共查询到20条相似文献,搜索用时 31 毫秒
1.
D. Grattapaglia F. L. Bertolucci R. R. Sederoff 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1995,90(7-8):933-947
We have extended the combined use of the “pseudo-testcross” mapping strategy and RAPD markers to map quantitative trait loci (QTLs) controlling traits related to vegetative propagation in Eucalyptus. QTL analyses were performed using two different interval mapping approaches, MAPMAKER-QTL (maximum likelihood) and QTL-STAT (non-linear least squares). A total of ten QTLs were detected for micropropagation response (measured as fresh weight of shoots, FWS), six for stump sprouting ability (measured as # stump sprout cuttings, #Cutt) and four for rooting ability (measured as % rooting of cuttings, %Root). With the exception of three QTLs, both interval-mapping methods yielded similar results in terms of QTL detection. Discrepancies in the most likely QTL location were observed between the two methods. In 75% of the cases the most likely position was in the same, or in an adjacent, interval. Standardized gene substitution effects for the QTLs detected were typically between 0.46 and 2.1 phenotypic standard deviations (σp), while differences between the family mean and the favorable QTL genotype were between 0.25 and 1.07 (σp). Multipoint estimates of the total genetic variation explained by the QTLs (89.0% for FWS, 67.1 % for#Cutt, 62.7% for %Root) indicate that a large proportion of the variation in these traits is controlled by a relatively small number of major-effect QTLs. In this cross, E. grandis is responsible for most of the inherited variation in the ability to form shoots, while E. urophylla contributes most of the ability in rooting. QTL mapping in the pseudo-testcross configuration relies on withinfamily linkage disequilibrium to establish marker/trait associations. With this approach QTL analysis is possible in any available full-sib family generated from undomesticated and highly heterozygous organisms such as forest trees. QTL mapping on two-generation pedigrees opens the possibility of using already existing families in retrospective QTL analyses to gather the quantitative data necessary for marker-assisted tree breeding. 相似文献
2.
Quantitative trait loci (QTL) detection was carried out for adventitious rooting and associated propagation traits in a second-generation
outbred Corymbia torelliana × Corymbia citriodora subspecies variegata hybrid family (n = 186). The parental species of this cross are divergent in their capacity to develop roots adventitiously on stem cuttings
and their propensity to form lignotubers. For the ten traits studied, there was one or two QTL detected, with some QTL explaining
large amounts of phenotypic variation (e.g. 66% for one QTL for percentage rooting), suggesting that major effects influence
rooting in this cross. Collocation of QTL for many strongly genetically correlated rooting traits to a single region on linkage
group 12 suggested pleiotropy. A three locus model was most parsimonious for linkage group 12, however, as differences in
QTL position and lower genetic correlations suggested separate loci for each of the traits of shoot production and root initiation.
Species differences were thought to be the major source of phenotypic variation for some rooting rate and root quality traits
because of the major QTL effects and up to 59-fold larger homospecific deviations (attributed to species differences) relative
to heterospecific deviations (attributed to standing variation within species) evident at some QTL for these traits. A large
homospecific/heterospecific ratio at major QTL suggested that the gene action evident in one cross may be indicative of gene
action more broadly in hybrids between these species for some traits. 相似文献
3.
Mervyn Shepherd Shaowei Huang Peter Eggler Michael Cross Glenn Dale Mark Dieters Robert Henry 《Molecular breeding : new strategies in plant improvement》2006,18(1):11-28
Targeting between-species effects for improvement in synthetic hybrid populations derived from outcrossing parental tree species may be one way to increase the efficacy and predictability of hybrid breeding. We present a comparative analysis of the quantitative trait loci (QTL) which resolved between from within-species effects for adventitious rooting in two populations of hybrids between Pinus elliottii and P. caribaea, an outbred F1 (n=287) and an inbred-like F2 family (n=357). Most small to moderate effect QTL (each explaining 2–5% of phenotypic variation, PV) were congruent (3 out of 4 QTL in each family) and therefore considered within-species effects as they segregated in both families. A single large effect QTL (40% PV) was detected uniquely in the F2 family and assumed to be due to a between-species effect, resulting from a genetic locus with contrasting alleles in each parental species. Oligogenic as opposed to polygenic architecture was supported in both families (60% and 20% PV explained by 4 QTL in the F2 and F1 respectively). The importance of adventitious rooting for adaptation to survive water-logged environments was thought in part to explain oligogenic architecture of what is believed to be a complex trait controlled by many hundreds of genes. 相似文献
4.
In a previous study, several quantitative trait loci (QTLs) affecting vegetative propagation traits were detected in a hybrid
cross between Eucalyptus tereticornis and Eucalyptus globulus. The objective of this work was to confirm stable QTL linked markers (detected in different years) for propagation traits
in an independent set of the same segregating population and in two related crosses involving the original E. globulus parent. Phenotypic averages of groups of individuals carrying alternative allelic forms of the stable QTL linked markers
were statistically tested for significant differences. Adventitious rooting and petrification marker–trait associations, detected
previously in the E. tereticornis parent, were verified in an independent sample of the original progeny. In the E. globulus parent, the QTL linked marker was only verified in one related genetic background. Verification was possible only for high-effect
QTL linked markers. This study highlights the importance of sample size in QTL detection for low-heritability traits. 相似文献
5.
Mareike Knäbel Adam P. Friend John W. Palmer Robert Diack Susan E. Gardiner Stuart Tustin Robert Schaffer Toshi Foster David Chagné 《Tree Genetics & Genomes》2017,13(3):55
The ease of vegetative propagation by hardwood cuttings is a critical trait for consideration by breeders of woody perennial rootstocks. This is especially so for Pyrus, because most Pyrus rootstock are known to be difficult to propagate. This report presents progress on the identification of loci controlling rooting of hardwood cuttings in European pear (Pyrus communis L.). Quantitative trait loci (QTLs) controlling the development of adventitious roots on hardwood cuttings were identified in both parents of a mapping population developed by crossing “Old Home” and “Louise Bonne de Jersey,” with the goal of investigating the genetic control of several rootstock related traits, which would be useful for rootstock breeding. A QTL for root development was identified on chromosome 7, co-located in both parents and exhibiting male and female additive and dominance effects. These results will assist in developing genetic markers that can be utilized by rootstock breeders for marker-assisted selection for this complex trait. 相似文献
6.
Mapping quantitative trait loci controlling seed dormancy and heading date in rice, Oryza sativa L., using backcross inbred lines 总被引:21,自引:0,他引:21
S. Y. Lin T. Sasaki M. Yano 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(8):997-1003
To detect quantitative trait loci (QTLs) controlling seed dormancy, 98 BC1F5 lines (backcross inbred lines) derived from a backcross of Nipponbare (japonica)/Kasalath (indica)//Nipponbare were analyzed genetically. We used 245 RFLP markers to construct a framework linkage map. Five putative QTLs
affecting seed dormancy were detected on chromosomes 3, 5, 7 (two regions) and 8, respectively. Phenotypic variations explained
by each QTL ranged from 6.7% to 22.5% and the five putative QTLs explained about 48% of the total phenotypic variation in
the BC1F5 lines. Except for those of the QTLs on chromosome 8, the Nipponbare alleles increased the germination rate. Five putative
QTLs controlling heading date were detected on chromosomes 2, 3, 4, 6 and 7, respectively. The phenotypic variation explained
by each QTL for heading date ranged from 5.7% to 23.4% and the five putative QTLs explained about 52% of the total phenotypic
variation. The Nipponbare alleles increased the number of days to heading, except for those of two QTLs on chromosomes 2 and
3. The map location of a putative QTL for heading date coincided with that of a major QTL for seed dormancy on chromosome
3, although two major heading-date QTLs did not coincide with any seed dormancy QTLs detected in this study.
Received: 10 October 1997 / Accepted: 12 January 1998 相似文献
7.
Bala R. Thumma Brian S. Baltunis John C. Bell Livinus C. Emebiri Gavin F. Moran Simon G. Southerton 《Tree Genetics & Genomes》2010,6(6):877-889
Tree growth and vegetative propagation are complex but important traits under selection in many tree improvement programmes.
To understand the genetic control of these traits, we conducted a quantitative trait locus (QTL) study in three full-sib families
of Eucalyptus nitens growing at two different sites. One family growing at Ridgley, Tasmania had 300 progeny and two clonally replicated families
growing at Mt. Gambier, South Australia had 327 and 210 progeny. Tree growth was measured over several years at both sites
and percentages of roots produced by either stem cuttings or tissue culture were assessed in the two Mt. Gambier families.
Linkage analysis of growth traits revealed several QTLs for later year traits but few for early year traits, reflecting temporal
differences in the heritabilities of these traits. Two growth QTL positions, one on LG8 and another on LG11 were common between
the Ridgley and Mt. Gambier families. Four QTLs were observed for each of the two vegetative propagation methods. Two QTLs
for vegetative propagation on LG7 and LG11 were validated in the second family at Mt. Gambier. These results suggest that
growth and vegetative propagation traits are controlled by several small effect loci. The QTLs identified in this study are
useful starting points for identifying candidate genes using the Eucalyptus grandis genome sequence. 相似文献
8.
P. Haddadi B. Yazdi-samadi M. R. Naghavi A. Kalantari P. Maury A. Sarrafi 《Plant biotechnology reports》2011,5(2):135-146
The objective of the present research was to map QTLs associated with agronomic traits such as days from sowing to flowering,
plant height, yield and leaf-related traits in a population of recombinant inbred lines (RILs) of sunflower (Helianthus annuus). Two field experiments were conducted with well-irrigated and partially irrigated conditions in randomized complete block
design with three replications. A map with 304 AFLP and 191 SSR markers with a mean density of 1 marker per 3.7 cM was used
to identify QTLs related to the studied traits. The difference among RILs was significant for all studied traits in both conditions.
Three to seven QTLs were found for each studied trait in both conditions. The percentage of phenotypic variance (R
2) explained by QTLs ranged from 4 to 49%. Three to six QTLs were found for each yield-related trait in both conditions. The
most important QTL for grain yield per plant on linkage group 13 (GYP-P-13-1) under partial-irrigated condition controls 49% of phenotypic variance (R
2). The most important QTL for 1,000-grain weight (TGW-P-11-1) was identified on linkage group 11. Favorable alleles for this QTL come from RHA266. The major QTL for days from sowing
to flowering (DSF-P-14-1) were observed on linkage group 14 and explained 38% of the phenotypic variance. The positive alleles for this QTL come from
RHA266. The major QTL for HD (HD-P-13-1) was also identified on linkage group 13 and explained 37% of the phenotypic variance. Both parents (PAC2 and RHA266) contributed
to QTLs controlling leaf-related traits in both conditions. Common QTL for leaf area at flowering (LAF-P-12-1, LAF-W-12-1) was detected in linkage group 12. The results emphasise the importance of the role of linkage groups 2, 10 and 13 for studied
traits. Genomic regions on the linkage groups 9 and 12 are specific for QTLs of leaf-related traits in sunflower. 相似文献
9.
S. Doganlar S. D. Tanksley M. A. Mutschler 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(2):249-255
Using RAPD marker analysis, two quantitative trait loci (QTLs) associated with earliness due to reduced fruit-ripening time
(days from anthesis to ripening = DTR) were identified and mapped in an F2 population derived from a cross between Lycopersicon esculentum’E6203’ (normal ripening) and Lycopersicon esculentum’Early Cherry’ (early ripening). One QTL, on chromosome 5, was associated with a reduction in both ripening time (5 days)
and fruit weight (29.3%) and explained 15.8 and 13% of the total phenotypic variation for DTR and fruit weight, respectively.
The other QTL, on chromosome 12, was primarily associated with a reduction only in ripening time (7 days) and explained 12.3%
of the total phenotypic variation for DTR. The gene action at this QTL was found to be partially dominant (d/a=0.41). Together,
these two QTLs explained 25.1% of the total phenotypic variation for DTR. Additionally, two QTLs associated with fruit weight
were identified in the same F2 population and mapped to chromosomes 4 and 6, respectively. Together, these two QTLs explained 30.9% of the total phenotypc
variation for fruit weight. For all QTLs, the ’Early Cherry’ alleles caused reductions in both ripening time and fruit weight.
The polymorphic band for the most significant RAPD marker (OPAB-06), linked to the reduced ripening time QTL on chromosome
12, was converted to a cleaved amplified polymorphism (CAP) assay for marker-aided selection and further introgression of
early ripening time (DTR) into cultivated tomato.
Received: 15 March 1999 / Accepted: 29 April 1999 相似文献
10.
Meixia Ye Libo Jiang Chixiang Chen Xuli Zhu Ming Wang Rongling Wu 《The Plant journal : for cell and molecular biology》2019,99(4):796-806
Despite its critical importance to our understanding of plant growth and adaptation, the question of how environment‐induced plastic response is affected genetically remains elusive. Previous studies have shown that the reaction norm of an organism across environmental index obeys the allometrical scaling law of part‐whole relationships. The implementation of this phenomenon into functional mapping can characterize how quantitative trait loci (QTLs) modulate the phenotypic plasticity of complex traits to heterogeneous environments. Here, we assemble functional mapping and allometry theory through Lokta?Volterra ordinary differential equations (LVODE) into an R‐based computing platform, np2QTL, aimed to map and visualize phenotypic plasticity QTLs. Based on LVODE parameters, np2QTL constructs a bidirectional, signed and weighted network of QTL?QTL epistasis, whose emergent properties reflect the ecological mechanisms for genotype?environment interactions over any range of environmental change. The utility of np2QTL was validated by comprehending the genetic architecture of phenotypic plasticity via the reanalysis of published plant height data involving 3502 recombinant inbred lines of maize planted in multiple discrete environments. np2QTL also provides a tool for constructing a predictive model of phenotypic responses in extreme environments relative to the median environment. 相似文献
11.
Comparisons between related species with different rooting capacities can provide insights into the mechanisms controlling adventitious root development. The availability of carbohydrates is often considered exclusively as an energetic requirement to drive root development; the major regulatory role in the process is often attributed to phytohormones, particularly auxin. The roles of light quantity (irradiance) and carbohydrate supply available to young aseptic donor-plants on the adventitious rooting response of Eucalyptus globulus (rooting recalcitrant) and Eucalyptus saligna (easy-to-root) were examined. The effects of the type of carbohydrate supply (sucrose or glucose) on the rooting response of cuttings was also evaluated. Light intensity supplied to mother-plants (30 or 60 mol m–2 s–1) had limited influence on the rooting response of both species, whereas dark periods were detrimental, particularly for E. globulus. In E. globulus, rooting was promoted by the absence of sucrose in donor-plant media. Presence of sucrose in donor plant medium promoted root number but did not affect rooting percentage of E. saligna. A positive effect of glucose on cutting rhizogenesis was found if this hexose was supplied during the root induction phase, followed by sucrose in the root formation step, especially for E. globulus. The same effect was not seen with fructose. The beneficial effect of glucose in the induction phase on root number was also evident under suboptimal auxin concentrations. 相似文献
12.
Quantitative trait loci for resistance to herbivores in willow: field experiments with varying soils and climates 总被引:3,自引:0,他引:3
A.C. Rönnberg-Wästljung I. Åhman C. Glynn & O. Widenfalk 《Entomologia Experimentalis et Applicata》2006,118(2):163-174
As a basis for genetic improvement of willow (Salix spp.) for use in wood biomass production, quantitative trait loci (QTLs) responsible for resistance to herbivores have been identified in a tetraploid hybrid F2 population originating from a cross between Salix dasyclados (Wimm.) and Salix viminalis (L.) (Salicaceae). Symptoms of herbivory, caused by various insects and game, and, in addition, leaf rust, were assessed in three field locations with varying soils and climates. Eleven damage traits (lost leaf area, leaf discoloration, leaf blisters, leaf‐mite symptoms, leaf‐margin cuts, and various estimates of shoot‐tip damage by a gall midge, game, and lepidopterans) were submitted to QTL analysis. A composite interval mapping approach was used to estimate the number of QTLs, the magnitude of the QTLs, and their position on genetic linkage maps. Most of the identified QTLs were specific for each trait and location, but a few QTLs common across the locations were also detected. Each QTL explained between 8 and 24% of the phenotypic variation, depending on damage trait and field location. Clusters of QTLs for different traits were found at several linkage groups, indicating either a common genetic base or tightly linked QTL. Our results emphasize the need for verification of QTL studies over different environments. 相似文献
13.
Babu R Nair SK Kumar A Rao HS Verma P Gahalain A Singh IS Gupta HS 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,112(7):1392-1399
Popping expansion volume (PEV) in popcorn (Zea mays L.) is a distinct heritable character and defined as the ratio of the volume after popping to the volume before popping. PEV
is quantitatively inherited and 3–4 genes/quantitative trait loci (QTLs) have been implicated. In the present study, we have
dissected the quantitative PEV into two component traits, viz., flake volume (FV) and percent unpopped kernels (UPK), and
mapped QTLs using SSR markers for all three traits with 194 F3 families derived from a popcorn (A-1-6) × flint corn (V273) cross. Heritability (broad sense) estimates for PEV, FV and UPK
based on F3 mean bases were 0.72, 0.54 and 0.68, respectively. The QTL analyses for the three traits based on combined environment data
were performed by composite interval mapping using QTL cartographer. Four QTLs were identified for PEV on chromosomes 1, 3,
8 and 10, which together explained 62% of the phenotypic variance (σ2p). Four QTLs were found on chromosomes 1, 5, 9 and 10 for FV (explaining 44% of σ2p) and five QTLs for UPK on chromosomes 1, 3, 4, 5 and 9 (explaining 57% of σ2p). The relative efficiency estimates of marker-based selection in comparison to phenotypic selection for PEV (1.10), FV (1.22)
and UPK (1.11) indicated that marker-based selection could be relatively more efficient. The QTL on chromosome 1S for PEV
was found to be most significant, where QTLs for hard endosperm starch concentration had been detected earlier.
A. Kumar and H.S. Rao contributed equally to this research work. 相似文献
14.
Uga Y Hanzawa E Nagai S Sasaki K Yano M Sato T 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,124(1):75-86
Specific Indonesian lowland rice (Oryza sativa L.) cultivars elongate thick primary roots on the soil surface of paddy fields. To clarify the genetic factors controlling
soil-surface rooting, we performed quantitative trait locus (QTL) analyses using 124 recombinant inbred lines (RILs) derived
from a cross between Gemdjah Beton, an Indonesian lowland rice cultivar with soil-surface roots, and Sasanishiki, a Japanese
lowland rice cultivar without soil-surface roots. These cultivars and the RILs were tested for soil-surface rooting in a paddy
field. We identified four regions of chromosomes 3, 4, 6, and 7 that were associated with soil-surface rooting in the field.
Among them, one major QTL was located on the long arm of chromosome 7. This QTL explained 32.5–53.6% of the total phenotypic
variance across three field evaluations. To perform fine mapping of this QTL, we measured the basal root growth angle of crown
roots at the seedling stage in seven BC2F3 recombinant lines grown in small cups in a greenhouse. The QTL was mapped between markers RM21941 and RM21976, which delimit
an 812-kb interval in the reference cultivar Nipponbare. We have designated this QTL qSOR1 (quantitative trait locus for SOIL SURFACE ROOTING 1). 相似文献
15.
Zufei Xiao Na Ji Xinzhong Zhang Yanzhen Zhang Yi Wang Ting Wu Xuefeng Xu Zhenhai Han 《Plant Cell, Tissue and Organ Culture》2014,117(1):51-63
For perennial woody plants, softwood cutting is an efficient technique for larger scale propagation and adventitious rooting of cuttings is one of the most crucial steps. To evaluate the significance of juvenility on adventitious rooting, rooting rates was compared between softwood cuttings collected from apomictic seedlings (juvenile), in vitro cultured plants (rejuvenated), suckers (juvenile like) and canopy shoots (adult) of reproductively mature trees in Malus xiaojinensis. After pre-treatment with indole-3-butytric acid (IBA) (3,000 mg L?1) + H2O2 (50 mM), rooting rates in cutting from juvenile, juvenile like and rejuvenated donor plants were significantly higher (>90 %) than that from adult trees. The effects of IBA on adventitious rooting were enhanced significantly by exogenous H2O2. After 15 passages of in vitro subculture, the micro-shoots from adult phase explants were rejuvenated successfully, marked by the elevated expression of miR156 in the leaflets of the micro-shoots. But the rooting ability of rejuvenated micro-shoots was recovered delayed at the 18th or 21st passage of subculture. During the process of rejuvenation, the leaf indole-3-acetic acid contents and the expressions of rooting related genes CKI1, ARRO-1, ARF7 and ARF19 increased significantly. In contrary, the leaf abscisic acid contents decreased. A lack of juvenility is the most important limiting factor governing adventitious rooting of softwood cuttings in apple rootstocks. 相似文献
16.
R. Wu H. D. Bradshaw Jr. R. F. Stettler 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(7):1110-1119
Nursery growth and dry weight were analyzed for F2 genotypes derived from Populus trichocarpa×P. deltoides that have been field tested with clonal replicates in three different environments. The correlations between nursery and
plantation performance differed among the environments, with higher values at Boardman and Clatskanie (both planted with rooted
cuttings) than Puyallup (planted with unrooted cuttings). At Puyallup, nursery height was more strongly associated with plantation
growth than were nursery diameter and dry weight. Yet, this finding was not supported by QTL mapping. A single overdominant
QTL on linkage group G affected the stem height of both seedlings and resprouts in the nursery but showed nonsignificant LOD
scores for plantation height from ages 1 to 5 at Puyallup. A total of four QTLs were identified for nursery diameter, one
of which on linkage group O also controlled plantation basal area at all ages. Two important nursery QTLs on linkage groups
B and G were used to estimate the relative efficiency of marker-assisted selection for plantation productivity. Despite the
fact that they were not detected in the plantation stage, these two QTLs could significantly increase the proportion of the
phenotypic variance explained by plantation QTLs.
Received: 5 February 1998 / Accepted: 1 April 1998 相似文献
17.
Bala R. Thumma Simon G. Southerton John C. Bell John V. Owen Martin L. Henery Gavin F. Moran 《Tree Genetics & Genomes》2010,6(2):305-317
To identify the chromosomal regions affecting wood quality traits, we conducted a genome-wide quantitative trait locus (QTL)
analysis of wood quality traits in Eucalyptus nitens. This information is important to exploit the full potential of the impending Eucalyptus genome sequence. A three generational mapping population consisting of 296 progeny trees was used to identify QTL associated
with several wood quality traits in E. nitens. Thirty-six QTL positions for cellulose content, pulp yield, lignin content, density, and microfibril angle (MFA) were identified
across different linkage groups. On linkage groups (LG)2 and 8, cellulose QTL cluster with pulp yield and extractives QTL
while on LG4 and 10 cellulose and pulp yield QTLs cluster together. Similarly, on LG4, 5, and 6 QTL for lignin traits were
clustered together. At two positions, QTL for MFA, a physical trait related to wood stiffness, were clustered with QTL for
lignin traits. Several cell wall candidate genes were co-located to QTL positions affecting different traits. Comparative
QTL analysis with Eucalyptus globulus revealed two common QTL regions for cellulose and pulp yield. The QTL positions identified in this study provide a resource
for identifying wood quality genes using the impending Eucalyptus genome sequence. Candidate genes identified in this study through co-location to QTL regions may be useful in association
studies. 相似文献
18.
QTL analysis and mapping of pi21, a recessive gene for field resistance to rice blast in Japanese upland rice 总被引:14,自引:0,他引:14
S. Fukuoka K. Okuno 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(2-3):185-190
Field resistance is defined as the resistance that allows effective control of a parasite under natural field conditions and
is durable when exposed to new races of that parasite. To identify the genes for field resistance to rice blast, quantitative
trait loci (QTLs) conferring field resistance to rice blast in Japanese upland rice were detected and mapped using RFLP and
SSR markers. QTL analysis was carried out in F4 progeny lines from the cross between Nipponbare (moderately susceptible, lowland) and Owarihatamochi (resistant, upland).
Two QTLs were detected on chromosome 4 and one QTL was detected on each of chromosomes 9 and 12. The phenotypic variation
explained by each QTL ranged from 7.9 to 45.7% and the four QTLs explained 66.3% of the total phenotypic variation. Backcrossed
progeny lines were developed to transfer the QTL with largest effect using the susceptible cultivar Aichiasahi as a recurrent
parent. Among 82 F3 lines derived from the backcross, resistance segregated in the expected ratio of resistant 1 : heterozygous 2 : susceptible
1. The average score for blast resistance measured in the field was 4.2 ± 0.67, 7.5 ± 0.51and 8.2 ± 0.66, for resistant, heterozygous
and susceptible groups, respectively. The resistance gene, designated pi21, was mapped on chromosome 4 as a single recessive gene between RFLP marker loci G271 and G317 at a distance of 5.0 cM and 8.5 cM, respectively. The relationship to previously reported major genes and QTLs conferring
resistance to blasts, and the significance of marker-assisted selection to improve field resistance, are discussed.
Received: 8 June 2000 / Accepted: 24 November 2000 相似文献
19.
Yasuhiro Mori Fumihiko Miyahara Yuji Tsutsumi Ryuichiro Kondo 《Plant Growth Regulation》2011,63(3):271-278
Adventitious rooting is essential for cutting propagation of pine wilt-resistant Pinus thunbergii. To examine a variety of adventitious rooting potentials among donor plants, cuttings were taken from 31 seedlings within
a half-sib family. Rooting abilities of cuttings from each seedling ranged from 0 to 100%. When 11 ortets and 11 ramets (clonally
propagated from each ortet) were used as donor plants, there was a positive correlation between rooting abilities of cuttings
from ortets and ramets, suggesting that adventitious rooting is dependent on genetic factors in the donor plants. To promote
adventitious rooting of cuttings by hormonal treatment, we examined the effect of soaking time in Oxyberon (19.7 mM indole-3-butyric
acid (IBA) solution) on rooting. Ten minutes was the best soaking time for rooted cuttings to produce more adventitious roots
without impairing normal growth. When cuttings were soaked in Ethrel diluent (69.2 μM ethephon) for 24 h before soaking in
Oxyberon for 10 min, a significantly higher rooting ability was observed than those soaked in Oxyberon alone. Ethrel on its
own barely affected rooting ability. The positive effect of the combinational treatment was confirmed in a similar experiment
using authentic ethephon and IBA instead of Ethrel and Oxyberon. When cuttings were soaked in a mixture of ethephon and silver
thiosulfate (STS), an ethylene action inhibitor, before IBA-soaking, the effect was partially diminished compared with combinational
treatment without STS. These findings suggest that ethylene action caused by ethephon treatment promotes IBA-mediated adventitious
rooting of P. thunbergii cuttings. 相似文献
20.
Quantitative trait loci controlling aluminium tolerance in two accessions of Arabidopsis thaliana (Landsberg erecta and Cape Verde Islands) 总被引:1,自引:0,他引:1
YURIKO KOBAYASHI YACHIYO FURUTA TAKASHI OHNO TETSUO HARA & HIROYUKI KOYAMA 《Plant, cell & environment》2005,28(12):1516-1524
Quantitative trait loci (QTL) analysis of aluminium (Al) tolerance was performed using Ler/Cvi recombinant inbred (RI) lines of Arabidopsis thaliana. Relative root length (RRL) (root length with 4 µm Al/root length with no Al at pH 5.0) on day 5 was used as the Al tolerance index for QTL analysis. Al tolerance judged by RRL was well correlated to tolerance judged by other indexes, including accumulation of callose, reactive oxygen species in the root apex and growth performance on acid soil containing a large amount of exchangeable Al. Using data sets with an hb2 of 0.91, two QTLs were detected at the top of chromosome 1 and bottom of chromosome 3. These QTLs explained 40 and 16% of the phenotypic variation of Al tolerance, respectively, and the positive effect of the Cvi allele. The QTL on chromosome 1 overlapped with a major QTL in another recombinant inbred population, and is possibly related to malate excretion. A complete pair-wise search revealed 11 sets of epistatic interacting loci pairs, which accounted for the transgressive segregation among the RI population. Several epistatic interactions shared the same chromosomal region, indicating the possible involvement of regulatory proteins in Al tolerance in Arabidopsis. 相似文献