献
1000.
Self-incompatibility (SI) is a widespread mechanism in flowering plants that promotes outbreeding and thereby increases genetic
diversity. Recognition specificity in Brassica is achieved by the interaction of the female determinant S-receptor kinase (SRK) and its ligand, the male determinant S-locus protein 11 (SP11). The interaction between SP11 and SRK triggers the signaling cascade in an S-haplotype-specific manner and results in the rejection of self-pollen, but the signal components involved are still not well
characterized. S haplotypes are widespread in self-compatible amphidiploid B. napus, and the interaction of heterozygous S haplotypes causes the loss of SI. This review highlights the recent advances made towards understanding the genetic analysis,
distribution, and evolution of S haplotypes, the signal factors, and the potential of SI in B. napus hybrid breeding program. 相似文献